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2.
Zhonghua Er Ke Za Zhi ; 56(7): 534-538, 2018 Jul 02.
Article in Chinese | MEDLINE | ID: mdl-29996188

ABSTRACT

Objective: To explore the correlation between the severity of gastroesophageal reflux cough and degree of gastroesophageal reflux. Methods: A cross-sectional investigation was carried out. Data of 174 cases of chronic cough were collected in Children's Hospital of Fuzhou from March 2009 to December 2016. The esophageal 24 hours pH value dynamic monitoring was used to detect gastric acid reflux index. Cases with abnomal results were divided into mild, moderate and severe groups according to severity of reflux and that of day and night cough symptoms, respectively. They were also divided into infant (1-3 years old), preschool (4-6 years old), and school age (>7 years old) groups according to age. Comparative analysis between groups by chi-square test and rank sum test were performed. Correlation analysis was used to analyze the correlation between cough severity and gastroesophageal reflux index. Results: A total of 174 patients with chronic cough, including 115 males and 59 females, aged from 1 to 15 years with an average age of (8.5±2.3) years, and (1.6±0.8) years of disease duration were enrolled. Among them, 129 cases (74.1%) were positive for esophageal reflux test and 45 cases (25.9%) with no obvious pathological gastroesophageal reflux. Patients with positive esophageal reflux test were divided into severe (n=37, 28.7%), moderate (n=23, 17.8%), and mild (n=69, 53.5%). There was no significant difference in the distribution of gastroesophageal reflux in each age group. (The proportions of mild, moderate and severe reflux in infants were 45.0% (9/20), 25.0% (5/20), and 30.0% (6/20), respectively. The proportions of mild, moderate and severe reflux in preschool children were 53.3% (32/60), 16.7% (10/60), 30.0% (18/60), respectively. The proportions of mild, moderate and severe reflux in school age children were 57.1% (28/49), 16.3% (8/49), 26.5% (13/49), respectively χ(2)=1.204, P=0.877). There was no correlation between age group and gastroesophageal reflux (r=-0.065, P=0.489).The severity of nighttime cough was positively correlated with percentages of distal esophagus pH≤4 in time, recumbent pH≤4 in time, and DeMeester score<14.72 (r=0.689, 0.621, and 0.707 respectively, all P<0.05). There was no statistically significant correlation between the severity of nighttime cough symptoms and percentage of standing pH≤4 in time (r=0.113, P>0.05). There were no statistically significant correlation between the severity of daytime cough and all gastroesophageal reflux markers (all P>0.05). Conclusion: The severity of nocturnal symptoms of gastroesophageal reflux cough is related to the degree of gastroesophageal reflux, to which clinical pediatricians should pay attention.


Subject(s)
Cough , Gastroesophageal Reflux , Adolescent , Child , Child, Preschool , Cough/etiology , Cross-Sectional Studies , Esophageal pH Monitoring , Female , Gastroesophageal Reflux/complications , Humans , Infant , Male
3.
Dis Esophagus ; 29(5): 421-8, 2016 Jul.
Article in English | MEDLINE | ID: mdl-25758922

ABSTRACT

The relationship between occupational asbestos exposure and esophagus cancer (EC) is not fully understood. We performed a meta-analysis to quantitatively assess the association. We systematically searched databases of PubMed, EMBASE, and Web of Science for studies with quantitative estimates of asbestos exposure and EC mortality. Pooled standardized mortality ratios (SMRs) and their corresponding 95% confidence intervals (CIs) were calculated. Twenty cohort studies on EC and asbestos exposure were included in this meta-analysis. Overall, occupational exposure to asbestos was associated with an excess risk of EC (SMR = 1.24, 95% CI: 1.13-1.38, P < 0.001), with little evidence of heterogeneity among studies (I(2) = 0.0%, P = 0.682). Being male, exposure to chrysotile or mixed asbestos, working at textile industry, long study follow-up (≥20 years), Asia, Europe and America cohorts with larger cohort size (>500), and high-exposure group all contribute to significantly higher SMR. Publication bias was not detected (Egger's test P-value = 0.374). This meta-analysis suggested that occupational asbestos exposure might be associated with an increased risk of EC in male. High-exposure level of asbestos could contribute to significantly higher risk of EC mortality.


Subject(s)
Asbestos/adverse effects , Esophageal Neoplasms/mortality , Occupational Diseases/mortality , Occupational Exposure/adverse effects , Adult , Aged , Cohort Studies , Esophageal Neoplasms/etiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Occupational Diseases/etiology , Risk Factors , Sex Factors , Time Factors
4.
Transl Psychiatry ; 4: e376, 2014 Apr 01.
Article in English | MEDLINE | ID: mdl-24690597

ABSTRACT

A number of phosphodiesterase 10A (PDE10) inhibitors are about to undergo clinical evaluation for their efficacy in treating schizophrenia. As phosphodiesterases are in the same signalling pathway as dopamine D2 receptors, it is possible that prior antipsychotic treatment could influence these enzyme systems in patients. Chronic, in contrast to acute, antipsychotic treatment has been reported to increase brain PDE10A levels in rodents. The aim of this study was to confirm these findings in a manner that can be translated to human imaging studies to understand its consequences. Positron emission tomography (PET) scanning was used to evaluate PDE10A enzyme availability, after chronic haloperidol administration, using a specific PDE10A ligand ([(11)C]MP-10). The binding of [(11)C]MP-10 in the striatum and the cerebellum was measured in rodents and a simplified reference tissue model (SRTM) with cerebellum as the reference region was used to determine the binding potential (BPND). In rats treated chronically with haloperidol (2 mg kg(-1) per day), there was no significant difference in PDE10A levels compared with the vehicle-treated group (BPND±s.d.: 3.57 ± 0.64 versus 2.86 ± 0.71). Following PET scans, ex vivo analysis of striatal brain tissue for PDE10A mRNA (Pde10a) and PDE10A enzyme activity showed no significant difference. Similarly, the PDE10A protein content determined by western blot analysis was similar between the two groups, contrary to an earlier finding. The results of the study indicate that prior exposure to antipsychotic medication in rodents does not alter PDE10A levels.


Subject(s)
Antipsychotic Agents/pharmacology , Haloperidol/pharmacology , Neostriatum/drug effects , Neostriatum/metabolism , Phosphoric Diester Hydrolases/metabolism , Animals , Antipsychotic Agents/administration & dosage , Gene Expression/drug effects , Haloperidol/administration & dosage , Neostriatum/diagnostic imaging , Neostriatum/enzymology , Phosphodiesterase Inhibitors , Phosphoric Diester Hydrolases/drug effects , Positron-Emission Tomography , Protein Binding , Pyrazoles , Quinolines , Rats , Rats, Sprague-Dawley
5.
J Hosp Infect ; 64(3): 278-81, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16920222

ABSTRACT

Laser masks are used to prevent inhalation of viral particles during laser surgery. A crossover trial was performed in eight volunteers to compare the ability of a surgical mask and a laser mask with that of an FFP2 respirator to filter airborne dust particles. The surgical and laser masks were tested when worn normally and when they were taped to the face. The mean reductions in particle counts were 3.0 fold [95% confidence interval (95% CI) 1.8-4.2] for the untaped surgical mask, 3.8 fold (95% CI 2.9-4.6) for the untaped laser mask, 7.5 fold (95% CI 6.5-8.5) for the taped surgical mask, 15.6 fold (95% CI 13.5-17.8) for the taped laser mask, and 102.6 fold (95% CI 41.2-164.1) for the FFP2 half-face respirator. The laser mask provided significantly less protection than the FFP2 respirator (P=0.02), and only marginally more protection than the surgical mask. The continued use of laser masks for respiratory protection is questionable. Taping masks to the face only provided a small improvement in protection.


Subject(s)
Infectious Disease Transmission, Patient-to-Professional/prevention & control , Masks/virology , Occupational Exposure/prevention & control , Respiratory Protective Devices/virology , Cross-Over Studies , Dust , Filtration , Humans , Infection Control/methods , Laser Therapy/instrumentation , Masks/standards , Particulate Matter/adverse effects , Particulate Matter/analysis , Prospective Studies , Respiratory Protective Devices/standards
6.
Asian Pac J Allergy Immunol ; 22(1): 11-7, 2004 Mar.
Article in English | MEDLINE | ID: mdl-15366653

ABSTRACT

Airway inflammation can be demonstrated by the modem method of sputum induction using ultrasonic nebulizer and hypertonic saline. We studied whether compressed-air nebulizer and isotonic saline which are commonly available and cost less, are as effective in inducing sputum in normal adult subjects as the above mentioned tools. Sixteen subjects underwent weekly sputum induction in the following manner: ultrasonic nebulizer (Medix Sonix 2000, Clement Clarke, UK) using hypertonic saline, ultrasonic nebulizer using isotonic saline, compressed-air nebulizer (BestNeb, Taiwan) using hypertonic saline, and compressed-air nebulizer using isotonic saline. Overall, the use of an ultrasonic nebulizer and hypertonic saline yielded significantly higher total sputum cell counts and a higher percentage of cell viability than compressed-air nebulizers and isotonic saline. With the latter, there was a trend towards squamous cell contaminations. The proportion of various sputum cell types was not significantly different between the groups, and the reproducibility in sputum macrophages and neutrophils was high (Intraclass correlation coefficient, r [95%CI]: 0.65 [0.30-0.91] and 0.58 [0.22-0.89], p < 0.001). Overall changes in median FEV, were small and comparable between all groups. Induction using ultrasonic nebulizers together with hypertonic saline was generally less well tolerated than compressed-air nebulizers and isotonic saline. We conclude that in normal subjects, although both nebulizers and saline types can induce sputum with reproducible cellular profile, ultrasonic nebulizers and hypertonic saline are more effective but less well tolerated.


Subject(s)
Bronchial Provocation Tests/methods , Nebulizers and Vaporizers , Sputum/drug effects , Ultrasonic Therapy/methods , Administration, Inhalation , Adult , Female , Humans , Isotonic Solutions/administration & dosage , Male , Saline Solution, Hypertonic/administration & dosage , Sodium Chloride/administration & dosage , Sputum/immunology , Treatment Outcome
7.
J Bone Joint Surg Am ; 83(5): 679-87, 2001 May.
Article in English | MEDLINE | ID: mdl-11379737

ABSTRACT

BACKGROUND: The natural history of congenital muscular torticollis and the outcome of different treatment modalities have been poorly investigated, and the results of treatment have varied considerably. METHODS: The main objective of this prospective study was to evaluate the outcomes of 821 consecutive patients with congenital muscular torticollis who were first seen when they were less than one year old, were treated with a standardized program of manual stretching, and were followed for a mean of 4.5 years. Before treatment, the patients were classified into one of three clinical groups: (1) palpable sternomastoid tumor, (2) muscular torticollis (thickening and tightness of the sternocleidomastoid muscle), and (3) postural torticollis (torticollis but no tightness or tumor). RESULTS: Of the 821 patients, 452 (55%) had a sternomastoid tumor; 276 (34%), muscular torticollis; and ninety-three (11%), postural torticollis. Multivariate analysis of the outcomes showed that (1) the duration of treatment was significantly associated with the clinical group (p < 0.0001), a passive rotation deficit of the neck (p < 0.0001), involvement of the right side (p < 0.0001), difficulties with the birth (p < 0.009), and age at presentation (p < 0.0001); (2) the overall final assessment score was associated with the rotation deficit (p = 0.02), age at presentation (p = 0.014), and duration of treatment (p < 0.0001); and (3) subsequent surgical treatment was required by 8% (thirty-four) of the 452 patients in the sternomastoid tumor group compared with 3% (eight) of the 276 patients in the muscular torticollis group and 0% (none) of the ninety-three patients in the postural torticollis group. CONCLUSIONS: This large prospective study demonstrated that controlled manual stretching is safe and effective in the treatment of congenital muscular torticollis when a patient is seen before the age of one year. The most important factors that predict the outcome of manual stretching are the clinical group, the initial deficit in rotation of the neck, and the age of the patient at presentation. Surgical treatment is indicated when a patient has undergone at least six months of controlled manual stretching and has residual head tilt, deficits of passive rotation and lateral bending of the neck of >15 degrees, a tight muscular band or tumor, and a poor outcome according to our special assessment chart.


Subject(s)
Manipulation, Orthopedic/methods , Torticollis/congenital , Torticollis/therapy , Age Factors , Child, Preschool , Head and Neck Neoplasms/complications , Humans , Infant , Infant, Newborn , Longitudinal Studies , Multivariate Analysis , Prospective Studies , Range of Motion, Articular , Treatment Outcome
8.
Clin Orthop Relat Res ; (384): 237-44, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11249171

ABSTRACT

Manual stretching frequently is used in the treatment of congenital muscular torticollis in infants. During manipulation, it is not uncommon for the sternocleidomastoid muscle to snap or suddenly give way. The main objective of this study was to evaluate the predisposing causes and clinical significance of such snapping. Four hundred fifty-five patients younger than 1 year of age with congenital muscular torticollis treated with a standardized gentle manual stretching program during a 13-year period were studied. Using prospective standardized assessment parameters, the pretreatment, treatment, and followup results of a group of 41 patients with snapping detected during treatment were compared with the results of a group of 404 patients without snapping during treatment. The group with snapping was associated with a more severe sternomastoid tumor, higher incidence of hip dysplasia, earlier clinical presentation, and shorter duration of treatment. With a mean followup of 3.5 years, the group with snapping was not different from the group that had no snapping in the final assessment score and percentage requiring surgery. From this study, unintentional snapping during the gentle manipulation treatment of congenital muscular torticollis has clinical and ultrasonographic evidence of partial or complete rupture of the sternocleidomastoid muscle. No long-term deleterious effect on the outcome was observed after the snapping.


Subject(s)
Neck Muscles/physiopathology , Physical Therapy Modalities , Torticollis/congenital , Torticollis/therapy , Female , Humans , Infant , Infant, Newborn , Male , Muscle Neoplasms/therapy , Prospective Studies , Sound , Torticollis/diagnosis , Torticollis/physiopathology
9.
Spine (Phila Pa 1976) ; 26(3): E19-23, 2001 Feb 01.
Article in English | MEDLINE | ID: mdl-11224874

ABSTRACT

STUDY DESIGN: Bone biopsies from iliac crest and spinous process of adolescent idiopathic scoliosis patients were obtained intraoperatively for histology and histomorphometric analysis. OBJECTIVES: To study the histologic features of cancellous bone and to correlate the histomorphometric variables with preoperative bone mineral density in patients with adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Low bone mineral density has been reported in adolescent idiopathic scoliosis. However, there is limited information about the histopathologic changes. METHODS: Undecalcified and decalcified bone specimens from iliac crest and spinous process of adolescent idiopathic scoliosis patients obtained intraoperatively were stained with Goldner and hematoxylin & eosin stain, respectively. Results were correlated with bone mineral density of the lumbar spine (L2-L4) and proximal femur measured before surgery. RESULTS: Bone histology showed significant less osteocyte count in the trabecular bone characterized with smooth and continuous borders in patients with adolescent idiopathic scoliosis. Histomorphometry confirmed the lower static parameters. The results correlated well with the decreased bone mineral density. CONCLUSION: Bone biopsy study suggested disturbance of bone turnover in patients with adolescent idiopathic scoliosis. The abnormal metabolism might contribute to the low bone mineral density and play an important role in the etiology and pathogenesis of adolescent idiopathic scoliosis.


Subject(s)
Bone Diseases, Metabolic/complications , Scoliosis/etiology , Adolescent , Adult , Age Factors , Bone Density/physiology , Bone Diseases, Metabolic/pathology , Bone Diseases, Metabolic/physiopathology , Child , Female , Femur Neck/metabolism , Femur Neck/pathology , Femur Neck/physiopathology , Humans , Ilium/metabolism , Ilium/pathology , Ilium/physiopathology , Male , Scoliosis/pathology , Scoliosis/physiopathology , Spine/metabolism , Spine/pathology , Spine/physiopathology
10.
Neuropediatrics ; 31(3): 155-8, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10963105

ABSTRACT

We present two siblings with congenital and progressive encephalopathy associated with systemic lupus erythematosus. The two brothers presented soon after birth with an encephalopathy associated with intracranial calcification (=2), intrauterine growth retardation (= 2), hepatitis (= 1) and thrombocytopenia (= 1), mimicking a congenital virus infection. Within the first year of life both children developed hypocomplementaemia and systemic lupus erythematosus (SLE), the main features of which were a discoid lupus-like rash on the hands and feet and the progressive production of high levels of autoantibodies. Both children were severely handicapped and died in early childhood from streptococcal infections. There are many causes of congenital encephalopathy with intracranial calcification. The early development of systemic lupus in these children suggested that their cerebral disease formed part of an autoimmune process. Complement levels and autoantibody profiles should be considered part of the investigation of a child with congenital infection-like syndrome, particularly when there are progressive dermatological complications.


Subject(s)
Brain Diseases/congenital , Brain Diseases/complications , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/genetics , Pneumococcal Infections/congenital , Pneumococcal Infections/complications , Antigens, CD/immunology , Autoantibodies/immunology , Brain Diseases/diagnosis , Calcinosis/complications , Calcinosis/congenital , Child, Preschool , Fatal Outcome , Humans , Infant , Lupus Erythematosus, Systemic/immunology , Male , Syndrome , Tomography, X-Ray Computed
11.
J Pediatr Surg ; 35(7): 1091-6, 2000 Jul.
Article in English | MEDLINE | ID: mdl-10917303

ABSTRACT

BACKGROUND/PURPOSE: The main objectives of this study were to define the clinical patterns and characteristics of congenital muscular torticollis (CMT) presented in the first year of life and to study the outcome of different treatment methods. METHODS: This is a prospective study of all CMT patients seen in 1 center over a 12-year period with uniform recording system, assessment methods, and treatment protocol. RESULTS: From a total of 1,086 CMT infants, 3 clinical subgroups of sternomastoid tumor (SMT; 42.7%), muscular torticollis (MT; 30.6%), and postural torticollis (POST; 22.1%) were identified. The SMT group was found to present earlier within the first 3 months and was associated with higher incidence of breech presentation (19.5%), difficult labor (56%), and hip dysplasia (6.81%). Severity of limitation of passive neck rotation range (ROTGp) was found to correlate significantly with the presence of SMT, bigger tumor size, hip dysplasia, degree of head tilt, and craniofacial asymmetry. CONCLUSIONS: A total of 24.5% of the patients with initial deficits of passive rotation of less than 10 degrees showed excellent and good outcome with active home positioning and stimulation program. The remaining cases with rotation deficits of over 10 degrees and treated with manual stretching program showed an overall excellent to good results in 91.1% with 5.1% requiring subsequent surgical treatment. The most important prognostic factors for the necessity of surgical treatment were the clinical subgroup, the ROTGp, and the age at presentation (P < .001).


Subject(s)
Torticollis/diagnosis , Torticollis/therapy , Age Factors , Female , Humans , Infant , Infant, Newborn , Male , Prospective Studies , Torticollis/congenital , Treatment Outcome
12.
J Pediatr ; 134(6): 712-6, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10356139

ABSTRACT

OBJECTIVES: Congenital muscular torticollis is a common and controversial condition in infancy. We studied prospectively a group of infants with clearly defined sternomastoid tumor treated with a well-defined protocol. STUDY DESIGN: A total of 510 cases of sternomastoid tumor in infants over a 10-year period were studied prospectively with a mean follow-up of 3.5 years and a range from 1. 5 years to 13 years. The clinical presentations, associated abnormalities, treatments, and outcomes of the overall group and subgroups were evaluated to determine the most important prognostic factors. RESULTS: The mean age of presentation was day 24, with most (92.7%) presenting before the age of 3 months. There was a high correlation with breech presentation and assisted delivery. Clinical subgroups according to the deficit in passive rotation of the neck correlated with the incidence of hip dysplasia (up to 11.6%), mode of delivery, time of presentation, degree of craniofacial asymmetry, head tilt, and the size and extent of the pseudotumor (P <.05). With an early and prolonged manual stretching program, 90.7% had excellent and good overall results. The 6.7% of patients in the poor outcome group requiring surgical treatment all belonged to the more severe rotation limitation groups. CONCLUSIONS: Subgrouping patients with sternomastoid tumor according to the passive limitation of rotation of the neck has prognostic significance, with good overall results of conservative treatment with manual stretching.


Subject(s)
Neck Muscles/physiopathology , Torticollis/congenital , Diagnosis, Differential , Female , Follow-Up Studies , Humans , Infant , Infant, Newborn , Male , Muscle Neoplasms/physiopathology , Physical Therapy Modalities , Prognosis , Risk Factors , Rotation , Torticollis/physiopathology , Torticollis/therapy
13.
Clin Orthop Relat Res ; (362): 190-200, 1999 May.
Article in English | MEDLINE | ID: mdl-10335298

ABSTRACT

Eighty-four patients with congenital muscular torticollis were treated surgically in a 10-year period with a mean followup of 5 years (range, 2-13 years). All patients were classified into subgroups according to the type of congenital torticollis, the limitation of passive rotation of the neck, and other parameters, including head tilt and craniofacial asymmetry. Twenty-two (26.2%) patients underwent surgery before they were 1 year of age, 22.6% were between 1 and 3 years of age, 38.1% were between 3 and 10 years, and 13.1% were older than 10 years. Postoperative management included physiotherapy for 3 to 4 months and the application of a multiply adjustable torticollis brace for 10 weeks in children older than 2 years of age. Loss of the sternomastoid column was found in 82.6%, poor scar in 2.4%, lateral band in 47.2% and 1.2% required a second operation. The final overall score showed excellent results in 88.1%, good results in 8.3%, and fair to poor results in 3.6%. The most important factor affecting the overall result and outcome was found to be the age of the patient at the time of operation. However, this series also showed that for patients who were 10 years or older at the time of surgery, 63.6% had excellent results and 81.8% had good to excellent results, indicating the benefit of surgery even in the late cases.


Subject(s)
Torticollis/congenital , Adolescent , Age Factors , Analysis of Variance , Braces , Child , Child, Preschool , Cicatrix/etiology , Facial Asymmetry/etiology , Female , Follow-Up Studies , Head Movements/physiology , Humans , Infant , Male , Neck Muscles/pathology , Neck Muscles/physiopathology , Physical Therapy Modalities , Postoperative Complications , Reoperation , Rotation , Torticollis/classification , Torticollis/physiopathology , Torticollis/surgery , Treatment Outcome
14.
Biochem J ; 307 ( Pt 3): 669-72, 1995 May 01.
Article in English | MEDLINE | ID: mdl-7741695

ABSTRACT

The expression of cell-surface haemopexin (Hx) receptors on human cytotrophoblasts was assessed by using four different Hx species purified from plasma: human Hx isolated by wheatgerm-affinity chromatography, human Hx isolated by haem-agarose-affinity chromatography and rabbit and rat Hx, also isolated by haem-agarose-affinity chromatography. About 3500-7000 high-affinity (Kd 0.34-0.85 nM) receptors per cell were measured by Scatchard-type analysis at 4 degrees C using human (species obtained by both methods) or rabbit 125I-labelled haem-Hx. Measured simultaneously, transferrin receptor number and affinity were 40,000/cell and 0.83 nM respectively. In contrast with transferrin receptors, the number of Hx receptors did not increase during 24 h in cytotrophoblast culture. Rat Hx showed no specific binding to human Hx receptors in cytotrophoblast cultures.


Subject(s)
Receptors, Peptide/physiology , Trophoblasts/metabolism , Trophoblasts/ultrastructure , Animals , Cells, Cultured , Female , Hemopexin/metabolism , Humans , Kinetics , Pregnancy , Rabbits , Rats , Receptors, Peptide/metabolism , Receptors, Transferrin/metabolism , Species Specificity
15.
J Pharm Pharmacol ; 45(3): 166-70, 1993 Mar.
Article in English | MEDLINE | ID: mdl-8097772

ABSTRACT

The interaction of glutathione (GSH) with coumarin, or one of a series of compounds related to coumarin, was assessed in the absence and presence of liver microsomes (direct reaction and indirect reaction, respectively) to determine the structural requirements for direct and mono-oxygenase-mediated reaction of cyclic alpha,beta-unsaturated carbonyls with GSH. Acrolein was used as a positive control for the direct reaction, and produced complete or nearly complete depletion of GSH under all assay conditions. 5,6-Dihydro-2H-pyran-2-one and 2-cyclohexen-1-one also produced substantial depletion of GSH in the direct reaction, which was not increased by the addition of liver microsomes. Coumarin, 2H-pyran-2-one and precocene I (a substituted pyran lacking the 2-one structure) were not substrates for the direct reaction but did cause depletion of GSH when incubated in the presence of rat or human liver microsomes. These depletions were dependent on a functioning mono-oxygenase system as judged by the effects of omission of cofactors, addition of competitive or inactivating inhibitors of cytochrome P450, and induction. Dihydrocoumarin, delta-valerolactone, cyclohexanone and 4H-pyran-4-one were not substrates for either the direct or indirect reaction. These findings are rationalized on the basis of a direct nucleophilic attack of GSH on the alpha,beta-centre of the alpha,beta-unsaturated carbonyl compounds, which is hindered by benzenoid resonance in coumarin and 2H-pyran-2-one, for which enzyme-mediated reaction with GSH, probably via a 3,4-epoxide, is the favoured mechanism.


Subject(s)
Coumarins/metabolism , Cytochrome P-450 Enzyme System/metabolism , Glutathione/metabolism , Aged , Animals , Coumarins/chemistry , Cytochrome P-450 Enzyme System/chemistry , Female , Glutathione/chemistry , Humans , In Vitro Techniques , Liver/enzymology , Liver/metabolism , Male , Metyrapone/pharmacology , Microsomes, Liver/drug effects , Microsomes, Liver/enzymology , Microsomes, Liver/metabolism , Rats , Rats, Wistar
16.
Biochemistry ; 14(6): 1244-50, 1975 Mar 25.
Article in English | MEDLINE | ID: mdl-804316

ABSTRACT

Tunable dye laser excitation in the intense similar to 600-nm absorption band of azurin, plastocyanin, and ceruloplasmin provides resonance enhanced Raman spectra. They consist of a complex set of bands, at least three or four in number, between 350 and 473 cm-1, which are assignable to Cu-N or Cu-O bond stretching, and a weak band near 270 cm-1, which probably arises from Cu-S stretching. A weak band at 765 cm-1 found in plastocyanin may arise from C-S stretching. Analysis of the Raman intensity pattern, as well as of the nature of the resonant electronic transition, leads to a model of the "blue" copper site involving approximately trigonal-bipyramidal coordination, with a sulfur and two nitrogen ligands in the equatorial plane, and less strongly bound nitrogen or oxygen ligands at axial positions. This arrangement would be well poised for stabilization of Cu(I) upon reduction.


Subject(s)
Azurin , Bacterial Proteins , Ceruloplasmin , Copper , Plant Proteins , Plastocyanin , Lasers , Ligands , Models, Chemical , Nitrogen , Pseudomonas aeruginosa/analysis , Scattering, Radiation , Spectrum Analysis , Sulfur
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