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Aw MM, Taylor RM, Verma A, Parke A, Baker AJ, Hadzic D, Muiesan P, Rela M, Heaton ND, Mieli-Vergani G, Dhawan A. Basiliximab (Simulect) for the treatment of steroid-resistant rejection in pediatric liver transpland recipients: a preliminary experience. Transplantation 2003; 75:796-9. [PMID: 12660504 DOI: 10.1097/01.tp.0000054682.53834.ea] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND The role of interleukin-2 receptor antibodies as rescue therapy in steroid-resistant rejection (SRR) has not been studied. We evaluated the safety and efficacy of an interleukin-2 receptor antibody, basiliximab (Simulect, Novartis, East Hanover, NJ), in treating SRR in pediatric liver transplant recipients. METHODS This was a prospective study of seven pediatric liver transplant recipients with biopsy-proven SRR who would have otherwise received OKT3 or antithymocyte globulin. The primary immunosuppression consisted of cyclosporine (Neoral, Novartis), azathioprine, and prednisolone in four patients and tacrolimus and prednisolone in three patients who had undergone retransplantation for chronic rejection (n=2) and hyperacute rejection (n=1). Four patients had received two cycles of high-dose steroids, and three patients had received a single cycle; all had been converted to tacrolimus, followed by the addition of mycophenolate mofetil. RESULTS The median time from transplant to SRR was 30 days (range, 8 days-23 months). Five children received two doses of basiliximab (10 mg, 3-7 days apart), and two children received a single dose. Aspartate aminotransferase levels normalized in three children 12, 21, and 30 days after basiliximab treatment. Aspartate aminotransferase levels decreased without normalizing in two children, but there was no further evidence of cellular rejection on repeat biopsies. All five children are rejection-free with a median follow-up of 22 months (range, 5-32 months). Biochemical abnormalities persisted in the remaining two children, and both developed chronic rejection. There were no immediate side effects associated with basiliximab. Two patients were treated empirically for possible cytomegalovirus infection 21 and 57 days after basiliximab treatment, with no evidence of cytomegalovirus disease. CONCLUSION Five of seven pediatric liver transplant recipients with SRR experienced successful outcomes with basiliximab treatment without major side effects, indicating that it is a safe alternative to OKT3 and other antilymphocyte antibodies.
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Dhawan A, Doukas WC. Acute compartment syndrome of the foot following an inversion injury of the ankle with disruption of the anterior tibial artery. A case report. J Bone Joint Surg Am 2003; 85:528-32. [PMID: 12637442 DOI: 10.2106/00004623-200303000-00022] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Dayal M, Parmar D, Dhawan A, Ali M, Dwivedi UN, Seth PK. Effect of pretreatment of cytochrome P450 (P450) modifiers on neurobehavioral toxicity induced by deltamethrin. Food Chem Toxicol 2003; 41:431-7. [PMID: 12504175 DOI: 10.1016/s0278-6915(02)00249-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
To investigate the involvement of cytochrome P450 (P450) enzyme induction and the effect of different P450 modifiers in the neurobehavioral toxicity of deltamethrin, deltamethrin (10 mg/kg; orally for 1 day) was administered to young male albino Wistar rats, or in rats pretreated with phenobarbital (PB; 80 mg/kg, ip for 5 days), an inducer of P450 2B1/2B2 or 3-methylcholanthrene (MC; 30 mg/kg, ip for 5 days), an inducer of P450 1A1/1A2 or cobalt chloride (CoCl(2); sc for 2 days), a depletor of P450s. The administration of PB or MC or CoCl(2) alone did not produced any symptoms of neurobehavioral toxicity. While a single oral administration of deltamethrin produced tremors in two out of 10 rats and decreased the spontaneous locomotor activity, pretreatment with MC or PB potentiated the deltamethrin induced neurobehavioral toxicity with 50% of the treated rats exhibiting tremors. Half of the animals pretreated with MC prior to exposure to deltamethrin also exhibited choreoathetosis. The decrease in the spontaneous locomotor activity was found to be much more significant in PB- or MC-pretreated animals exposed to deltamethrin. In contrast to the pretreatment with inducers, rats pretreated with CoCl(2) exhibited no symptoms of tremors or choreoathetosis, indicating that a reactive metabolite of deltamethrin is formed by P450 catalysed reactions which is involved in the neurobehavioral toxicity of deltamethrin.
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Vanderhyden BC, Macdonald EA, Nagyova E, Dhawan A. Evaluation of members of the TGFbeta superfamily as candidates for the oocyte factors that control mouse cumulus expansion and steroidogenesis. REPRODUCTION (CAMBRIDGE, ENGLAND). SUPPLEMENT 2003; 61:55-70. [PMID: 14635927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Oocytes secrete factors that control cumulus and granulosa functions, including cumulus expansion and steroid hormone production. Some members of the transforming growth factor beta (TGFbeta) superfamily influence these activities, yet it is still not determined conclusively whether any of these superfamily members are the previously reported oocyte-secreted factors. The aim of this study was to examine the effects of TGFbeta1 and growth differentiation factor 9 (GDF-9) on cumulus expansion and progesterone production by mouse oocytectomized (OOX) complexes in culture. TGFbeta1 mimics the effects of oocytes by both enabling cumulus expansion and inhibiting progesterone production; however, neutralizing antibodies to TGFbeta1 in cultures of cumulus-oocyte complexes (COCs) or in co-cultures of OOX complexes failed to inhibit the ability of oocytes to enable cumulus expansion or inhibit progesterone production. Activin A had no effect on progesterone production by OOX complexes. In experiments using oocytes obtained from mice with deficient expression of GDF-9, OOX complexes cultured in the presence of heterozygous oocytes were capable of full expansion, whereas OOX complexes cultured with oocytes from GDF-9 null mice did not expand. Similarly, GDF-9 null oocytes failed to suppress FSH-induced progesterone production by OOX complexes. These results support the hypothesis that GDF-9 is the cumulus expansion enabling factor produced by mouse oocytes and that GDF-9 also inhibits cumulus progesterone production; however, the possibility remains that loss of GDF-9 may indirectly affect the ability of oocytes to produce the factors that regulate cumulus cell activity.
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Malhotra S, Dhawan A, Prakash B. Social support in treatment-seeking heroin-dependent and alcohol dependent patients. INDIAN JOURNAL OF MEDICAL SCIENCES 2002; 56:602-6. [PMID: 14514243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Social support is being recognized as a positive influence on health. It may influence motivation, treatment compliance and outcome in drug dependent patients. On the basis of clinical impression, it was hypothesized that social support in heroin (illicit drug) dependent patients is poorer than in alcohol dependent patients. The current study was undertaken to assess and compare the social support amongst treatment seeking alcohol dependent patients and heroin dependent patients. Despite lesser proportion of patients with any legal source of income in the heroin dependent subject group, the mean social support score across the two study groups was comparable. Overall, the mean social support scores were low in both the groups. The study provides some undestanding about the perceived social support amongst treatment seeking drug dependent individuals from India and also indicates the need to address the issue of social support in substance users.
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Dey A, Parmar D, Dhawan A, Dash D, Seth PK. Cytochrome P450 2E1 dependent catalytic activity and lipid peroxidation in rat blood lymphocytes. Life Sci 2002; 71:2509-19. [PMID: 12270756 DOI: 10.1016/s0024-3205(02)02084-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To investigate the similarities in the catalytic activity of blood lymphocyte P450 2E1 in blood lymphocyte with the liver isoenzyme, NADPH dependent lipid peroxidation and activity of N-nitrosodimethyamine demethylase (NDMA-d) was studied in rat blood lymphocytes. Blood lymphocytes were found to catalyse NADPH dependent (basal) lipid peroxidation and demethylation of N-nitrosodimethylamine (NDMA). Pretreatment with ethanol or pyrazole or acetone resulted in significant increase in the NADPH dependent lipid peroxidation and the activity of NDMA-d in blood lymphocytes and liver microsomes. In vitro addition of CCl(4) to the blood lymphocytes isolated from control or ethanol pretreated rats resulted in an increase in the NADPH dependent lipid peroxidation. Significant inhibition of the basal and CCl(4) supported NADPH dependent lipid peroxidation and NDMA-d activity in blood lymphocytes isolated from control or ethanol pretreated rats by dimethyl formamide or dimethyl sulfoxide or hexane, solvents known to inhibit P450 2E1 catalysed reactions in liver and anti- P450 2E1, have indicated the role of P450 2E1 in the NADPH dependent lipid peroxidation in rat blood lymphocytes. The data indicating similarities in the NADPH dependent lipid peroxidation and NDMA-d activity in blood lymphocyte with the liver microsome have provided evidence that blood lymphocyte P450 2E1 could be used as a surrogate to monitor and predict hepatic levels of the enzyme.
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Taylor RM, Cheeseman P, Rela M, Heaton N, Mieli-Vergani G, Dhawan A. Use of calcineurin inhibitors in pediatric liver transplantation: a single-center experience. Transplant Proc 2002; 34:1974-5. [PMID: 12176652 DOI: 10.1016/s0041-1345(02)03146-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Taylor RM, Bjarnason I, Cheeseman P, Davenport M, Baker AJ, Mieli-Vergani G, Dhawan A. Intestinal permeability and absorptive capacity in children with portal hypertension. Scand J Gastroenterol 2002; 37:807-11. [PMID: 12190094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND Portal hypertension may affect intestinal function leading to malnutrition in children with liver disease. The aim was to determine whether children with portal hypertension with or without liver disease had impaired absorptive capacity and intestinal barrier function (intestinal permeability) and to ascertain whether these abnormalities related to changes in body composition. METHODS Twenty-six children with portal hypertension were divided according to aetiology into: Group 1 intrahepatic (n = 15) and Group 2 prehepatic (n = 11). Thirty-five children acted as controls. Carbohydrate absorption and intestinal permeability were assessed using a sugar absorption/permeability test and a variety of anthropometric measurements were obtained. RESULTS 3-O-methyl-D-glucose, D-xylose and L-rhamnose excretion were significantly reduced in both patient groups compared to controls (P < or = 0.008) and the differential urinary excretion of melibiose/rhamnose (intestinal permeability) was significantly increased in Group 1 only (P < 0.05). Anthropometric measurements showed low Z scores in both groups, but there was no significant (P > 0.05) difference between them. There was no significant correlation between urinary excretion of sugars. anthropometric measurements and energy intake. CONCLUSIONS Increased portal pressure reduces the absorptive capacity of the small intestine, while liver disease itself leads to increased intestinal permeability.
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Taylor RM, Bjarnason I, Cheeseman P, Davenport M, Baker AJ, Mieli-Vergani G, Dhawan A. Intestinal permeability and absorptive capacity in children with portal hypertension. Scand J Gastroenterol 2002. [PMID: 12190094 DOI: 10.1080/gas.37.7.807.811] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Portal hypertension may affect intestinal function leading to malnutrition in children with liver disease. The aim was to determine whether children with portal hypertension with or without liver disease had impaired absorptive capacity and intestinal barrier function (intestinal permeability) and to ascertain whether these abnormalities related to changes in body composition. METHODS Twenty-six children with portal hypertension were divided according to aetiology into: Group 1 intrahepatic (n = 15) and Group 2 prehepatic (n = 11). Thirty-five children acted as controls. Carbohydrate absorption and intestinal permeability were assessed using a sugar absorption/permeability test and a variety of anthropometric measurements were obtained. RESULTS 3-O-methyl-D-glucose, D-xylose and L-rhamnose excretion were significantly reduced in both patient groups compared to controls (P < or = 0.008) and the differential urinary excretion of melibiose/rhamnose (intestinal permeability) was significantly increased in Group 1 only (P < 0.05). Anthropometric measurements showed low Z scores in both groups, but there was no significant (P > 0.05) difference between them. There was no significant correlation between urinary excretion of sugars. anthropometric measurements and energy intake. CONCLUSIONS Increased portal pressure reduces the absorptive capacity of the small intestine, while liver disease itself leads to increased intestinal permeability.
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Wyatt HA, Dhawan A, Cheeseman P, Mieli-Vergani G, Price JF. Serum hyaluronic acid concentrations are increased in cystic fibrosis patients with liver disease. Arch Dis Child 2002; 86:190-3. [PMID: 11861239 PMCID: PMC1719124 DOI: 10.1136/adc.86.3.190] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
AIM To determine whether serum hyaluronic acid (HA) concentrations are abnormal in patients with cystic fibrosis (CF) liver disease, and if so, whether the abnormality is associated with disease severity. METHODS A total of 74 patients with CF were assessed for evidence of liver involvement as indicated by clinical, ultrasound, and biochemical findings. Serum hyaluronic acid concentrations were measured and compared with concentrations in 293 normal controls. Lung function in the CF patients was also recorded. RESULTS Thirty four CF patients had no evidence of liver disease; in these, serum HA concentrations were similar to those in healthy controls (median (range): 16.1 (9.4-75.1) v 15 (1-77) microg/l). Nineteen CF patients had established liver disease detected by clinical and ultrasound examination, with significantly increased HA concentrations (56.1 (26-355) microg/l). Serum HA concentrations were also significantly increased, although to a lesser extent, in 21 CF patients with an abnormal liver ultrasound scan alone (22.4 (9.5-43.4) microg/l). There was no correlation between serum HA concentration and lung function. CONCLUSION Serum HA concentrations were significantly increased in children with clinical or ultrasound evidence of liver disease, being higher in those with more advanced hepatic damage. Despite the inflammation and fibrosis present in CF lungs there was no correlation between HA concentration and lung function, suggesting that high concentrations were a failure of hepatic clearance rather than overproduction in the lung. Longitudinal measurement of HA concentrations may prove a useful marker for the development of significant liver damage in CF patients.
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Dhawan A, Hospodar PP. Isolated posttraumatic posterior dislocation of the radial head in an adult. AMERICAN JOURNAL OF ORTHOPEDICS (BELLE MEAD, N.J.) 2002; 31:83-6. [PMID: 11876282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/17/2023]
Abstract
Isolated posterior dislocation of the radial head without concomitant ulnar fracture or humeroulnar subluxation is a rare injury with few reports in the literature. We describe a case of a 27-year-old man who sustained a traction injury to the right elbow and crush injury to the forearm with subsequent posterior dislocation of the radial head. The dislocation was treated by manual reduction under anesthesia, surgical repair of the annular ligament, and subsequent rehabilitation for 6 weeks in a range-of-motion brace with the forearm in pronation. To our knowledge, this is the only case to be treated this way. Our patient reports excellent range of motion and strength 3 years after surgery.
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Abstract
STUDY DESIGN A retrospective observational study of 279 transpedicular thoracic screws using postoperative computed tomography (CT). OBJECTIVE To determine the accuracy of transpedicular thoracic screws. SUMMARY OF BACKGROUND DATA Previous studies have reported the importance of properly placed transpedicular thoracic screws. To our knowledge, the in vivo accuracy of pedicle screw placement throughout the entire thoracic spine by CT is unknown. METHODS The accuracy of thoracic screw placement within the pedicle and vertebral body and the resultant transverse screw angle (TSA) were assessed by postoperative CT. Cortical perforations of the pedicle were graded in 2-mm increments. Screws were regionally grouped for analysis. RESULTS Forty consecutive patients underwent instrumented posterior spinal fusion using 279 titanium thoracic pedicle screws of various diameters (4.5-6.5 mm). The regional distribution of the screws was 39 screws at T1-T4, 77 screws at T5-T8, and 163 screws at T9-T12. Fifty-seven percent of screws were totally confined within the pedicle. Although medial perforation of the pedicle wall occurred in 14% of screws, in <1% there was >2 mm of canal intrusion. Lateral pedicular perforation occurred in 68% of perforating screws and was significantly more common than medial perforation (P < 0.0005). Seventeen screws penetrated the anterior vertebral cortex by an average of 1.7 mm. Screws inserted between T1 and T4 had a decreased incidence of full containment within the pedicle (P < 0.0005) and vertebral body (P = 0.039) compared with T9-T12. The mean TSA for screws localized within the pedicle was 14.6 degrees and was significantly different from screws with either medial (mean 18.0 degrees ) or lateral (mean 11.5 degrees ) pedicle perforation (P < 0.0005). Anterior vertebral penetration was associated with a smaller mean TSA of 10.1 degrees (P = 0.01) and with lateral pedicle perforation (P < 0.0005). There were no neurologic or vascular complications. CONCLUSIONS Ninety-nine percent of screws were fully contained or were inserted with either < or =2 mm of medial cortical perforation or an acceptable lateral breech using the "in-out-in" technique. Anterior cortical penetration occurred significantly more often with lateral pedicle perforation and with a smaller mean TSA. The incidence of fully contained screws was directly correlated with the region of instrumented thoracic spine.
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Jain R, Dhawan A, Kumar R, Ray R, Singh R. Patients in treatment centres: are they all dependents? Indian J Psychiatry 2001; 43:327-9. [PMID: 21407880 PMCID: PMC2956241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
The congruence between self reported drug use and urinalysis data among 89 consecutive opioid dependents at their first contact in an outpatient clinic was examined. For this purpose self reports of drug use within preceding 72 hr, laboratory analysis of urine samples by thin layer chromatography (TLC) were carried out for various drugs. The same samples were also confirmed by gas liquid chromatography (GLC). Many subjects reported concomitant poly-drug use. The base rate was found to be low for other drugs besides heroin. The conclusion could be dra wn more con vincingly as regard heroin use. Inaccuracy in self-report of drug use has been observed using GLC as a gold standard. The subjects are likely to be more accurate when they report abstinence than when reporting drug use. These results also suggest that clinicians should be cautious while prescribing agonist/partial agonists especially based on only self-report for long term maintenance program, as many patients may not be really physiolologically dependent.
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Aw MM, Samaroo B, Baker AJ, Verma A, Rela M, Heaton ND, Mieli-Vergani G, Dhawan A. Calcineurin-inhibitor related nephrotoxicity- reversibility in paediatric liver transplant recipients. Transplantation 2001; 72:746-9. [PMID: 11544444 DOI: 10.1097/00007890-200108270-00034] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AIM To study the efficacy of mycophenolate mofetil (MMF) as renal rescue in paediatric liver transplant recipients with calcineurin-inhibitor- (CI) related nephrotoxicity. METHODS Pediatric liver transplant recipients with stable graft function and a glomerular filtration rate (GFR) <80 ml/min/1.73 m2 were enrolled. MMF was introduced at 20 mg/kg/day and increased to 40 mg/kg/day after 1 week. CI dose was then reduced 6 weeks to achieve blood levels 25% of baseline. GFR was reassessed after 6 and 12 months. RESULTS Fourteen children with a median (range) interval from transplant of 57 (4-111) months were studied. Their median (range) GFR in ml/min/1.73 m2 increased from a baseline of 52 (31-71), to 69 (38-111) and 73 (35-98) at 6 and 12 months, respectively (P=0.00014). Side effects of MMF include leucopaenia in two and backache in one, two of whom discontinued MMF. Acute allograft rejection occurred in three children. All 14 are well with a median (range) follow-up of 24 (14-38) months from MMF introduction. CONCLUSION MMF allows the recovery of renal function from CI related nephrotoxicity in more than 70% of paediatric liver transplant recipients with renal impairment.
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Dayal M, Parmar D, Ali M, Dhawan A, Dwivedi UN, Seth PK. Induction of rat brain cytochrome P450s (P450s) by deltamethrin: regional specificity and correlation with neurobehavioral toxicity. Neurotox Res 2001; 3:351-7. [PMID: 14715465 DOI: 10.1007/bf03033196] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Oral administration of 5 mg/kg body weight of deltamethrin, an alpha-cyano type II pyrethroid insecticide once a day for 1, 7, 15 and 21 consecutive days to young Druckerey rats (6- 8 weeks old) produced a time dependent increase in the activity of cytochrome P450 (P450) dependent 7-ethoxyresorufin-O-deethylase (EROD) and 7-pentoxyresorufin-O-dealkylase (PROD) in rat brain microsomes. A significant induction was observed on prolonged exposure of deltamethrin for 15 or 21 days. The induction in the activity of cerebral P450 enzymes was associated with the time dependent increase in the spontaneous locomotor activity indicating accumulation of deltamethrin or its metabolites in brain with the increase in the duration of exposure. Administration of deltamethrin (5 mg/kg) for 21 days produced region specific changes in the dealkylation of ethoxyresorufin and pentoxyresorufin in rat brain with significant induction occurring in the activity of P450 1A1/2 dependent EROD in cerebellum, hippocampus, hypothalamus and medulla-pons and that of P450 2B1/2 mediated PROD in hippocampus, hypothalamus, corpus striatum and mid brain. The data suggests that the differences in the induction of individual P450 isoenzymes in diverse brain regions could play a role in regulating the response of brain to pyrethroid insecticides by modulating their concentration per se or their active metabolites at the target site(s).
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Taylor R, Dhawan A. Wilson's disease: from the liver to the brain. NURSING TIMES 2001; 97:38-40. [PMID: 11957950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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Anderson D, Dhawan A, Yardley-Jones A, Ioannides C, Webb J. Effect of antioxidant flavonoids and a food mutagen on lymphocytes of a thalassemia patient without chelation therapy in the Comet assay. TERATOGENESIS, CARCINOGENESIS, AND MUTAGENESIS 2001; 21:165-74. [PMID: 11223893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Thalassemia remains a significant health problem in Europe, the Middle East, and Asia. In such patients, generally high iron levels make free oxygen radicals accessible, for example, through Fenton-type chemistry, and generate superoxide and hydroxyl radicals. Increased oxygen radical capacity is known to be associated with cancer and ageing. It was shown in previous studies that peripheral blood lymphocytes from a sickle/beta thal double heterozygote-sickle phenotype, thalassemia patient, not yet on chelation therapy, were more sensitive to the effects of oxygen radicals and iron salts than lymphocytes from normal controls. Iron overload in thalassemia patients can result from dietary absorption. It was considered that with other dietary agents, such as food mutagens and flavonoids, the thalassemia patient might also show increased sensitivity to the effects of these agents. The present study, therefore, compared the effects of the food mutagen/carcinogen, 3-amino-1-methyl-5H-pyrido(4,3-b)indole (Trp-P-2), in fresh or frozen normal human peripheral lymphocytes with frozen lymphocytes from the same thalassemia patient. The lymphocytes from the thalassemia patient showed an approximately two-fold increase in sensitivity. When a combination of Tryp-P-2, with either quercitin or kaempferol, was compared in frozen lymphocytes and lymphocytes from the thalassemia patient, a two-fold increase in sensitivity was also maintained. Responses to Trp-P-2 were reduced to untreated control levels at the highest doses of quercitin and kaempferol, and were highly significantly different by comparison with Trp-P-2 alone (P<0.001). The flavonoids acted in an antigenotoxic/antioxidant manner. Sensitivity was slightly increased with kaempferol by comparison with quercitin. At low concentrations of the flavonoids there was some evidence of an exacerbation of response, perhaps due to a switch to pro-oxidant status. This exacerbation of response at low doses of flavonoids has been seen in earlier studies with normal lymphocytes. Teratogenesis Carcinog. Mutagen. 21:165-174, 2001.
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Dey A, Parmar D, Dayal M, Dhawan A, Seth PK. Cytochrome P450 1A1 (CYP1A1) in blood lymphocytes evidence for catalytic activity and mRNA expression. Life Sci 2001; 69:383-93. [PMID: 11459429 DOI: 10.1016/s0024-3205(01)01130-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Studies initiated to characterise the catalytic activity and expression of CYP1A1 in rat blood lymphocytes revealed significant activity of 7-ethoxyresorufin-O-deethylase (EROD) in rat blood lymphocytes. Pretreatment with 3-methylcholanthrene (MC) and beta-naphthoflavone (NF) resulted in significant induction in the activity of lymphocyte EROD suggesting that like the liver enzyme, EROD activity in lymphocytes is inducible and is mediated by the MC inducible isoenzymes of P450. The increase in the activity of EROD was associated with a significant increase in the apparent Vmax and affinity of the substrate towards EROD. That this increase in the activity of EROD could be primarily due to the increase in the expression of CYP1A1 isoenzymes was demonstrated by RT-PCR and western immunoblotting studies indicating an increase in the expression of CYP1A1 in blood lymphocytes after MC pretreatment. Significant inhibition in the EROD activity of MC induced lymphocyte by anti-CYP1A1/1A2 and alpha-naphthoflavone further provided evidence that the CYP1A1/1A2 isoenzymes are involved in the activity of EROD in blood lymphocytes. The data indicating similarities in the regulation of CYP1A1 in blood lymphocytes with the liver isoenzyme suggests that factors which may affect expression of CYP1A1 in liver may also affect expression in blood lymphocytes and that blood lymphocytes could be used as a surrogates for studying hepatic expression of the xenobiotic metabolising enzymes.
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Dhawan A, Mieli-Vergani G. Liver transplantation for mitochondrial respiratory chain disorders: to be or not to be? Transplantation 2001; 71:596-8. [PMID: 11292286 DOI: 10.1097/00007890-200103150-00003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Klemme WR, Owens BD, Dhawan A, Zeidman S, Polly DW. Lumbar sagittal contour after posterior interbody fusion: threaded devices alone versus vertical cages plus posterior instrumentation. Spine (Phila Pa 1976) 2001; 26:534-7. [PMID: 11317974 DOI: 10.1097/00007632-200103010-00017] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An observational radiographic study examining lumbar sagittal contour of patients undergoing posterior interbody arthrodesis. OBJECTIVES To compare operative alterations of lumbar sagittal contour after posterior interbody fusion using threaded interbody devices alone versus vertical cages combined with posterior compression instrumentation. SUMMARY OF BACKGROUND DATA Technique-related alterations of lumbar sagittal contour during interbody arthrodesis have received little attention in the spinal literature. METHODS Standing lumbar radiographs were measured for preoperative and postoperative segmental lordosis at levels undergoing posterior interbody arthrodesis using either stand-alone side-by-side threaded devices or vertical cages combined with posterior transpedicular compression instrumentation. Sagittal plane segmental correction (or loss of correction) was calculated and statistically compared. RESULTS The radiographs of 30 patients (34 spinal segments) undergoing lumbar or lumbosacral arthrodesis were compared. Seventeen patients (18 segments) had undergone interbody fusion using threaded cages,whereas 13 patients (16 segments) underwent fusion using vertically oriented mesh cages combined with posterior compression instrumentation. Preoperative segmental lordosis averaged 8 degrees for both groups. For patients undergoing fusion with threaded cages, there was a mean lordotic loss of 3 degrees/segment. For patients undergoing fusion with vertically oriented mesh cages combined with posterior compression instrumentation,there was a mean lordotic gain of 5 degrees/segment. This difference in segmental sagittal plane contour was highly significant (P = 0.00). CONCLUSION Threaded fusion devices placed under interbody distraction with the endplates parallel fail to preserve or reestablish segmental lordosis. Vertical cages, however, when combined with posterior compression instrumentation, not only maintain segmental lordosis, but also can correct sagittal plane deformity.
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Dhawan A, Mathur N, Seth PK. The effect of smoking and eating habits on DNA damage in Indian population as measured in the Comet assay. Mutat Res 2001; 474:121-8. [PMID: 11239969 DOI: 10.1016/s0027-5107(00)00171-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
This study was undertaken with the aim of assessing the status of DNA damage in a normal healthy Indian population. The 62 male volunteers in this study belonged to the smoking, non-smoking, vegetarian and non-vegetarian categories, were well educated and aged between 23 and 57 years. The data revealed significant differences in the extent of DNA damage in the smokers versus non-smokers as well as between the vegetarians and non-vegetarians. A significant difference was also observed amongst the different groups of smokers depending on the extent of smoking. An age-dependent effect in DNA damage was also observed. This preliminary study has, for the first time, revealed differences in the extent of DNA damage in the normal Indian population depending on their eating and smoking habits as well as age.
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Dhawan A, Trivedi P, Cheeseman P, Baker AJ, Howard ER, Mieli-Vergani G. Serum hyaluronic acid as an early prognostic marker in biliary atresia. J Pediatr Surg 2001; 36:443-6. [PMID: 11226992 DOI: 10.1053/jpsu.2001.21622] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE The aim of this study was to assess whether serum concentrations of hyaluronic acid (HA), measured at diagnosis is an early biochemical marker of prognosis in biliary atresia. METHODS Serum HA was measured at diagnosis using a radiometric assay in 84 infants with biliary atresia (BA), and related to outcome by 5 years of age. RESULTS Serum HA was higher in the 29 patients who died or required liver transplant by 5 years of age compared with the 56 who survived to 5 years without transplant (490 +/- 216 microg/L v 262 +/- 163 microg/L; P <.001, 95% confidence intervals of the difference 145 to 311 microg/L). CONCLUSION High serum concentrations of HA at diagnosis may help to identify at an early stage those patients with BA who have a poor prognosis and will require liver transplant by 5 years of age.
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Prachalias AA, Kalife M, Francavilla R, Muiesan P, Dhawan A, Baker A, Hadzic D, Mieli-Vergani G, Rela M, Heaton ND. Liver transplantation for alpha-1-antitrypsin deficiency in children. Transpl Int 2001; 13:207-10. [PMID: 10935704 DOI: 10.1007/s001470050688] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Alpha-1-antitrypsin (a1-AT) deficiency is an inborn error of metabolism, which can cause liver disease. The condition is one of the most common genetic disorders in the Caucasian population. Here we review our experience with 21 children suffering from end-stage liver disease due to a1-AT deficiency. All children are PIZZ homozygotes. Nineteen of them initially presented with neonatal jaundice and two with hepatosplenomegaly in childhood. Twenty-five liver transplantations were performed. All children are currently alive at a median followup of 40 months. Liver replacement provides the only definite treatment for children with end-stage liver disease associated with a1-AT deficiency. Excellent results can be achieved by reducing waiting time for transplantation and by early referral to a liver transplant centre.
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Verma A, Dhawan A, Philpott-Howard J, Rela M, Heaton N, Vergani GM, Wade J. Glycopeptide-resistant Enterococcus faecium infections in paediatric liver transplant recipients: safety and clinical efficacy of quinupristin/dalfopristin. J Antimicrob Chemother 2001; 47:105-8. [PMID: 11152440 DOI: 10.1093/jac/47.1.105] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We describe our experience of quinupristin/dalfopristin for glycopeptide-resistant Enterococcus faecium (GREF) infections in 19 paediatric liver transplant recipients. The median patient age was 2 years and all were receiving immunosuppressive regimens. Quinupristin/dalfopristin was well tolerated and complete resolution of infection was seen in 74% of patients. Side-effects included reversible elevation of serum alkaline phosphatase, skin rash, itching, diarrhoea and vomiting, but therapy was not withdrawn from any patient. Quinupristin/dalfopristin appears safe and efficacious in critically ill immunocompromised children with renal or hepatic impairment.
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