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1.
Eur Rev Med Pharmacol Sci ; 27(17): 8026-8038, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37750632

ABSTRACT

OBJECTIVE: The objective of the study was to determine the concentration of matrix metalloproteinase 9 (MMP-9) and changes in the presence of periodontopathogens in the gingival crevicular fluid before and after tooth preparation with the subgingival and equigingival finish line position. PATIENTS AND METHODS: The clinical prospective study included 20 subjects with an indication for upper canine preparation, with the subgingival (group 1) and equigingival finish line (group 2). Samples were taken in four observation intervals: 5 minutes before (control samples), as well as 15 minutes, 24 and 72 hours after tooth preparation (experimental samples). Measurement of MMP-9 was done using Enzyme-linked Immunosorbent Assay (ELISA). The presence of bacteria in the gingival fluid was proven by the Polymerase chain reaction (PCR) analysis. RESULTS: The MMP-9 values did not differ statistically significantly between the groups (p=0.524). The MMP-9 values showed a statistically significant difference in the given observation period (p<0.001) with a significant linear increase in values (p<0.001). A significant quadratic trend recorded a decrease in the MMP-9 values 15 minutes after preparation, and an increase 24 hours after preparation, without a significant difference in the interaction between groups (p=0.392). After preparation, a significant difference in the presence of periodontopathogens was confirmed, i.e., a decrease in the presence of Prevotella intermedia (p=0.025) and Tannerella forsythia (p=0.016) in group 1, and an increase in the presence of Aggregatibacter actinomycetemcomitans in both groups (p=0.029, p=0.026). CONCLUSIONS: The study is a good basis for determining the influence of tooth preparation on gingival inflammation, with therapeutic (choice of preparation technique) and preventive significance regarding the protection of the periodontal tissue from possible iatrogenic damage.


Subject(s)
Gingival Crevicular Fluid , Matrix Metalloproteinase 9 , Humans , Gingival Crevicular Fluid/metabolism , Matrix Metalloproteinase 9/analysis , Prospective Studies , Matrix Metalloproteinase 8/analysis , Matrix Metalloproteinase 8/metabolism
2.
Hippokratia ; 26(2): 62-69, 2022.
Article in English | MEDLINE | ID: mdl-37188045

ABSTRACT

BACKGROUND: Our study aimed to identify the total costs of inpatient treatment for coronavirus disease 2019 (COVID-19) in a tertiary institution in Serbia, an upper-middle-income country in Southeast Europe. METHODS: An observational, retrospective, cost-of-illness study was performed from the perspective of the National Health Insurance Fund and included a cohort of 78 females and 118 males admitted to the COVID-19 ward units of a tertiary center during the first wave of the pandemic. RESULTS: The median of the total costs in the non-survivors subgroup (n =43) was 3,279.16 Euros [interquartile range (IQR): 4,023.34; range: 355.20-9,909.61) which is higher than in the survivors (n =153) subgroup 747.10 Euros (IQR: 1,088.21; 46.71-3,265.91). The cut-off value of 156.46 Euros regarding the total costs per day was estimated to have 95.3 % sensitivity and 91.5 % specificity for predicting patients' dismal prognosis, with the area under the curve (AUC) of 0.968 (95 % confidence interval: 0.940-0.996, p <0.001). CONCLUSIONS: Direct medical inpatient treatment costs for COVID-19 represent a significant economic burden. The link between increased costs and an ultimate unfavorable outcome should be further explored.HIPPOKRATIA 2022, 26 (2):62-69.

3.
Oxid Med Cell Longev ; 2020: 5618127, 2020.
Article in English | MEDLINE | ID: mdl-33224432

ABSTRACT

The influence of milk bioactive peptides on skin regenerative potential and rejuvenation is very often limited because of allergic reactions. The current study is aimed at exploring the influence of donkey colostrum and mature milk, human colostrum and mature milk, and ß-casein and ß-casomorphine-7, on the growth and inflammatory response of the culture of cultured skin fibroblasts exposed to these conditions for twenty-four hours. Their effects on the growth-regulatory kinases and redox-sensitive, proinflammatory transcriptional factor NF-κB were detected by using specific primary antibodies against NF-κB p65, Akt-1, phospho-Akt-1, Erk-1, phospho-Erk-1, JNK, phospho-JNK, phospho-STAT-1, and CD26, while logarithmic integrated fluorescence intensity patterns were recorded by flow cytometry. The downregulation of NF-κB p65 was observed after the exposure of skin fibroblasts to donkey milk and human colostrum, while ß-casein and ß-casomorphine-7 exerted the opposite effect, which suggests that noncasein bioactive peptides of donkey and human milk may be responsible for anti-inflammatory properties. The exposure to all milk species examined and ß-casein leads to the activation of growth-regulatory kinases (Akt1/2/3 kinase, Erk kinase, JNK kinase, and Stat-1 kinase), especially for the p-Erk pathway, which suggests that essential amino acids of casein may be responsible for Erk-induced cell cycle activation and proliferation. The opposite effect was observed when cells were exposed to ß-casomorphine-7, which may affect the skin fibroblast survival and their proliferative and regenerative potential. Donkey milk did not significantly change the CD26 antigen expression. In conclusion, our results suggest that among cell signaling molecules, the most sensitive but nonspecific downstream effector is p-Erk kinase, which may point to donkey milk usefulness in wound healing, regenerative, and aesthetic dermatology. The noncasein bioactive peptides of donkey milk may be responsible for the anti-inflammatory property of donkey milk and colostrum, which may indicate the usefulness in the treatment of inflammatory skin diseases.


Subject(s)
Fibroblasts/metabolism , Milk, Human , Regeneration , Signal Transduction , Skin Physiological Phenomena , Skin/metabolism , Animals , Cell Line , Equidae , Female , Fibroblasts/pathology , Humans , Mice , Oxidation-Reduction , Skin/pathology
4.
Int J Antimicrob Agents ; 55(3): 105884, 2020 Mar.
Article in English | MEDLINE | ID: mdl-31931149

ABSTRACT

Griseofulvin is a well-known antifungal drug that was launched in 1962 by Merck & Co. for the treatment of dermatophyte infections. However, according to predictions using the Way2Drug computational drug repurposing platform, it may also have antibacterial activity. As no confirmation of this prediction was found in the published literature, this study estimated in-silico antibacterial activity for 42 griseofulvin derivatives. Antibacterial activity was predicted for 33 of the 42 compounds, which led to the conclusion that this activity might be considered as typical for this chemical series. Therefore, experimental testing of antibacterial activity was performed on a panel of Gram-positive and Gram-negative micro-organisms. Antibacterial activity was evaluated using the microdilution method detecting the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC). The tested compounds exhibited potent antibacterial activity against all the studied bacteria, with MIC and MBC values ranging from 0.0037 to 0.04 mg/mL and from 0.01 to 0.16 mg/mL, respectively. Activity was 2.5-12 times greater than that of ampicillin and 2-8 times greater than that of streptomycin, which were used as the reference drugs. Similarity analysis for all 42 compounds with the (approximately) 470,000 drug-like compounds indexed in the Clarivate Analytics Integrity database confirmed the significant novelty of the antibacterial activity for the compounds from this chemical class. Therefore, this study demonstrated that by using computer-aided prediction of biological activity spectra for a particular chemical series, it is possible to identify typical biological activities which may be used for discovery of new applications (e.g. drug repurposing).


Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Repositioning , Griseofulvin/pharmacology , Anti-Bacterial Agents/chemistry , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Bacteria/drug effects , Griseofulvin/analogs & derivatives , Humans , Microbial Sensitivity Tests
5.
Eur Ann Otorhinolaryngol Head Neck Dis ; 136(2): 123-126, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30606652

ABSTRACT

INTRODUCTION: We report a case of unilateral progressive primary hypertrophic lichen planus of the external auditory canal requiring several surgical interventions to deal with constant pruritus, otorrhoea, stenosis and conductive hearing loss. CASE SUMMARY: A 58-year-old woman was initially treated with meatoplasty for suspected chronic obliterating otitis externa. She remained symptom-free for 5 years, before the disease recurred, affecting other body surfaces as well. Otorrhoea, conductive hearing loss and pruritus worsened, and a canal wall down tympanomastoidectomy was performed, removing the skin of the external auditory canal and the tympanic membrane completely. Lichen planus was confirmed histopathologically. DISCUSSION: Very few surgical results have been published on stenosis of the external auditory canal caused by lichen planus. Complete medial external auditory canal skin elevation and removal with postoperative split-skin grafting is advised for initial treatment. We discuss treatment options and surgical outcome after initial surgical failure.


Subject(s)
Ear Canal/surgery , Ear Diseases/surgery , Lichen Planus/surgery , Disease Progression , Ear Canal/pathology , Ear Diseases/complications , Ear Diseases/pathology , Female , Hearing Loss, Conductive/etiology , Humans , Hypertrophy , Lichen Planus/complications , Lichen Planus/pathology , Mastoid/surgery , Middle Aged , Otitis Externa/surgery , Pruritus/etiology , Recurrence , Reoperation , Tympanic Membrane/surgery
6.
Doc Ophthalmol ; 136(3): 157-164, 2018 06.
Article in English | MEDLINE | ID: mdl-29779071

ABSTRACT

PURPOSE: To investigate within-test variability of the steady-state PERG (SS-PERG). METHODS: SS-PERGs were recorded in response to black-white horizontal gratings (1.6 cycles/deg, 98% contrast, 15.63 reversals/s, LED display, 25 deg square field, 800 cd/sqm mean luminance) using skin electrodes. PERG and noise (± reference) signals were averaged over 1024 epochs (~ 2.2 min) and Fourier analyzed to retrieve SS-PERG amplitude and phase. SS-PERGs were split into 16 partial averages (samples) of 64 epochs each, and corresponding amplitudes and phases combined in polar coordinates to assess their dispersion (within-test variability). To assess time-dependent variability, samples were clustered in four successive time segments of ~ 33 s each. Amplitude adaptation was defined as amplitude difference between initial and final clusters, and PERG phase adaptation as the corresponding phase difference. To determine the dynamic range of SS-PERG adaptation, recording was performed in normal controls of different age (n = 32) and patients with different severity of optic nerve dysfunction (early manifest glaucoma, EMG, n = 7; non-arteritic ischemic optic neuropathy, NAION, n = 5). RESULTS: Amplitude adaptation was largest in younger controls (amplitude adaptation ÷ noise, SNR = 9.5, 95% CI 13.1, 5.9) and progressively decreased with increasing age (older subjects, SNR = 5.5, 95% CI 9.2, 1.8) and presence of disease (EMG: SNR = 2.4, 95% CI 3.5, 1.4; NAION: SNR = 1.9, 95% CI 6.5,-2.2). In 11 young subjects, amplitude adaptation was repeatable (test-retest in two sessions a week apart; intraclass correlation coefficient = 0.59). Phase adaptation was not significantly different from zero in all groups. CONCLUSIONS: SS-PERG adaptation accounts for a sizeable portion of the within-test variability. As it has robust SNR, sufficient test-retest variability, and is altered in disease, it may have physiological and clinical significance. This study suggests that SS-PERG protocols should include adaptation in addition to SS-PERG amplitude and phase/latency.


Subject(s)
Electroretinography/methods , Glaucoma/physiopathology , Optic Neuropathy, Ischemic/physiopathology , Retinal Ganglion Cells/physiology , Adult , Aged , Electrodes , Female , Humans , Male , Middle Aged , Pattern Recognition, Visual/physiology , Young Adult
7.
Eur Rev Med Pharmacol Sci ; 21(23): 5298-5305, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29243801

ABSTRACT

Irrespective of the new generation of dental materials, acrylates still have a wide indication field. Although they are classified as biomaterials, acrylates can have both local and systemic side effects. The individual components of the acrylic materials may leave the dental restorations and diffuse into saliva. The aim of this study was to point out the potentially toxic components of acrylic dental materials, as well as their possible adverse effects on oral tissues and the organism in general. The paper was based on the assumption that the appropriate selection of the type of acrylic material and the proper method of their preparation reduce their adverse effects to a minimum, which was proven using literature data.


Subject(s)
Acrylic Resins/adverse effects , Dentures/adverse effects , Resins, Synthetic/adverse effects , Humans
8.
Hippokratia ; 20(1): 44-49, 2016.
Article in English | MEDLINE | ID: mdl-27895442

ABSTRACT

BACKGROUND: Medical Fear Survey (MFS) is an instrument designed for measuring fear of medical and related treatments. OBJECTIVE: Aim of the present study was MFS translation into Serbian, measurement of its psychometric properties and MFS validation using other Blood-injury-injections and related stimuli instruments that have been translated from English into Serbian. METHOD: After obtaining permission from the author of the original MFS, double forward translation from English to Serbian and backward translation to English were conducted in ten steps, according to International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines. Reliability, factorial analysis and concurrent validation of Serbian version of MFS were conducted on a sample of 485 medical or pharmacy students at University of Kragujevac, Serbia. RESULTS: Serbian version of MFS showed high internal consistency with a Cronbach's alpha 0.968 and good temporal stability after testing-and-retesting (Spearman's correlation coefficient 0.838, and intraclass correlation coefficient 0.877). Factorial analysis confirmed the same five factors demonstrated in the original English version: fear of mutilated bodies (10 items), fear of blood (11 items), fear of injections and blood draws (9 items), fear of sharp objects (10 items), and fear of medical examinations and physical symptoms (10 items). The total score of MFS correlated significantly with the total scores of Injection Phobia Scale-Anxiety (Spearman's correlation coefficient 0.391, p <0.001), Blood/Injection Fear Scale (Spearman's correlation coefficient 0.502, p <0.001) and Medical Avoidance Survey (Spearman's correlation coefficient 0.396, p <0.001). CONCLUSIONS: Serbian version of the 50-item MFS showed similar psychometric properties as the original English version of this scale, with the same factorial structure. It could be used for measurement of fear of medical and related treatments in Serbian socio-cultural milieu, preferably self-administered. Hippokratia 2016, 20(1): 44-49.

10.
West Indian Med J ; 65(2): 375-378, 2016 Feb 09.
Article in English | MEDLINE | ID: mdl-28358450

ABSTRACT

OBJECTIVE: Geriatric dentistry refers to dealing with oral diseases including prevention and treatment in old individuals. The aim of this investigation was to examine the types and frequency of oral lesions in the elderly. SUBJECTS AND METHODS: The study involved 75 elderly persons. The clinical diagnosis was established by correlating the aetiological factor associated with the lesion and by systematic examination of the oral mucosa and classifying those alterations according to the epidemiological guidelines for the diagnosis of oral mucosal diseases. During the clinical examination, the following elements were analysed: features of the lesion, anatomical location, extension, aetiological factors or related factors, dental status, alcohol, tobacco, trauma, use of prosthesis and if such were well adapted. RESULTS: Sixty lesions were diagnosed in 75 patients. These were classified according to clinical, histopathological and microbiological diagnosis and were distributed into 15 different clinical entities. The more prevalent pathologies were inflammatory, reactive and associated with long-term use of prostheses or ill-adapted prostheses, since 67% of the patients with lesions were using prostheses. Of the lesions related to prosthesis use, denture stomatitis was the most common one, representing 20 cases (33.3%). The second most frequent lesion was erythematous candidiasis (10%). The other most frequent lesions in this study were lingua plicata, xerostomia and pseudomembranous candidiasis. CONCLUSION: Oral and perioral tissues undergo different functional and structural changes with ageing. The role of the dentist and stomatologist includes the management of systemic, nutritional and pharmacological oral manifestations in order to establish an early diagnosis and subsequent accurate treatment.

11.
Folia Morphol (Warsz) ; 75(2): 188-195, 2016.
Article in English | MEDLINE | ID: mdl-26711645

ABSTRACT

The aim of the present study was to assess the influence of quercetine (QE) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Wistar albino rats were divided into three groups: sham-operated (SH), PH and PH+QE; each group contain 8 animals. The rats in QE-treated groups were given QE (15 mg/kg body weight) once a day i.p., for 7 days starting 3 days prior to hepatectomy operation. At 7 days after resection, liver samples were collected. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labelling, proliferation index (PI), transferase-mediated dUTP nick end-labelling assay, apoptotic index (AI) were evaluated at 7 days after hepatectomy. As a result, QE significantly increased MI, PI, and significantly decreased AI in PH rats. Additionally, QE remarkably inhibited the elevation of MDA, restored impaired antioxidant SOD activity and GSH level, and also attenuated hepatic vacuolar degeneration and sinusoidal congestion. These results suggested that QE treatment had a beneficial effect on liver regenerative capacity of the remnant liver tissue after hepatectomy, probably due to its antioxidative, antiapoptotic and proliferative property.


Subject(s)
Liver Regeneration , Animals , Hepatectomy , Liver , Male , Oxidative Stress , Quercetin , Rats , Rats, Wistar
12.
Stomatologiia (Mosk) ; 93(1): 46-9, 2014.
Article in Russian | MEDLINE | ID: mdl-24576970

ABSTRACT

The paper presents clinical case of 63 years old edentulous patient with slight class III malocclusion. For 15 years he was using inadequately fabricated dentures causing forced severe class III malocclusion. Forced progeny was corrected by newly fabricated dentures which restored normal orofacial function and facial harmony.


Subject(s)
Dental Prosthesis Design , Denture, Partial, Removable , Malocclusion, Angle Class III/etiology , Malocclusion, Angle Class III/rehabilitation , Tooth Loss/complications , Humans , Male , Middle Aged , Models, Dental
13.
Scand J Immunol ; 79(3): 181-6, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24383677

ABSTRACT

Immunoinflammatory-mediated demyelination, the main pathological feature of multiple sclerosis (MS), is regularly accompanied by neurodegenerative processes, mostly in the form of axonal degeneration, which could be initiated by glutamate excitotoxicity. In the current study, the relationship between Th17-mediated inflammatory and excitotoxic events was investigated during an active phase of MS. Cerebrospinal fluid (CSF) of patients with MS and control subjects was collected, and IL-17A and glutamate levels were determined. IL-17A level was significantly higher in patients with MS; whereas no statistically significant changes in glutamate concentrations were found. There was a direct correlation between IL-17A and glutamate levels; IL-17A levels were also associated with the neutrophil expansion in CSF and blood-brain barrier disruption. However, IL-17A level and the number of neutrophils tended to fall with disease duration. The results suggest that Th17 cells might enhance and use glutamate excitotoxicity as an effector mechanism in the MS pathogenesis. Furthermore, Th17 immune response, as well as neutrophils, could be more important for MS onset rather than further disease development and progression, what could explain why some MS clinical trials, targeting Th17 cells in the later stage of the disease, failed to provide any clinical benefit.


Subject(s)
Glutamic Acid/cerebrospinal fluid , Interleukin-17/cerebrospinal fluid , Multiple Sclerosis/cerebrospinal fluid , Th17 Cells/immunology , Adolescent , Adult , Aged , Blood-Brain Barrier/immunology , Female , Glutamic Acid/metabolism , Humans , Inflammation/immunology , Interleukin-17/metabolism , Male , Middle Aged , Multiple Sclerosis/metabolism , Multiple Sclerosis/pathology , Neutrophils/immunology , Young Adult
14.
Am J Transplant ; 13(8): 2066-74, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23718940

ABSTRACT

We aimed to provide an overview of kidney allocation policies related to children and pediatric kidney transplantation (KTx) practices and rates in Europe, and to study factors associated with KTx rates. A survey was distributed among renal registry representatives in 38 European countries. Additional data were obtained from the ESPN/ERA-EDTA and ERA-EDTA registries. Thirty-two countries (84%) responded. The median incidence rate of pediatric KTx was 5.7 (range 0-13.5) per million children (pmc). A median proportion of 17% (interquartile range 2-29) of KTx was performed preemptively, while the median proportion of living donor KTx was 43% (interquartile range 10-52). The median percentage of children on renal replacement therapy (RRT) with a functioning graft was 62%. The level of pediatric prioritization was associated with a decreased waiting time for deceased donor KTx, an increased pediatric KTx rate, and a lower proportion of living donor KTx. The rates of pediatric KTx, distribution of donor source and time on waiting list vary considerably between European countries. The lack of harmonization in kidney allocation to children raises medical and ethical issues. Harmonization of pediatric allocation policies should be prioritized.


Subject(s)
Government Regulation , Kidney Failure, Chronic/therapy , Kidney Transplantation/statistics & numerical data , Kidney Transplantation/trends , Patient Selection , Practice Patterns, Physicians' , Adolescent , Adult , Child , Eligibility Determination , Europe , Female , Graft Rejection , Graft Survival , Health Care Rationing/legislation & jurisprudence , Humans , Kidney Failure, Chronic/mortality , Kidney Transplantation/legislation & jurisprudence , Male , Registries , Survival Rate , Tissue Donors/statistics & numerical data , Waiting Lists , Young Adult
17.
Stomatologiia (Mosk) ; 88(1): 58-60, 2009.
Article in Russian | MEDLINE | ID: mdl-19365350

ABSTRACT

A layer of desensitizing agent for prepared teeth was applied to tooth stump prior to the final cementation of cast crowns in order to alleviate postoperative sensibility. The aim of the study was to establish under in vitro conditions whether the application of the suspension of calcium hydroxide (Kaviner) on prepared teeth decreased the cast crown bonding strength. 40 intact human premolars were extracted for orthodontic reasons and prepared by high capacity machine using water supply cooling. Experimental crowns were made by a standard procedure using NiCrMo alloy and cemented by zinc phosphate or glass ionomer luting cements (20 in each group). Bond strength between prepared teeth and crowns was mechanically tested by using electronic dynamometer, at first without suspension of calcium hydroxide and then after its application. The results obtained pointed to decrease of bonding strength with both used luting cements: decrease of retention force with zinc phosphate cement was equal to 1.9% and with glass ionomer cement - 4.2%. However, the retention forces values obtained after the application of Kaviner for both dental cements observed were still clinically acceptable.


Subject(s)
Analgesics, Non-Narcotic/chemistry , Calcium Hydroxide/chemistry , Crowns , Dental Cements/chemistry , Dental Prosthesis Retention , Dentin/drug effects , Analgesics, Non-Narcotic/pharmacology , Calcium Hydroxide/pharmacology , Chromium Alloys/chemistry , Dental Cements/pharmacology , Dentin/chemistry , Humans
18.
Acta Chir Iugosl ; 55(1): 47-53, 2008.
Article in English | MEDLINE | ID: mdl-18510061

ABSTRACT

Gastroesophageal reflux disease (GERD) is the most common esophageal disorder and the most frequent reason why infants are referred to the pediatric gastroenterologist, affecting as much as 30% of the pediatric population. Presenting features of GERD in infants and children are quite variable and follow patterns of gastrointestinal and extra-esophageal manifestations that vary between individual patients and may change according to age. Patients may be minimally symptomatic, or may exhibit severe esophagitis, bleeding, nutritional failure, or severe respiratory problems. GERD is also complex for the diagnostic techniques required to assess its repercussions or explain its origin. Although different abnormalities in motility variables, such as lower eso-phageal sphincter (LES) function, esophageal peristalsis and gastric motor activity can contribute to the development of GERD, the degree of esophageal acid exposure represents the key factor in its pathogenesis. Esophageal pH monitoring, based on both the detection of acid reflux episodes and the measurement of their frequency and duration, has been regarded as the most sensitive and specific diagnostic tool for diagnosing reflux disease. The aim of this paper is to give a concise review for the clinicians encountering this specific disease in infants and children.


Subject(s)
Gastroesophageal Reflux , Child , Gastroesophageal Reflux/diagnosis , Gastroesophageal Reflux/physiopathology , Gastroesophageal Reflux/therapy , Humans , Infant
19.
J Toxicol Clin Toxicol ; 41(6): 793-800, 2003.
Article in English | MEDLINE | ID: mdl-14677789

ABSTRACT

INTRODUCTION: Treatment thresholds for methanol poisoning are based on case reports and published opinion. Most guidelines recommend treatment for a methanol level > or = 20 mg/dL in a nonacidotic patient. No supportive data have been offered nor has the time of the exposure been addressed. For instance, no distinction has been drawn between a methanol level drawn 1 hr vs. 24 hr from ingestion. We analyzed all published cases of methanol poisoning to determine the applicability of the 20 mg/dL threshold in a nonacidotic patient, specifically those arriving early for care (within 6 hr) with a peak or near-peak blood methanol concentration. METHODS: Using predefined search criteria, a systematic review of the world literature was performed using MEDLINE and EMBASE. In addition, each article's references were hand searched for pre-1966 articles, as were fatality abstracts from all U.S. poison centers. Human cases were included if they reported a known time of a single methanol exposure, acid-base data, blood methanol, and blood ethanol (if not acidotic). RESULTS: Dating to 1879, 372 articles in 18 languages were abstracted using a standard format; 329 articles (2433 patients) involved methanol poisoning, and 70 articles (173 patients) met inclusion criteria. Only 22 of these patients presented for care within 6hr of ingestion with an early methanol level. All but 1 patient was treated with an inhibitor of alcohol dehydrogenase (ADH). A clear acidosis developed only with a methanol level > or = 126 mg/dL. The patient that did not receive an ADH inhibitor was an infant with an elevated early methanol level (46 mg/dL) that was given folate alone and never became acidotic. Intra and inter-rater reliability were 0.95. CONCLUSIONS: Nearly all reports of methanol poisoning involve acidotic patients far removed from ingestion. The small amount of data regarding patients arriving early show that 126 mg/dL is the lowest early blood methanol level ever clearly associated with acidosis. Contrary to conventional teaching, there are case reports of acidosis after only a few hours of ingestion. The data are insufficient to apply 20 mg/dL as a treatment threshold in a nonacidotic patient arriving early for care. Prospective studies are necessary to determine if such patients may be managed without antidotal therapy or dialysis.


Subject(s)
Methanol/toxicity , Acidosis/chemically induced , Acidosis/metabolism , Adolescent , Adult , Antidotes/therapeutic use , Bicarbonates/blood , Child, Preschool , Dose-Response Relationship, Drug , Female , Fomepizole , Humans , Male , Methanol/blood , Methanol/pharmacokinetics , Middle Aged , Pyrazoles/therapeutic use , Treatment Outcome
20.
Biochemistry ; 40(19): 5602-14, 2001 May 15.
Article in English | MEDLINE | ID: mdl-11341825

ABSTRACT

Putidaredoxin (Pdx), a Cys4Fe2S2 ferredoxin from Pseudomonas putida, exhibits redox-dependent binding to its physiological redox partner, cytochrome P450(cam) (CYP101), with the reduced form of Pdx (Pdx(r)) binding with greater affinity to oxidized camphor-bound CYP101 than the oxidized form, Pdx(o). It has been previously shown that Pdx(o) is more dynamic than Pdx(r) on all accessible time scales, and it has been proposed that Pdx(r) samples only a fraction of the conformational substates populated by Pdx(o) on a time average. It is postulated that the ensemble subset populated by Pdx(r) is the same subset that binds CYP101, providing a mechanism for coupling the Pdx oxidation state to binding affinity for CYP101. Evidence from a variety of sources, including redox-dependent shifts of 15N and 13C resonances, indicates that the metal cluster binding loop of Pdx is the primary determinant of redox-dependent conformational selection. Patterns of paramagnetic effects suggest that the metal cluster binding loop contracts around the metal cluster upon reduction, possibly due to the strengthening of hydrogen bonds between the sulfur atoms of the metal cluster and the surrounding polypeptide NH and OH groups. Effects of this perturbation are then transmitted mechanically to other affected regions of the protein. A specific mutation has been introduced into the metal binding loop of Pdx, G40N, that slows conformational exchange sufficiently that the ensemble of conformational substates in Pdx(o) are directly observable as severe broadenings or splittings in affected NMR resonances. Many of the residues most affected by the mutation also show significant exchange contributions to 15N T(2) relaxation in wild-type Pdx(o). As predicted, G40N Pdx(r) shows a collapse of many of these multiplets and broadened lines to form much sharper resonances that are essentially identical to those observed in wild-type Pdx(r), indicating that Pdx(r) occupies fewer conformational substates than does Pdx(o). This is the first direct observation of such redox-dependent ensembles at slow exchange on the chemical shift time scale. These results confirm that conformational selection within the Fe2S2 cluster binding loop is the primary source of redox-dependent changes in protein dynamics in Pdx.


Subject(s)
Cysteine/chemistry , Ferredoxins/chemistry , Amino Acid Sequence , Asparagine/genetics , Carbon Isotopes , Ferredoxins/genetics , Glycine/genetics , Iron/chemistry , Molecular Sequence Data , Mutagenesis, Site-Directed , Nitrogen Isotopes , Nuclear Magnetic Resonance, Biomolecular , Oxidation-Reduction , Peptide Mapping , Protein Conformation , Protons , Pseudomonas putida/genetics , Spectrophotometry, Ultraviolet , Sulfur/chemistry , Thermodynamics
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