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Haughton PN, Lyng JG, Cronin DA, Morgan DJ, Fanning S, Whyte P. Efficacy of UV light treatment for the microbiological decontamination of chicken, associated packaging, and contact surfaces. J Food Prot 2011; 74:565-72. [PMID: 21477470 DOI: 10.4315/0362-028x.jfp-10-356] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
UV light was investigated for the decontamination of raw chicken, associated packaging, and contact surfaces. The UV susceptibilities of a number of Campylobacter isolates (seven Campylobacter jejuni isolates and three Campylobacter coli isolates), Escherichia coli ATCC 25922, and Salmonella enterica serovar Enteritidis ATCC 10376 in liquid media were also investigated. From an initial level of 7 log CFU/ml, no viable Campylobacter cells were detected following exposure to the most intense UV dose (0.192 J/cm(2)) in liquid media (skim milk subjected to ultrahigh-temperature treatment and diluted 1:4 with maximum recovery diluent). Maximum reductions of 4.8 and 6.2 log CFU/ml were achieved for E. coli and serovar Enteritidis, respectively, in liquid media. Considerable differences in susceptibilities were found between the Campylobacter isolates examined, with variations of up to 4 log CFU/ml being observed. UV treatment of raw chicken fillet (0.192 J/cm(2)) reduced C. jejuni, E. coli, serovar Enteritidis, total viable counts, and Enterobacteriaceae by 0.76, 0.98, 1.34, 1.76, and 1.29 log CFU/g, respectively. Following UV treatment of packaging and surface materials, reductions of up to 3.97, 4.50, and 4.20 log CFU/cm(2) were obtained for C. jejuni, E. coli, and serovar Enteritidis, respectively (P < 0.05). Overall, the color of UV-treated chicken was not significantly affected (P ≥ 0.05). The findings of this study indicate that Campylobacter is susceptible to UV technology and that differences in sensitivities exist between investigated isolates. Overall, UV could be used for improving the microbiological quality of raw chicken and for decontaminating associated packaging and surface materials.
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Farag KW, Lyng JG, Morgan DJ, Cronin DA. Effect of low temperatures (-18 to +5°C) on the texture of beef lean. Meat Sci 2008; 81:249-54. [PMID: 22063991 DOI: 10.1016/j.meatsci.2008.07.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2007] [Revised: 07/21/2008] [Accepted: 07/29/2008] [Indexed: 11/28/2022]
Abstract
The textural properties of beef over the temperature range -18 to +5°C were measured using Warner Bratzler (WB) and tensile techniques. In addition, the effects of rapid radio frequency (RF) tempering and slower conventional air tempering on texture were compared. Temperature showed a significant effect (P<0.05) on WB and tensile shear force, with higher values obtained at temperatures on or below -5°C. Work to fracture values showed two peaks at -15 and -3°C. Sample thickness and muscle fibre direction were also important factors affecting shear force, with samples cut across fibres showing higher values. Tempering method showed no effect (P⩾0.05) on the textural properties measured. In light of the rapid nature of RF tempering, these findings will be of interest to the meat industry.
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Morgan DJ, Hunter DC, McCracken G, McClelland HR, Price JH, Dobbs SP. Is laparoscopically assisted radical vaginal hysterectomy for cervical carcinoma safe? A case control study with follow up. BJOG 2007; 114:537-42. [PMID: 17355358 DOI: 10.1111/j.1471-0528.2007.01291.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To compare a new surgical approach, laparoscopically assisted radical vaginal hysterectomy (LARVH) with open radical hysterectomy in women with cervical cancer. Can selected women benefit from the minimally invasive approach without compromising safety (recurrence rate) and morbidity (complications)? DESIGN Retrospective case control study. SETTING A tertiary referral unit for gynaecological malignancies. POPULATION Thirty women undergoing LARVH were included and compared with 30 women undergoing open radical surgery. The control group was matched for age, body mass index and disease stage. METHODS Retrospective collection of data from patient files and follow up. MAIN OUTCOME MEASURES Recurrence rate, complication rate, hospital stay, nodal counts, blood loss, operating time. RESULTS Recurrence rates were equal (6.7%). There was one death, in the LARVH group. Follow up was mean 31 months in the LARVH group and 30.9 months in the open group. Blood loss as measured by mean drop in haemoglobin was greater in the open group (2.03 versus 3.01 g/dl, P = 0.02). Transfusions were given in 40% of women in the open group and 16.7% in the LARVH group. Hospital stay was significantly less in the LARVH group (5.9 versus 7.8 nights, P = 0.003). Mean operating time was longer in the LARVH group (131 versus 187 minutes P = 0.0001). Mean nodal counts did not differ significantly (17.4 in open vs 14.8 in LARVH, P > 0.05). There were seven perioperative complications in the open group and four in the LARVH group. There have been two recurrences in each group (6.67%) at mean follow up of 31 (LARVH) and 30.9 (open) months. CONCLUSIONS The first 30 LARVH procedures performed in this unit are comparable in terms of safety (recurrence rate and complication rate) and economic factors (shorter hospital stay mitigating longer operating time). Further development of this technique is warranted.
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Bjorksten AR, Crankshaw DP, Morgan DJ, Prideaux PR. The effects of cardiopulmonary bypass on plasma concentrations and protein binding of methohexital and thiopental. ACTA ACUST UNITED AC 2007; 2:281-9. [PMID: 17171861 DOI: 10.1016/0888-6296(88)90306-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effects of cardiopulmonary bypass (CPB) on plasma concentrations and protein binding of methohexital and thiopental were studied during continuous infusions in two groups of ten cardiac surgical patients. Patients were administered an infusion regimen designed to produce a stable total plasma concentration at 5 mg/L for methohexital and 10 mg/L for thiopental. Prior to the commencement of CPB the mean (+/-SD) total plasma methohexital concentration was 5.00 +/- 0.69 mg/L. This fell to 3.12 +/- 0.89 mg/L at two minutes after commencement of CPB, and rose to 4.67 +/- 1.11 mg/L by 75 minutes after commencement of CPB. The unbound fraction rose from 27.1 +/- 5.1% to 42.8 +/- 9.2% at five minutes after the start of CPB, and gradually decreased to 32.1 +/- 4.9% by 75 minutes. The unbound concentration (1.37 +/- 0.32 mg/L) was unaffected by the onset of CPB, being 1.51 +/- 0.49 mg/L at 75 minutes after the start of CPB. Thiopental followed a similar pattern to methohexital, with the total plasma thiopental concentration falling from 9.22 +/- 0.73 mg/L to 4.90 +/- 0.83 mg/L at two minutes after commencement of CPB, and rising again to 7.13 +/- 1.03 mg/L 75 minutes later. During the same period the unbound fraction of thiopental rose from 16.1 +/- 2.5% to 30.3 +/- 7.3% five minutes after the start of CPB, and fell gradually to 22.8 +/- 5.8% after 75 minutes. The unbound concentration (1.51 +/- 0.21 mg/L) was again unchanged by the onset of CPB, being 1.71 +/- 0.29 mg/L at 75 minutes. Plasma protein binding of both drugs correlated strongly with plasma albumin concentration, which decreased by 40% during CPB. It is concluded that hemodilution caused the reduction in total drug concentration and protein binding at the onset of CPB, but that the decrease in protein binding counteracted the dilution of unbound drug, resulting in a stable unbound concentration throughout CPB, and that this effect may be common for barbiturates.
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Morgan DJ, Taylor-Robinson D. Late miscarriage and preterm birth after treatment with clindamycin: a randomised consent design study according to Zelen. BJOG 2006; 113:1483; author reply 1484. [PMID: 17176286 DOI: 10.1111/j.1471-0528.2006.01113.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Morgan DJ, Steele EK, McFaul P. 'All that ulcerates is not herpes simplex'. J OBSTET GYNAECOL 2006; 26:703-4. [PMID: 17071452 DOI: 10.1080/01443610600940307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Guerreiro JB, Santos SB, Morgan DJ, Porto AF, Muniz AL, Ho JL, Teixeira AL, Teixeira MM, Carvalho EM. Levels of serum chemokines discriminate clinical myelopathy associated with human T lymphotropic virus type 1 (HTLV-1)/tropical spastic paraparesis (HAM/TSP) disease from HTLV-1 carrier state. Clin Exp Immunol 2006; 145:296-301. [PMID: 16879249 PMCID: PMC1809672 DOI: 10.1111/j.1365-2249.2006.03150.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Approximately 5% of people infected with human T lymphotropic virus type 1 (HTLV-1) develop clinical myelopathy or tropical spastic paraparesis (HAM/TSP) that is associated with high-levels of Th1 cytokines, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. Chemokines are known to induce cytokine secretion and direct the trafficking of immune cells to sites of disease. The present study measured serum chemokines correlated with autonomously released IFN-gamma in cell cultures. HTLV-1 infection was defined by enzyme-linked immunosorbent assay (ELISA) and confirmed by Western blot. Subjects included HTLV-1 carriers (n = 56), patients with HAM/TSP (n = 31) and healthy HTLV-1 seronegative volunteer controls (n = 20). Serum chemokines and IFN-gamma autonomously released by mononuclear cells in culture were quantified by ELISA. Compared to HTLV-1 carriers, serum chemokines in HAM/TSP patients showed significantly increased levels of CXCL9 and CXCL10, significantly diminished levels of CCL2 and similar amounts of CCL11 and CCL24. In contrast, CCL11 and CCL24 were significantly lower in serum of HAM/TSP patients than either control. IFN-gamma was positively correlated with CXCL9 and CXCL10 when HAM/TSP and HTLV-1 carriers were used as a combined group. However, despite a large proportion of HTLV-1 carriers having high IFN-gamma levels, these chemokines were not increased in carriers. This study showed that high levels of CXCL9 and CXCL10 in the systemic circulation and low serum CCL2 levels are features of HAM/TSP. HTLV-1 infection and Tax and/or additional viral encoded factor-mediated pathological processes triggering T cell activation with autogenous IFN-gamma release are probably involved in regulating chemokine release.
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Taylor-Robinson D, Morgan DJ, Sheehan M, Rosenstein IJ, Lamont RF. Relation between Gram-stain and clinical criteria for diagnosing bacterial vaginosis with special reference to Gram grade II evaluation. Int J STD AIDS 2003; 14:6-10. [PMID: 12590785 DOI: 10.1258/095646203321043183] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The aim of this study was to analyse how the results of Gram-staining vaginal smears correlated with the clinical criteria for determining the existence of bacterial vaginosis (BV) and, in particular, how the category defined as 'intermediate' or Gram grade II did so and its significance. Women attending an antenatal clinic with an abnormal vaginal flora, that is those who had Gram-stains of grades II or III, the latter considered to equate with BV, were given clindamycin or a placebo intravaginally and examined again on up to three occasions. Gram-stain readings of grade III correlated with the clinical criteria for BV on 356 (91.7%) of 388 occasions. Grade II readings covered the spectrum of clinical criteria and correlated with those for BV on 35 (37.2%) of 94 occasions. Grade I, recorded 231 times and seen usually after clindamycin treatment, was associated with BV only once. The sensitivity, specificity, positive predictive value and negative predictive value of the Gram stain for the diagnosis of BV, based on a combination of grades II and III, were 99.7%, 71.6%, 81% and 99.6%, respectively; based on grade III only, the values were 99.7%, 87.7%, 91.6% and 99.6%, respectively. Women reported a malodorous vaginal discharge on 49.2% of the occasions a grade III flora was seen and 13.3% of the times grade II was recorded. It was not associated with grade I and would seem a useful adjunct to the accepted clinical criteria for diagnosing BV. Each of the clinical criteria was found in about equal proportions (87%-91%) for women whose Gram grade was III. For grade II, an increased discharge was noted most often (76.5%) and 'clue' cells least often (24.5%). A positive amine test was the most specific, being associated with <1% of grade I smears. Of women with grade III status, 91% reverted to grade I after treatment with clindamycin for three days. In contrast, of women with grade II status, 53% reverted to grade I, as did 47% of those who were given a placebo. The 'intermediate' (grade II) category is a Gram-stain diagnosis and not one that can be made clinically. It is important to recognize as a distinct entity not only because amalgamation with grade III diminishes the specificity and positive predictive value of the Gram-stain for diagnosing BV, but also because women of grade II status usually fail to respond to clindamycin treatment, whereas those of grade III do not.
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Morgan DJ. Construction and operation of a simple flame-ionization detector for gas chromatography. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0950-7671/38/12/321] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Morgan DJ, Landsberg PT. Derivation of sum rules and hypervirial theorems by differentiation. ACTA ACUST UNITED AC 2002. [DOI: 10.1088/0370-1328/86/2/302] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Blua MJ, Redak RA, Morgan DJ, Costa HS. Seasonal flight activity of two Homalodisca species (Homoptera: Cicadellidae) that spread Xylella fastidiosa in southern California. JOURNAL OF ECONOMIC ENTOMOLOGY 2001; 94:1506-1510. [PMID: 11777056 DOI: 10.1603/0022-0493-94.6.1506] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Homalodisca coagulata (Say) and Homalodisca lacerta (Fowler) are vectors of a new bacterial disease of oleander in California known as oleander leaf scorch, induced by the bacterium Xylella fastidiosa. H. coagulata also has been implicated in the spread of the strain of X. fastidiosa that induces Pierce's disease of grapevines in California. We monitored the flight activity of H. coagulata and H. lacerta in oleander and citrus by using yellow sticky cards at three southern California locations where outbreaks of oleander leaf scorch have been documented, and where vector compliments are different. Areas sampled included a mesic coastal area (Irvine, CA) that supports predominantly H. coagulata and few H. lacerta, a dry inland location (Palm Desert, CA) that supports predominantly H. lacerta and few H. coagulata, and an intermediate area (Riverside, CA) supporting both Homalodisca species. From November 1996 to October 1999 peak catches of both Homalodisca species occurred during the midsummer at all locations. H. coagulata was trapped in greater numbers in citrus than in oleander at both the Riverside and the Irvine sites. Likewise, H. lacerta in Riverside was more associated with citrus than oleander, yet H. lacerta in Palm Desert was trapped in greater numbers in oleander than citrus.
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Lamont RF, Morgan DJ, Logue M, Gordon H. A prospective randomised trial to compare the efficacy and safety of hemabate and syntometrine for the prevention of primary postpartum haemorrhage. Prostaglandins Other Lipid Mediat 2001; 66:203-10. [PMID: 11577783 DOI: 10.1016/s0090-6980(01)00154-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In a prospective, open-label, assessor-blind, randomised parallel group study the efficacy and safety of Hemabate (Pharmacia-Upjohn Pharmaceuticals, Milton Keynes, Buckinghamshire) an analogue of 15-methyl-prostaglandin (PGF2alpha) analogue was compared with Syntometrine (Alliance Pharmaceuticals, Chippenham, Wilts) the standard combination of ergometrine and syntocinon used for the active management of the third stage of labour and the prevention of primary postpartum haemorrhage (PPH). The study was set in a district general hospital with approximately 4,000 deliveries annually. The study was discontinued at the time of the interim analysis because of unacceptable gastrointestinal side effects. At the time of the interim analysis, a total of 529 women had completed the study with 263 randomised to receive PGF2alpha and 266 to receive ergometrine and syntocinon. In a pre-specified subgroup analysis, women delivered vaginally were further subdivided into those considered to be at high or low risk of primary PPH. The measured blood loss and incidence of PPH was similar in both treatment groups whether delivered by caesarean section or vaginally independent of whether women were considered to be at high or low risk. Adverse gastrointestinal events were recorded more often in the Hemabate group. The most common symptom was diarrhoea which occurred in 21% of women who received Hemabate compared to only 0.8% of Syntometrine users. PGF2alpha is as effective as Syntometrine in the prophylaxis of primary PPH in all groups studied but there was a statistically significantly increased risk of diarrhoea among users of PGF2alpha.
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Lukes T, Morgan DJ, Joshua S. Calculation of periodic lattice Green functions with applications to impurity levels in semiconductors. ACTA ACUST UNITED AC 2001. [DOI: 10.1088/0022-3719/4/16/027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Morgan DJ, Vargas SL, Reyes-Mugica M, Walterspiel JN, Carver W, Gigliotti F. Identification of Pneumocystis carinii in the lungs of infants dying of sudden infant death syndrome. Pediatr Infect Dis J 2001; 20:306-9. [PMID: 11303835 DOI: 10.1097/00006454-200103000-00017] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Recently Pneumocystis carinii has been identified in a significant number of infants diagnosed as having died from sudden infant death syndrome (SIDS) in South America and Europe. METHODS We examined lung sections of 79 infants who died with a diagnosis of SIDS in Rochester, NY, and Connecticut for the presence of P. carinii. RESULTS Organisms with a characteristic silver stain appearance for P. carinii were identified in 14% of the lung sections. CONCLUSIONS These data suggest that a possible link between some cases of SIDS and infection with P. carinii should be further evaluated and that infection of young infants may serve as an important reservoir for human P. carinii.
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Powers JM, Rosenblatt DS, Schmidt RE, Cross AH, Black JT, Moser AB, Moser HW, Morgan DJ. Neurological and neuropathologic heterogeneity in two brothers with cobalamin C deficiency. Ann Neurol 2001; 49:396-400. [PMID: 11261516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Two adult brothers, one documented to have methylmalonic acidemia with homocystinuria, or cobalamin C deficiency, after autopsy, displayed severe but divergent neurological presentations. One exhibited a myelopathy and the other chronic endocrine problems (Schmidt's syndrome) followed by a neuropsychiatric and dementing disorder owing to cerebral perivascular demyelination. The recognition of cobalamin C deficiency has practical implications because it is one of the few inherited diseases of central white matter that is treatable.
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Rosenthal MA, Kavar B, Hill JS, Morgan DJ, Nation RL, Stylli SS, Basser RL, Uren S, Geldard H, Green MD, Kahl SB, Kaye AH. Phase I and pharmacokinetic study of photodynamic therapy for high-grade gliomas using a novel boronated porphyrin. J Clin Oncol 2001; 19:519-24. [PMID: 11208846 DOI: 10.1200/jco.2001.19.2.519] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine the recommended dose, toxicity profile, and pharmacokinetics of a novel boronated porphyrin (BOPP) for photodynamic therapy (PDT) of intracranial tumors. PATIENTS AND METHODS BOPP was administered alone in increasing doses (0.25, 0.5, 1.0, 2.0, 4.0, or 8.0 mg/kg) preoperatively in patients with intracranial tumors undergoing postresection PDT until dose-limiting toxicity (DLT) was observed. RESULTS Twenty-nine assessable patients with intracranial tumors received BOPP intravenously 24 hours before surgery. The recommended dose was 4 mg/kg. Dose escalation was limited by thrombocytopenia. The most common nonhematologic toxicity was skin photosensitivity. Pharmacokinetic parameters showed increased area under the plasma concentration-time curve and maximum concentration with increased dose. Tumor BOPP concentrations also increased with increased dose. CONCLUSION BOPP at a dose of 4 mg/kg was well tolerated. DLT was thrombocytopenia, and photosensitivity was the only other toxicity of note. The efficacy of PDT using BOPP requires further exploration.
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Gow PJ, Ghabrial H, Smallwood RA, Morgan DJ, Ching MS. Neonatal hepatic drug elimination. PHARMACOLOGY & TOXICOLOGY 2001; 88:3-15. [PMID: 11169155 DOI: 10.1034/j.1600-0773.2001.088001003.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
After the transition from in utero to newborn life, the neonate becomes solely reliant upon its own drug clearance processes to metabolise xenobiotics. Whilst most studies of neonatal hepatic drug elimination have focussed upon in vitro expression and activities of drug-metabolising enzymes, the rapid physiological changes in the early neonatal period of life also need to be considered. There are dramatic changes in neonatal liver blood flow and hepatic oxygenation due to the loss of the umbilical blood supply, the increasing portal vein blood flow, and the gradual closure of the ductus venosus shunt during the first week of life. These changes which may well affect the capacity of neonatal hepatic drug metabolism. The hepatic expression of cytochromes P450 1A2, 2C, 2D6, 2E1 and 3A4 develop at different rates in the postnatal period, whilst 3A7 expression diminishes. Hepatic glucuronidation in the human neonate is relatively immature at birth, which contrasts with the considerably more mature neonatal hepatic sulfation activity. Limited in vivo studies show that the human neonate can significantly metabolise xenobiotics but clearance is considerably less compared with the older infant and adult. The neonatal population included in pharmacological studies is highly heterogeneous with respect to age, body weight, ductus venosus closure and disease processes, making it difficult to interpret data arising from human neonatal studies. Studies in the perfused foetal and neonatal sheep liver have demonstrated how the oxidative and conjugative hepatic elimination of drugs by the intact organ is significantly increased during the first week of life, highlighting that future studies will need to consider the profound physiological changes that may influence neonatal hepatic drug elimination shortly after birth.
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Ng CY, Ghabrial H, Morgan DJ, Ching MS, Smallwood RA, Angus PW. Right heart failure impairs hepatic elimination of p-nitrophenol without inducing changes in content or latency of hepatic UDP-glucuronosyltransferases. J Pharmacol Exp Ther 2000; 295:830-5. [PMID: 11046125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Congestive heart failure has been shown to affect oxidative drug metabolism, however, there has been little study of its effects on drug conjugation. Using the isolated perfused livers from rats with right ventricular failure (RVF) due to pulmonary artery constriction, we studied the effects of RVF on hepatic elimination of p-nitrophenol (PNP) under controlled flow and oxygen delivery conditions. Hepatic clearance of the drug was found to be significantly impaired in RVF as compared with the sham group (0.80 +/- 0.23 versus 1.28 +/- 0.26 ml/min/g of liver). The impairment of PNP clearance in RVF occurred in parallel with significant reduction in metabolic formation clearance of p-nitrophenyl-beta-D-glucuronide; the major metabolite of PNP (0.51 +/- 0.12 versus 1.03 +/- 0.26 ml/min/g of liver). The intrinsic drug-glucuronidation capacity of livers was evaluated by measuring the microsomal content and activity of the UDP-glucuronosyltransferase(s) (UDP-GT) toward p-nitrophenol. There was no significant difference between sham and the RVF groups in either the content or the activity of the UDP-GT. The latency of the UDP-GT enzymes in microsomes was measured and was found to be similar between the two groups. The results of this study show that RVF impairs hepatic elimination of PNP and that this appears to be independent of changes in hepatic perfusion and oxygenation or alterations in hepatic content, activity, and latency of the UDP-GT.
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Sherman LA, Morgan DJ, Nugent CT, Hernandez FJ, Kreuwel HT, Murtaza A, Ko A, Biggs J. Self-tolerance and the composition of T cell repertoire. Immunol Res 2000; 21:305-13. [PMID: 10852131 DOI: 10.1385/ir:21:2-3:305] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
T cell recognition of self-major histocompatibility complex-peptide complexes dictates the composition of the T cell receptor repertoire. Research projects in our laboratory deal with the mechanisms that regulate the composition of the repertoire specific for self-antigens and the defects that can result in autoimmunity. Two different types of disease models are under investigation: juvenile (type I) diabetes and cancer. Both of these diseases are impacted by the presence of anti-self CD8 cells, yet in opposite ways. By understanding the mechanisms of peripheral tolerance and the reasons they fail in autoimmunity, we may learn how to prevent undesirable autoimmunity and how to encourage an autoimmune response when it is needed to eliminate tumor cells.
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Ng CY, Ghabrial H, Morgan DJ, Ching MS, Smallwood RA, Angus PW. Impaired elimination of propranolol due to right heart failure: drug clearance in the isolated liver and its relationship to intrinsic metabolic capacity. Drug Metab Dispos 2000; 28:1217-21. [PMID: 10997943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
It is unclear if reduced hepatic drug elimination in congestive heart failure is primarily due to impairment of enzyme function as a result of tissue hypoxia, to the direct effects of hepatic congestion, or to changes intrinsic to the liver, such as reductions in enzyme content and activity. We therefore compared propranolol clearance in perfused rat livers from animals with right ventricular failure (RVF) with that from control animals. Despite the fact that both groups were perfused at comparable flow rates, perfusion pressures, and levels of oxygen delivery, hepatic extraction of propranolol was significantly reduced in RVF livers (0.688 +/- 0.122 versus 0.991 +/- 0.006 ml/min/g of liver in controls, P <.001). This effect was reflected in a 97% reduction in propranolol intrinsic clearance in RVF livers (5 +/- 4 versus 172 +/- 82 ml/min/g of liver in controls, P <.01). In RVF livers, total hepatic CYP expression was reduced by 19% compared with controls, whereas cytochrome P450 isoenzymes 1A1/2 and 2D1 were reduced by 41 and 26%, respectively. Despite the 97% reduction in propranolol intrinsic clearance in perfused RVF liver, intrinsic clearance in microsomal preparations from the same livers was reduced by only 48% compared with controls (P <.05). These findings suggest that impaired propranolol clearance in RVF is not primarily accounted for by reduced hepatic oxygen delivery or by changes in hepatic content and activity of drug-metabolizing enzymes.
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Lamont RF, Morgan DJ, Wilden SD, Taylor-Robinson D. Prevalence of bacterial vaginosis in women attending one of three general practices for routine cervical cytology. Int J STD AIDS 2000; 11:495-8. [PMID: 10990331 DOI: 10.1258/0956462001916371] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A prospective observational study of asymptomatic women from three different general practices was set up to establish the incidence of bacterial vaginosis (BV). The study group comprised 287 women recalled to their general practitioner's surgery for routine cervical smears. The prevalence of an abnormal vaginal flora was about the same in women attending the 3 practices. Nearly 14% of women had abnormal vaginal flora and about 9% had BV on gram stain examination of vaginal secretions. This was 2-3 times more common than findings consistent with vaginal candidiasis (3.8%). Significant numbers of women with BV had received antifungal therapy suggesting a misdiagnosis. Because of its potential complications, women should be offered screening for BV in a well-women setting and, if found, should be treated if symptomatic or at risk of adverse obstetric or gynaecological sequelae.
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Morgan DJ, Reitz SR, Atkinson PW, Trumble JT. The resolution of Californian populations of Liriomyza huidobrensis and Liriomyza trifolii (Diptera: Agromyzidae) using PCR. Heredity (Edinb) 2000; 85 ( Pt 1):53-61. [PMID: 10971691 DOI: 10.1046/j.1365-2540.2000.00731.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Liriomyza trifolii (Burgess) and Liriomyza huidobrensis (Blanchard) are important vegetable pests in California. Populations of each species differ in their impact in central and southern regions. This difference may be explained by geographical or host plant differences in each of the regions. We used random amplified polymorphic DNA polymerase chain reactions to assess genetic differences between two laboratory populations of each species collected from central and southern California. Individual L. trifolii from the two regions could be discriminated by the presence/absence of PCR products. No such qualitative differences were apparent in PCR products amplified from L. huidobrensis individuals, but the origins of individuals could be differentiated using a bootstrap analysis of marker frequencies. Marker primers were used to compare field and laboratory individuals. No evidence was found for the existence of further populations or of hybrid populations in central and southern California. The distribution of populations of L. huidobrensis was explained completely by geographical differences. As a consequence of the absence of leafminer infestations on the same host plant varieties in both regions, factors governing L. trifolii population distribution differences were less apparent. The presence of the same host plant varieties at both sites suggests that the two L. trifolii populations differ in host plant preference.
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Gow PJ, Treepongkaruna S, Ghabrial H, Shulkes A, Smallwood RA, Morgan DJ, Ching MS. Neonatal hepatic propranolol elimination: studies in the isolated perfused neonatal sheep liver. J Pharm Sci 2000; 89:586-93. [PMID: 10756324 DOI: 10.1002/(sici)1520-6017(200005)89:5<586::aid-jps4>3.0.co;2-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Using the isolated perfused neonatal sheep liver model, we examined the disposition of propranolol (n = 8, age 0.25-10 days) and compared our findings with our previous study from the perfused near-term fetal sheep liver (Ring JA, et al. 1995. Drug Metab Dispos 23:190-196). Within 45 min of dosage, perfusate propranolol levels had fallen by three orders of magnitude to be less than the limit of detection. Perfusate disappearance curves were monoexponential in six experiments and biexponential in two experiments. The mean shunt-corrected hepatic extraction ratio was 0.92 +/- 0.09, much greater than that seen in the fetal sheep liver (0.26 +/- 0.13, P < 0.0001) but still less than values in the adult sheep (0.97). At the conclusion of the perfusion, 4-hydroxypropranolol was the major metabolite present and 5-hydroxypropranolol and N-desisopropylpropranolol were minor metabolites. We conclude that the isolated perfused neonatal sheep liver is a useful model with which to study the maturation of neonatal hepatic drug oxidation. Our study shows that propranolol is rapidly eliminated by the neonatal liver to form several metabolites at rates far greater than in the fetal liver, but rates of elimination have not yet reached that reported in the adult sheep liver.
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Nugent CT, Morgan DJ, Biggs JA, Ko A, Pilip IM, Pamer EG, Sherman LA. Characterization of CD8+ T lymphocytes that persist after peripheral tolerance to a self antigen expressed in the pancreas. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:191-200. [PMID: 10605011 DOI: 10.4049/jimmunol.164.1.191] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
As a result of expression of the influenza hemagglutinin (HA) in the pancreatic islets, the repertoire of HA-specific CD8+ T lymphocytes in InsHA transgenic mice (D2 mice expressing the HA transgene under control of the rat insulin promoter) is comprised of cells that are less responsive to cognate Ag than are HA-specific CD8+ T lymphocytes from conventional mice. Previous studies of tolerance induction involving TCR transgenic T lymphocytes suggested that a variety of different mechanisms can reduce avidity for Ag, including altered cell surface expression of molecules involved in Ag recognition and a deficiency in signaling through the TCR complex. To determine which, if any, of these mechanisms pertain to CD8+ T lymphocytes within a conventional repertoire, HA-specific CD8+ T lymphocytes from B10.D2 mice and B10.D2 InsHA transgenic mice were compared with respect to expression of cell surface molecules, TCR gene utilization, binding of tetrameric KdHA complexes, lytic mechanisms, and diabetogenic potential. No evidence was found for reduced expression of TCR or CD8 by InsHA-derived CTL, nor was there evidence for a defect in triggering lytic activity. However, avidity differences between CD8+ clones correlated with their ability to bind KdHA tetramers. These results argue that most of the KdHA-specific T lymphocytes in InsHA mice are not intrinsically different from KdHA-specific T lymphocytes isolated from conventional animals. They simply express TCRs that are less avid in their binding to KdHA.
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MESH Headings
- Animals
- Autoantigens/biosynthesis
- CD3 Complex/physiology
- CD8 Antigens/biosynthesis
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Separation
- Clone Cells
- Cytotoxicity, Immunologic/genetics
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/immunology
- Epitopes, T-Lymphocyte/immunology
- H-2 Antigens/immunology
- H-2 Antigens/metabolism
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Hemagglutinin Glycoproteins, Influenza Virus/metabolism
- Immune Tolerance/genetics
- Islets of Langerhans/immunology
- Islets of Langerhans/metabolism
- Mice
- Mice, Transgenic
- Protein Binding/immunology
- Receptors, Antigen, T-Cell/biosynthesis
- Receptors, Antigen, T-Cell/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
- Species Specificity
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- T-Lymphocytes, Cytotoxic/cytology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/metabolism
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Rosenstein IJ, Morgan DJ, Lamont RF, Sheehan M, Doré CJ, Hay PE, Taylor-Robinson D. Effect of intravaginal clindamycin cream on pregnancy outcome and on abnormal vaginal microbial flora of pregnant women. Infect Dis Obstet Gynecol 2000; 8:158-65. [PMID: 10968599 PMCID: PMC1784677 DOI: 10.1155/s1064744900000211] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES To determine whether intravaginal clindamycin cream reduces the incidence of abnormal pregnancy outcome in women with abnormal vaginal microbial flora graded as intermediate or BV and to investigate the effect of the antibiotic on vaginal microbial flora. METHODS A prospective cohort study of pregnant women in an antenatal clinic of a district general hospital. The subjects were 268 women who had abnormal vaginal microbial flora at first clinic visit by examination of a Gram-stained vaginal smear and 34 women with a normal vaginal flora. Two hundred and thirty-seven women were evaluable. Women with abnormal Gram-stained smears (graded as II or III) on clinic recall were randomised to receive treatment (intravaginal clindamycin cream) or placebo and followed to assess outcome of pregnancy, vaginal flora, and detection of Mycoplasma hominis and Ureaplasma urealyticum after treatment. RESULTS Abnormal outcomes of pregnancy were not significantly different in treated and placebo groups by Chi square (P = 0.2). However, women with grade III flora responded better to clindamycin than women with grade II flora by numbers of abnormal outcomes (P = 0.03) and return to normal vaginal flora (P = 0.01) (logistic regression analysis model). This may be due to differences in vaginal bacterial species in these grades. Women whose abnormal vaginal flora had spontaneously returned to normal on follow-up and were therefore not treated (revertants) had as many abnormal outcomes as placebos suggesting that damage by abnormal bacterial species occurred early in pregnancy. CONCLUSIONS Gram-stain screening distinguishing grade II from grade III flora may be helpful in prescribing treatment other than clindamycin for women with grade II flora. Earlier diagnosis and treatment may be more effective in preventing an abnormal outcome, possibly as soon as pregnancy is diagnosed or even offered as a pre-conception screen.
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