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Carroll BJ. Brain mechanisms in manic depression. Clin Chem 1994; 40:303-8. [PMID: 8313611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Manic depressive illness (bipolar disorder) is the mood disorder classically considered to have a strong biological basis. During manic depressive cycles, patients show dramatic fluctuations of mood, energy, activity, information processing, and behaviors. Theories of brain function and mood disorders must deal with the case of bipolar disorder, not simply unipolar depression. Shifts in the nosologic concepts of how manic depression is related to other mood disorders are discussed in this overview, and the renewed adoption of the Kraepelinian "spectrum" concept is recommended. The variable clinical presentations of manic depressive illness are emphasized. New genetic mechanisms that must be considered as candidate factors in relation to this phenotypic heterogeneity are discussed. Finally, the correlation of clinical symptom clusters with brain systems is considered in the context of a three-component model of manic depression.
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Carroll BJ, Chandra M, Phillips EH, Margulies DR. Laparoscopic cholecystectomy in critically ill cardiac patients. Am Surg 1993; 59:783-5. [PMID: 8256928] [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
From August 1989 to January 1993, the authors performed laparoscopic biliary operations in 900 patients, 13 of whom had severe cardiac dysfunction. Nine patients were Goldman Class IV, and four patients were Goldman Class III. Three patients had recent myocardial infarction, five patients were known to have low left ventricular ejection fractions (10%, 21%, 25%, 26%, and 30%), one had severe myocardial ischemia, one had severe congestive heart failure, and one was in profound shock. Nine patients underwent successful laparoscopic cholecystectomy. Laparoscopic cholecystostomies were performed in three patients. One operation was converted to an open cholecystectomy. There was one death within 30 days of surgery. With appropriate hemodynamic monitoring and adequate perioperative support of cardiac function, laparoscopic cholecystectomy can be performed safely for acute cholecystitis in patients with severe cardiac disease. When compared with historical controls, laparoscopic cholecystectomy appears to be safer than open cholecystectomy.
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Carroll BJ, Phillips EH, Chandra M, Fallas M. Laparoscopic transcystic duct balloon dilatation of the sphincter of Oddi. Surg Endosc 1993; 7:514-7. [PMID: 8272998 DOI: 10.1007/bf00316692] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Balloon dilatation of the sphincter of Oddi has been performed via a laparoscopic transcystic duct technique. Small common duct stones and stone debris have been successfully lavaged into the duodenum in 17 of 20 cases (85%) by this method. Postoperative hyperamylasemia was noted in four patients. Mild clinical pancreatitis was observed in three patients (15%). Further evaluation of this technique as an adjunct to laparoscopic common bile duct stone extraction is warranted.
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Carroll BJ, Phillips EH. The early treatment of acute biliary pancreatitis. N Engl J Med 1993; 329:58-9. [PMID: 8505950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Phillips EH, Carroll BJ, Fallas MJ. Laparoscopic preperitoneal inguinal hernia repair without peritoneal incision. Technique and early clinical results. Surg Endosc 1993; 7:159-62. [PMID: 8503071 DOI: 10.1007/bf00594098] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
More than 500,000 hernia procedures are performed annually in the United States alone. The authors have devised a new technique for laparoscopic hernia repair. The peritoneum is not incised, as the space between the abdominal wall and the peritoneum is developed with CO2 and blunt dissection. The trocars and laparoscope are placed within this preperitoneal space. Mesh is stapled to Cooper's ligament and the underside of the abdominal wall. From November 1990 to January 1992, 68 herniae have been repaired in 35 patients. The first 25 patients were kept overnight for observation and discharged the following day. Thirty-two patients (92%) were able to resume full physical activity within 1 week. Average follow-up was only 12 months, but there were no recurrent or retained herniae.
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Phillips EH, Carroll BJ, Fallas MJ. Laparoscopically guided cholecystectomy: a detailed report of the first 453 cases performed by one surgical team. Am Surg 1993; 59:235-42. [PMID: 8489085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study reports outcome data from a diverse population undergoing laparoscopic cholecystectomy. Our technique differs from other laparoscopic methods in its use of electrocautery, blunt hilar dissection, and routine intraoperative cholangiography. This study includes 453 consecutive surgeries performed between August 1989 and March 1991. Only the first 20 patients were screened to exclude those with common bile duct stones, prior upper abdominal surgery, pregnancy, or acute cholecystitis. Patients had the following conditions: current acute cholecystitis (9%), a history of acute cholecystitis (16%), jaundice (5%), pancreatitis (4%), and prior abdominal surgery (38%). Nine per cent had common bile duct stones which were treated with either laparoscopic transcystic common bile duct exploration (69%), laparoscopic choledochotomy (5%), open choledochotomy (10%), endoscopic retrograde cholangiopancreatography (10%), or observation (7%). Operative time averaged 78 minutes. One patient died, and 6% developed complications. Seventy-one per cent were discharged on the first postoperative day. Our experience demonstrates that LC can be performed safely, even in difficult cases, although considerable endoscopic experience and skill are required.
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Klimyuk VI, Carroll BJ, Thomas CM, Jones JD. Alkali treatment for rapid preparation of plant material for reliable PCR analysis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1993; 3:493-494. [PMID: 8220456 DOI: 10.1111/j.1365-313x.1993.tb00169.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
For plant genetics, it would be useful to monitor easily the segregation of different alleles using the polymerase chain reaction (PCR). Preparation of DNA templates from individual plants needs to be rapid and reliable. A one tube protocol is described that involves subjecting plant tissue pieces to alkali, neutralization and heat denaturation prior to PCR analysis, and that proved to be much faster and more reliable than published protocols.
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Phillips EH, Carroll BJ, Pearlstein AR, Daykhovsky L, Fallas MJ. Laparoscopic choledochoscopy and extraction of common bile duct stones. World J Surg 1993; 17:22-8. [PMID: 8447135 DOI: 10.1007/bf01655700] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Various strategies have been proposed for the treatment of common bile duct stones encountered during laparoscopic cholecystectomy (LC). Eighty-three patients who had choledocholithiasis discovered during or just prior to LC are included in this study. These patients were treated by various modalities including preoperative, intraoperative, and postoperative endoscopic retrograde cholangiopancreatography and sphincterotomy, laparoscopic choledochotomy, transcystic duct-common bile duct (TCD-CBD) exploration, and conventional "open" common duct exploration. Sixty-six patients were successfully treated with TCD-CBD exploration. They were discharged on average 2.6 days postoperatively and were able to return to normal physical activities within 7 days of discharge. There was minimal morbidity and no mortality. The technique of TCD-CBD exploration is described in detail. The role of laparoscopic choledochotomy and endoscopic sphincterotomy for management of common duct stones in patients undergoing laparoscopic cholecystectomy appears limited.
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Krishnan KR, Miller MN, Helms MJ, Reed D, Ritchie JC, Nemeroff CB, Carroll BJ. Dose response relationship between plasma ACTH and cortisol after the infusion of ACTH1-24. Eur Arch Psychiatry Clin Neurosci 1993; 242:240-3. [PMID: 8384887 DOI: 10.1007/bf02189969] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The authors examined the dose response relationship between plasma ACTH and cortisol concentrations after the administration of various doses of ACTH1-24 (0.025 micrograms, 0.125 micrograms, 0.25 micrograms, 1 microgram, 250 micrograms) in dexamethasone-suppressed normal volunteers. A logarithmic dose-response relationship between the dose of ACTH administered and plasma cortisol concentration was found. Although there was considerable variability in plasma ACTH concentrations, there was, however, a definite correlation between area under the curve for ACTH and area under the curve for cortisol after the various doses of ACTH.
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Abstract
Fifty-one laparoscopic colectomies were attempted at two institutions. The clinical results and methods are presented. Seven cases (14%) were converted to facilitated procedures, and four cases (8%) were converted to "open." Cases of cancer, diverticulitis, endometriosis, regional enteritis, villous adenomas, and sessile polyps were operated. Right, transverse, left, low anterior, and abdominoperineal colectomies were performed. Colotomies and wedge resections were also performed. Laparoscopic suturing was required in five cases of incomplete anastomosis by circular stapler (18%). Suturing was required in all right, transverse colectomies and colotomies. Operative time averaged 2.3 hours. Hospitalization averaged 4.6 days. Four patients had complications (8%), and one 95-year-old died of pneumonia (2%). Laparoscopic colectomies can be performed safely, but require two-handed laparoscopic coordination, as well as suturing and knot-tying skills.
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Ritchie JC, Owens MJ, Mayer H, Watson JT, Kilts C, Carroll BJ. Preliminary studies of 6 beta-hydroxydexamethasone and its importance in the DST. Biol Psychiatry 1992; 32:825-33. [PMID: 1450296 DOI: 10.1016/0006-3223(92)90086-f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The role of the metabolites of dexamethasone (DEX) in the dexamethasone suppression test (DST) has never been fully elucidated. We report here our preliminary studies of 6 beta-hydroxydexamethasone (6 OH-Dex), a known metabolite of DEX, on the hypothalamic-pituitary-adrenal (HPA) axis of the rat; its activity in the most commonly used radioimmunoassay for plasma DEX; and its plasma concentrations in a normal human subject during the standard 1.0 mg DST. Six OH-Dex administered subcutaneously to rats at a dose of 1 mg/kg was able to completely suppress corticosterone production for at least 3 hr. In the IgG Corp. radioimmunoassay for plasma DEX, 6 OH-Dex was moderately cross-reactive yielding a 50% cross-reactivity of 10%. Gas chromatographic coupled mass spectroscopic analysis of human plasma samples, obtained 12 to 20 hr after the oral ingestion of 1.0 mg DEX, demonstrated similar plasma concentrations for both the parent compound and the 6-hydroxyl metabolite. The relevance of these findings, particularly to pharmacokinetic studies of the DST, is discussed.
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Phillips EH, Carroll BJ, Fallas MM. Common duct stones: removal before or during laparoscopic cholecystectomy? Surg Endosc 1992; 6:266-8. [PMID: 1465739 DOI: 10.1007/bf02498821] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Carroll BJ, Chandra M, Phillips EH, Harold JG. Laparoscopic cholecystectomy in the heart transplant candidate with acute cholecystitis. J Heart Lung Transplant 1992; 11:831-3. [PMID: 1386754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We report the first successful laparoscopic cholecystectomy for treatment of acute cholecystitis in a heart transplant candidate with end-stage heart disease. Eight successful cases of conventional cholecystectomy in heart transplant candidates have been reported, but convalescence after the conventional procedure is prolonged, and morbidity often interferes with a timely heart transplantation. Laparoscopic cholecystectomy is a less-invasive method for treatment of symptomatic cholelithiasis and cholecystitis and may be better tolerated in this patient population. Although further study is needed, we believe laparoscopic cholecystectomy will have applications in patients with end-stage heart disease.
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Abstract
Splenectomy has traditionally been done through a generous laparotomy incision, requiring complete mobilization of the spleen for removal. In selected cases, however, splenectomy may either be facilitated or performed entirely by laparoscopic means. Two patients with Hodgkin's disease in whom splenectomy was facilitated laparoscopically are described; in another patient with idiopathic thrombocytopenic purpura (ITP), the splenectomy was successfully performed through the trocar incisions. In selected cases, laparoscopic splenectomy is feasible, provided the laparoscopist is expert in advanced techniques of intraabdominal endoscopic surgery.
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Phillips EH, Carroll BJ, Bello JM, Fallas MJ, Daykhovsky L. Laparoscopic cholecystectomy in acute cholecystitis. Am Surg 1992; 58:273-6. [PMID: 1535763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Between August 1989 and December 1990, twenty-five patients with a preoperative diagnosis of acute cholecystitis underwent laparoscopic cholecystectomy. Twenty-one patients (84%) had abdominal tenderness, 16 (64%) had leukocytosis, and 10 (40%) had fever. Eleven patients (44%) came to the hospital with only one of these previously mentioned clinical signs. Six patients (24%) had two clinical signs. Eight patients (32%) came to the physician with all three findings. The length of surgery correlated directly with the number of presenting clinical signs. The average operating time was 119 minutes. Intraoperative cholangiograms were routinely performed on all patients. Four patients (16%) had common bile duct stones. The average hospitalization was 3.8 days and patients returned to work or routine physical activity between 3 days and 2 weeks (average 8 days) after surgery. There were three wound infections and two cases of hyperamylasemia. One patient developed urinary retention and another had a CO2 embolus. There were no intra-abdominal abscesses and no mortality. Laparoscopic cholecystectomy in acute cholecystitis is technically difficult. The incidence of common bile duct stones is greater than in elective cases, and routine cholangiography is crucial. With sufficient experience and skill, laparoscopic cholecystectomy can be performed safely in patients with acute cholecystitis.
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Carroll BJ, Phillips EH, Daykhovsky L, Grundfest WS, Gershman A, Fallas M, Chandra M. Laparoscopic choledochoscopy: an effective approach to the common duct. JOURNAL OF LAPAROENDOSCOPIC SURGERY 1992; 2:15-21. [PMID: 1533544 DOI: 10.1089/lps.1992.2.15] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
With increasing acceptance of routine cholangiography during laparoscopic cholecystectomy (for confirmation of anatomy) there has been increased identification of common duct calculi. A technique of laparoscopic transcystic common duct stone extraction is described and early clinical results are presented. Successful stone extraction was accomplished in 39 out of 41 consecutive attempts by one surgical team. Two cases required choledochotomy. There were four complications including hyperamylasemia (2), minor wound infection (1), and incidental pneumothorax (1). Recommendations regarding safety and indications are presented. Initial evaluation suggests laparoscopic transcystic stone extraction is safe and effective.
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Phillips EH, Carroll BJ, Chandra M, Sullivan LA, Ruane PJ, Decker RW, Rosenfelt FP. Laparoscopic-guided biopsy for diagnosis of hepatic candidiasis. JOURNAL OF LAPAROENDOSCOPIC SURGERY 1992; 2:33-8. [PMID: 1533547 DOI: 10.1089/lps.1992.2.33] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Histopathological evaluation of infected tissue is critical in the diagnosis of hepatic candidiasis since cultures are unreliable. Percutaneous techniques are inaccurate because lesions often are small and multifocal, and open biopsy is not always well-tolerated in acutely ill patients. The authors investigated the feasibility of laparoscopically guided biopsy in patients suspected of having hepatic candidiasis. Preliminary results suggest that laparoscopically guided biopsy is highly accurate and less invasive than open biopsy.
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Krishnan KR, Reed D, Wilson WH, Saunders WB, Ritchie JC, Nemeroff CB, Carroll BJ. RU486 in depression. Prog Neuropsychopharmacol Biol Psychiatry 1992; 16:913-20. [PMID: 1325068 DOI: 10.1016/0278-5846(92)90109-r] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
RU486 is a synthetic glucocorticoid antagonist. The authors used RU486 to examine the hypothesis that the elevated plasma cortisol and ACTH in patients is due to suprahypophyseal stimulation of the anterior pituitary. Seven patients and matched controls were studied before and after the administration of RU486. RU486 produced an increase in HPA activity in depressed patients. Thus providing support for the hypothesis that there is increased suprahypophyseal stimulation of the anterior pituitary.
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Krishnan KR, Ritchie JC, Manepalli AN, Saunders W, Li SW, Venkataraman S, Nemeroff CB, Carroll BJ. Fast feedback regulation of ACTH by cortisol. Prog Neuropsychopharmacol Biol Psychiatry 1991; 15:523-9. [PMID: 1661015 DOI: 10.1016/0278-5846(91)90027-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. Fast feedback regulation of ACTH by cortisol has not been well studied in humans. The authors studied the existence and characteristics of fast feedback regulation in normal humans. 2. Hydrocortisone hemisuccinate was infused at two different rates: 6 mg/hour and 12 mg/hour for two hours. 3. The studies did not demonstrate the existence of fast feedback regulation of basal ACTH concentration by cortisol in man. Further, the response was variable and the rate sensitive character was difficult to demonstrate.
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Krishnan KR, Ritchie JC, Manepalli AN, Wilson WH, Saunders WB, Venkataraman SS, Carroll BJ. Role of serotonin in hypothalamo pituitary adrenal axis escape from dexamethasone suppression. Prog Neuropsychopharmacol Biol Psychiatry 1991; 15:637-42. [PMID: 1659724 DOI: 10.1016/0278-5846(91)90053-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. The authors investigated the role of serotonin in the hypothalamo pituitary adrenal escape from depression. 2. Maximal dose of fenfluramine was administered to normal individuals pretreated with dexamethasone. 3. Fenfluramine had only a minimal and inconsistent effect on the hypothalamo pituitary adrenal axis in the presence of dexamethasone.
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Krishnan KR, Ritchie JC, Saunders W, Wilson W, Nemeroff CB, Carroll BJ. Nocturnal and early morning secretion of ACTH and cortisol in humans. Biol Psychiatry 1990; 28:47-57. [PMID: 2165424 DOI: 10.1016/0006-3223(90)90431-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
It is well established that the adrenocorticotropic hormone (ACTH) stimulates the synthesis and release of cortisol from the adrenal cortex, but the role of ACTH in the physiological regulation of basal cortisol secretion has received surprisingly little study. The authors studied the nocturnal and early morning secretory pulses of cortisol and ACTH in normal subjects. A pulse detection algorithm was developed. The relationship between ACTH and cortisol pulses in terms of temporal and proportional relationship is described. Pulse concomitance for ACTH with cortisol was 47% and for cortisol with ACTH pulses it was 60%. The first description of the relationship between concomitant ACTH and cortisol pulse magnitudes in humans is presented. A highly significant linear relationship between the magnitudes of ACTH and cortisol pulses is shown. Putative reasons for dissociated pulses and the potential implication of these findings are discussed.
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Krishnan KR, Ritchie JC, Saunders WB, Nemeroff CB, Carroll BJ. Adrenocortical sensitivity to low-dose ACTH administration in depressed patients. Biol Psychiatry 1990; 27:930-3. [PMID: 2331499 DOI: 10.1016/0006-3223(90)90476-i] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Ritchie JC, Belkin BM, Krishnan KR, Nemeroff CB, Carroll BJ. Plasma dexamethasone concentrations and the dexamethasone suppression test. Biol Psychiatry 1990; 27:159-73. [PMID: 2294980 DOI: 10.1016/0006-3223(90)90646-j] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Altered bioavailability or altered pharmacokinetics of dexamethasone (dex) may contribute to a positive Dexamethasone Suppression Test (DST) in psychiatric patients. We measured plasma dex and plasma cortisol concentrations in 32 patients with primary major depressive disorder (MDD), 14 patients with other psychiatric disorders, and 16 normal controls. Cortisol was measured by the competitive protein binding (CPB) assay and dex by RIA (IgG Corp.). Additionally, cortisol was measured by a fluorescent polarization immunoassay (FPIA) available on the Abbott TDx analyzer in an attempt to validate this method for use in the DST. The agreement between FPIA and CPB cortisol results was excellent. Depressed nonsuppressors, by definition, had significantly higher mean plasma cortisol concentrations than depressed suppressors, psychiatric controls, and normal volunteers at 8:00 AM, 3:00 PM, and 10:00 PM postdex. When DST nonsuppressors and suppressors were compared regardless of diagnostic group, plasma dex concentrations were significantly lower (p less than 0.01) in the DST nonsuppressors. There was a significant negative correlation between plasma cortisol levels and plasma dex levels across all subjects at 8:00 AM (r = -0.365, n = 44, p less than 0.05). When the subjects were sorted by diagnostic category, there was a strong, but not statistically significant, trend toward lower plasma dex concentrations in the melancholic nonsuppressors versus the melancholic suppressors and between the psychiatric control non-suppressors and the corresponding suppressor group. These relationships disappeared when we restricted our analyses to an empirically derived middle range of plasma dex concentrations within which the DST results were considered to be valid. We conclude that bioavailability or pharmacokinetics of dex may significantly contribute to DST results. Further investigation is needed to determine whether or not the quantification of dex and its metabolites and their determination at which specific timepoints during the DST will enhance the predictive or interpretive value of the DST in psychiatric patients.
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Mathews A, Carroll BJ, Gresshoff PM. The genetic interaction between non-nodulation and supernodulation in soybean: an example of developmental epistasis. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1990; 79:125-130. [PMID: 24226131 DOI: 10.1007/bf00223798] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/1989] [Accepted: 08/30/1989] [Indexed: 06/02/2023]
Abstract
The interaction between three non-nodulation mutants (nod49, nod772 and nod139) and a supernodulation mutant (nts382) of soybean was studied by analysing the progeny from crosses between these mutants. Previously it had been shown that the non-nodulation mutants arose from single mutation events and that nod49 and nod772 are allelic, whereas nod139 represents another gene required for nodulation. Analysis of progeny from crosses between nts382 and the wild type showed that this mutant also arose from a single mutation. Complementation tests demonstrated that the mutation responsible for supernodulation in nts382 is not allelic to either of these non-nodulation characters, and that it segregates independently. Progeny were identified that were homozygous for both supernodulation and non-nodulation, and these plants were incapable of nodulation. Thus, non-nodulation is epistatic over supernodulation and this is discussed in terms of the developmental blockage in the two mutant types. The identification and confirmation of these double mutants of the supernodulation and non-nodulation mutations are described. Although the non-nodulation mutations behave as recessive characters in a wild-type background, these mutations are incompletely dominant in a genetic background homozygous for supernodulation. The significance of these results to the understanding of nodule ontogeny is discussed.
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