Adducts In Patients Research Articles

Identification of Circulating IgA Targeting Chemical Adducts in Patients with IgA Nephropathy

Identification of Circulating IgA Targeting Chemical Adducts in Patients with IgA Nephropathy

Voice outcome in medialisation thyroplasty with and without arytenoid adduction: a prospective comparison using intraoperative voice measurements

PurposeArytenoid adduction as an addition to medialisation thyroplasty is highly advocated by some surgeons in selected cases but deemed less necessary by others in patients with unilateral vocal fold paralysis. This study aims to evaluate the additional benefits on voice outcome of arytenoid adduction in patients with unilateral vocal fold paralysis undergoing medialisation thyroplasty using intra-operative voice measurements.Design/methodsA prospective study was conducted. Voice audio recordings were obtained at 4 moments; 1. direct prior to the start of surgery, 2. during surgery after medialisation thyroplasty, 3. during surgery after medialisation and arytenoid adduction, 3 months postoperative. At these same timepoints patients rated their own voice on a numeric rating scale between 0 and 10. The blinded recordings were rated by consensus in a team of experienced listeners, using the Grade of the GRBAS scale. Furthermore, the Voice Handicap Index was administered before and at 3 months after surgery.ResultsTen patients who underwent medialisation and arytenoid adduction at our tertiary referral hospital between 2021 and 2022, were included. One patient was excluded after surgery. The intraoperative measurements showed a Grade score of 1.4 preoperatively, improving to 1.2 after medialisation, 1.2 after medialisation and arytenoid adduction, and further improving to 0.4 at 3 months postoperative, which was a not statistically significant improvement (p = 0.2). The intraoperative subjective numeric rating scale showed a statistically significant improvement from 3.9 preoperatively, to 6.1 after medialisation, 7.1 after medialisation and arytenoid adduction and a 7.6 at 3 months postoperative (p = 0.001). The Voice Handicap Index total score showed a statistically significant improvement from 71 points before surgery to 13 at 3 months after surgery (p = 0.008).ConclusionsOur study using intraoperative voice measurements indicate that the addition of arytenoid adduction to medialisation thyroplasty is a benefit in selected patients although more studies are needed due to the many limitations inherent to this field of investigation.

Decrease of over-elevation in adduction after surgery of medial rectus muscles in partially refractive accommodative esotropia.

The course of over-elevation in adduction after strabismus surgery has been evaluated in a small number of research in the literature, we believe our study is the first to report the results in a specific group of esotropia (ET) patients. To report the course of postoperative over-elevation in adduction in patients who underwent surgery for horizontal deviation on the medial recti in partially accommodative ET. The medical charts of patients who had partially accommodative ET with over-elevation in adduction were reviewed retrospectively. A scale from -4 to +4 was used to grade the oblique muscle function. Among these, 17 patients who were operated solely on the horizontal rectus muscles were identified. The primary outcome measure was the degree of improvement in over-elevation in adduction after medial rectus surgery. Nine (52.9%) of the 17 patients (mean age: 5.18 ± 2.24 months) were males and 8 (47.1%) were females. The mean follow-up period was 17.06 ± 15.32 months. Overall, 15 patients (88.2%) achieved surgical success. The mean inferior oblique overaction was found 1.44 ± 0.56 preoperatively and the final postoperative mean inferior oblique overaction was 0.53 ± 0.51 (P = 0.001). Postoperative over-elevation in adduction after 3 months was significantly decreased compared to the preoperative value (P = 0.003, P = 0.001, P = 0.001 at 3rd and 6th months and final visits respectively). Over-elevation in adduction accompanying partially refractive accommodative ET seems to regress after medial rectus weakening surgery. This finding should be considered in the presurgical evaluation of these patients.

Liquid Chromatography-Mass Spectrometry Screening of Cyclophosphamide DNA Damage In Vitro and in Patients Undergoing Chemotherapy Treatment.

DNA alkylating drugs have been used as frontline medications to treat cancer for decades. Their chemical reaction with DNA leads to the blockage of DNA replication, which impacts cell replication. While this impacts rapidly dividing cancerous cells, this process is not selective and results in highly variable and often severe side effects in patients undergoing alkylating-drug based therapies. The development of biomarkers to identify patients who effectively respond with tolerable toxicities vs patients who develop serious side effects is needed. Cyclophosphamide (CPA) is a commonly used chemotherapeutic drug and lacks biomarkers to evaluate its therapeutic effect and toxicity. Upon administration, CPA is metabolically activated and converted to phosphoramide mustard and acrolein, which are responsible for its efficacy and toxicity, respectively. Previous studies have explored the detection of the major DNA adduct of CPA, the interstrand DNA-DNA cross-link G-NOR-G, finding differences in the cross-link amount between Fanconi Anemia and non-Fanconi Anemia patients undergoing chemotherapy treatment. In this study, we take advantage of our DNA adductomic approach to comprehensively profile CPA's and its metabolites' reactions with DNA in vitro and in patients undergoing CPA-based chemotherapy. This investigation led to the detection of 40 DNA adducts in vitro and 20 DNA adducts in patients treated with CPA. Moreover, acrolein-derived DNA adducts were quantified in patient samples. The results suggest that CPA-DNA damage is very complex, and an evaluation of DNA adduct profiles is necessary when evaluating the relationship between CPA-DNA damage and patient outcome.

Impact on swallowing functions of arytenoid adduction in patients with unilateral vocal fold paralysis

ObjectiveAlthough the pathophysiology of swallowing dysfunction in patients with unilateral vocal fold paralysis (UVFP) remains uncertain, glottal insufficiency is known to be a possible major cause, and other factors due to vagus nerve or recurrent laryngeal nerve damage may contribute to dysphagia or aspiration. This study aimed to evaluate the effect of arytenoid adduction (AA) surgery on the swallowing functions of UVFP patients and to investigate the important role of glottic closure during swallowing. MethodsWe prospectively analyzed the data of thirteen patients with UVFP who underwent AA in combination with medialization laryngoplasty (ML) for improving voice quality. The subjects received a series of examinations for not only voice function but also swallowing function and cough strength both preoperatively and approximately 6 months after surgery. The evaluations of voice function included the Voice Handicap Index and aerodynamic measures; the evaluations of swallowing function included the Eating Assessment Tool-10, liquid aspiration, a videofluorographic examination of swallowing study, and high-resolution manometry; and the evaluation of cough strength included the measurement of cough peak flow. All measurements before and after surgery were statistically compared and examined. ResultsConsiderable improvements in voice measures were observed after the procedure, as sufficient glottic closure was achieved during phonation and swallowing. In terms of swallowing evaluation, there were significant differences in the subjective assessment methods after the operation. Additionally, our intervention improved two cases of aspiration according to abnormal findings on the videofluorographic examination of swallowing. There was a significant difference in cough peak flow, with all participants having better values after surgery. High-resolution manometry revealed no significant differences between pre- and postsurgery in any parameters at the level of the mesopharynx or upper esophageal sphincter. ConclusionThe findings of our study suggest an important effect on the dysphagia of UVFP patients who undergo AA combined with ML. In addition, we revealed improvements in swallowing by strengthening incomplete glottic closure; thus, we consider that sufficient glottic closure must play an important role in swallowing function in patients with UVFP.

Patterns of enhancement in paretic shoulder kinematics after stroke with musical cueing

Musical cueing has been widely utilised in post-stroke motor rehabilitation; however, the kinematic evidence on the effects of musical cueing is sparse. Further, the element-specific effects of musical cueing on upper-limb movements have rarely been investigated. This study aimed to kinematically quantify the effects of no auditory, rhythmic auditory, and melodic auditory cueing on shoulder abduction, holding, and adduction in patients who had experienced hemiparetic stroke. Kinematic data were obtained using inertial measurement units embedded in wearable bands. During the holding phase, melodic auditory cueing significantly increased the minimum Euler angle and decreased the range of motion compared with the other types of cueing. Further, the root mean square error in the angle measurements was significantly smaller and the duration of movement execution was significantly shorter during the holding phase when melodic auditory cueing was provided than when the other types of cueing were used. These findings indicated the important role of melodic auditory cueing for enhancing movement positioning, variability, and endurance. This study provides the first kinematic evidence on the effects of melodic auditory cueing on kinematic enhancement, thus suggesting the potential use of pitch-related elements in psychomotor rehabilitation.

Case Report and Literature Review: Post-Arthroscopy Pneumothorax with Anterior Decompression.

IntroductionEmergency providers should recognize that pneumothorax is a rare but serious complication of shoulder arthroscopy that may require a unique approach to decompression.Case ReportWe present a case of a 60-year-old female who presented to the emergency department with right-sided facial swelling, voice change, and shortness of breath three hours after an elective arthroscopic right rotator-cuff repair and was noted to have a right-sided pneumothorax. We also describe a potential novel approach to chest tube decompression that maintains shoulder adduction in patients with recently repaired rotator cuffs.ConclusionAlthough most cases of post-arthroscopy pneumothoraces are reported in patients who received regional anesthesia or have underlying lung pathology, it can occur in lower-risk patients as was demonstrated in our case. We also suggest considering an alternative anterior approach between the midclavicular and anterior axillary lines for chest decompression in select patients when a traditional approach is less ideal due to the need to maintain shoulder immobilization postoperatively.

Mitochondrial Isolevuglandins Contribute to Vascular Oxidative Stress and Mitochondria-Targeted Scavenger of Isolevuglandins Reduces Mitochondrial Dysfunction and Hypertension.

Hypertension remains a major health problem in Western Societies, and blood pressure is poorly controlled in a third of patients despite use of multiple drugs. Mitochondrial dysfunction contributes to hypertension, and mitochondria-targeted agents can potentially improve treatment of hypertension. We have proposed that mitochondrial oxidative stress produces reactive dicarbonyl lipid peroxidation products, isolevuglandins, and that scavenging of mitochondrial isolevuglandins improves vascular function and reduces hypertension. To test this hypothesis, we have studied the accumulation of mitochondrial isolevuglandins-protein adducts in patients with essential hypertension and Ang II (angiotensin II) model of hypertension using mass spectrometry and Western blot analysis. The therapeutic potential of targeting mitochondrial isolevuglandins was tested by the novel mitochondria-targeted isolevuglandin scavenger, mito2HOBA. Mitochondrial isolevuglandins in arterioles from hypertensive patients were 250% greater than in arterioles from normotensive subjects, and ex vivo mito2HOBA treatment of arterioles from hypertensive subjects increased deacetylation of a key mitochondrial antioxidant, SOD2 (superoxide dismutase 2). In human aortic endothelial cells stimulated with Ang II plus TNF (tumor necrosis factor)-α, mito2HOBA reduced mitochondrial superoxide and cardiolipin oxidation, a specific marker of mitochondrial oxidative stress. In Ang II-infused mice, mito2HOBA diminished mitochondrial isolevuglandins-protein adducts, raised Sirt3 (sirtuin 3) mitochondrial deacetylase activity, reduced vascular superoxide, increased endothelial nitric oxide, improved endothelium-dependent relaxation, and attenuated hypertension. Mito2HOBA preserved mitochondrial respiration, protected ATP production, and reduced mitochondrial permeability pore opening in Ang II-infused mice. These data support the role of mitochondrial isolevuglandins in endothelial dysfunction and hypertension. We conclude that scavenging of mitochondrial isolevuglandins may have therapeutic potential in treatment of vascular dysfunction and hypertension.

High fractional excretion of glycation adducts is associated with subsequent early decline in renal function in type 1 diabetes

Increased protein glycation, oxidation and nitration is linked to the development of diabetic nephropathy. We reported levels of serum protein glycation, oxidation and nitration and related hydrolysis products, glycation, oxidation and nitration free adducts in patients with type 1 diabetes (T1DM) during onset of microalbuminuria (MA) from the First Joslin Kidney Study, a prospective case–control study of patients with T1DM with and without early decline in GFR. Herein we report urinary excretion of the latter analytes and related fractional excretion values, exploring the link to MA and early decline in GFR. We recruited patients with T1DM and normoalbuminuria (NA) (n = 30) or new onset MA with and without early GFR decline (n = 22 and 33, respectively) for this study. We determined urinary protein glycation, oxidation and nitration free adducts by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry (LC–MS/MS) and deduced fractional excretion using reported plasma levels and urinary and plasma creatinine estimates. We found urinary excretion of pentosidine was increased ca. twofold in patients with MA, compared to normoalbuminuria (0.0442 vs 0.0103 nmol/mg creatinine, P < 0.0001), and increased ca. threefold in patients with early decline in GFR, compared to patients with stable GFR (0.0561 vs 0.0176 nmol/mg creatinine, P < 0.01). Urinary excretion of all other analytes was unchanged between the study groups. Remarkably, fractional excretions of 6 lysine and arginine-derived glycation free adducts were higher in patients with early decline in GFR, compared to those with stable GFR. Impaired tubular reuptake of glycation free adducts by lysine and arginine transporter proteins in patients with early GFR decline is likely involved. We conclude that higher fractional excretions of glycation adducts are potential biomarkers for early GFR decline in T1DM and MA. Measurement of these analytes could provide the basis for identifying patients at risk of early decline in renal function to target and intensify renoprotective treatment.

Mass Spectrometric Characterization of Circulating Covalent Protein Adducts Derived from Epoxide Metabolites of Carbamazepine in Patients.

Carbamazepine (CBZ) is an effective antiepileptic drug that has been associated with hypersensitivity reactions. The pathogenesis of those reactions is incompletely understood but is postulated to involve a complex interplay between the drug's metabolism, genetic variation in human leukocyte antigens, and adverse activation of the immune system. Multiple T-cell activation mechanisms have been hypothesized including activation by drug-peptide conjugates derived from proteins haptenated by reactive metabolites. However, definitive evidence of the drug-protein adducts in patients has been lacking. In this study, mass spectrometry was used to characterize protein modifications by microsomally-generated metabolites of CBZ and in patients taking CBZ therapy. CBZ 10,11-epoxide (CBZE), a major electrophilic plasma metabolite of CBZ, formed adducts with glutathione-S-transferase pi (GSTP; Cys47) and human serum albumin (HSA; His146 and His338, but not Cys34) in vitro via notably divergent side-chain selectivity. Both proteins were adducted at the same residues by undefined monoxygenated metabolites ([O]CBZ) when they were incubated with human liver microsomes, NADPH and CBZ. There was also evidence for formation of a CBZ adduct at His146 and His338 of HSA derived via dehydration from an intermediate arene oxide adduct. Glutathione trapping of reactive metabolites confirmed microsomal production of CBZE and indicated simultaneous production of arene oxides. In 15 patients prescribed CBZ therapy, [O]CBZ-modified HSA (His146) was detected in all subjects. The relative amount of adduct was moderately positively correlated with plasma concentrations of CBZ (r2 = 0.44, p = 0.002) and CBZE (r2 = 0.35, p = 0.006). Our results have provided the first chemical evidence for microsomal production of [O]CBZ species that are able to escape the microsomal domain to react covalently with soluble proteins. This study has also demonstrated the presence of circulating [O]CBZ-modified HSA in patients without hypersensitivity reactions who were receiving standard CBZ therapy. The implications of those circulating adducts for susceptibility to CBZ hypersensitivity merit further immunological investigation in hypersensitive patients.

Laryngeal framework surgery: current strategies

Laryngeal framework surgery (LFS) is an indispensable surgical approach for the treatment of voice problems. The purpose of this review is to single out some relevant articles published on the topic of LFS from 2015 to mid-2016. Articles referring to injection laryngoplasty (augmentation) are entirely left aside. In the vast majority of recent publications, LFS mostly addresses surgery intended to improve vocal function in cases of glottic insufficiency. Here, medialization laryngoplasties remain the most important surgery. Arytenoid adduction remains an important technique within this field. Some clinical studies concerning indications and outcome of LFS are covered in the recent articles, trying to improve decision making for the indication of medialization laryngoplasty to enhance the rate of favorable long-term results. As in the past years, only a few articles report on laboratory research and other aspects of LFS. Articles published from 2015 to mid-2016 show that further improvements in LFS have been made, both surgically-technically and in respect of patient selection. There is still a debate about the combination of medialization laryngoplasty and arytenoid adduction in patients with unilateral vocal fold paralysis or paresis (UVFP). Although augmentation laryngoplasties are significantly increasing in number, it seems that LFS remains an important procedure within phonosurgery.

Spontaneous Regression of Over-elevation in Adduction Following Esotropia Surgery.

To evaluate the course of over-elevation in adduction in patients who had esotropia following correction of horizontal deviation. The review of the medical files identified 28 patients who had esotropia with over-elevation in adduction. Data collected from the patients' full ophthalmological examinations included visual acuity, ocular alignment, duction, versions and sensory tests for binocularity and stereopsis, cycloplegic retinoscopy, and fundus evaluation. Oblique muscle function was graded on a scale of -4 to +4. The primary outcome measure was the amount of improvement in over-elevation in adduction following esotropia surgery. Of the 28 patients (mean age: 53.5 ± 53.7 months), 13 were males and 15 were females. Of these, 22 (78.6%) had infantile esotropia and 6 (21.4%) had partial accommodative esotropia. The mean follow-up was 16.3 ± 7.9 months. All patients underwent bilateral medial rectus recession for correction of esotropia. The mean preoperative inferior oblique overaction was +2.1 ± 0.7 and the final postoperative value was +0.8 ± 0.9 (P < .001). There was a statistically significant decrease in postoperative over-elevation in adduction at all postoperative visits compared to the preoperative value (P < .001 at 3- and 6-month and final visits). Over-elevation in adduction regressed in 42 eyes (80.8%). Of these, 18 eyes (34.6%) completely resolved without any additional surgery to the inferior oblique muscle. Spontaneous regression in over-elevation in adduction was observed after esotropia surgery without additional inferior oblique weakening surgery. This may affect presurgical evaluation of and surgical planning for patients.

Vastus medialis oblique and vastus lateralis activity during a double-leg semisquat with or without hip adduction in patients with patellofemoral pain syndrome.

BackgroundThe purpose was to investigate the effect of double-leg semisquat with hip adduction on the activation of vastus medialis oblique (VMO) and vastus lateralis (VL) in patients with patellofemoral pain syndrome (PFPS).MethodsThirty patients with PFPS were designated to the study group, while 30 healthy matched subjects were enrolled in the control group. The activation of VL and VMO was recorded with surface electromyography (EMG) during double-leg semisquat (DS) and double-leg semisquat with hip adduction (DS-HA). The time domain and frequency domain indexes of the electromyography data were collected for analysis.ResultsIn the study group, the time domain indexes (RMS, IEMG) and frequency domain index (MPF) of VL were significant higher than VMO in the test of DS (P < 0.05); and the time domain of VMO was significantly higher in the test of DS-HA when compared to DS (P < 0.05) while there was no difference in the activation of VL.ConclusionsIn the study group, an increase in activity of the VMO was observed through the surface EMG signal in the double-leg semisquat exercise with hip adduction compared to the exercise without hip adduction. This finding indicates that VMO activation can be more selectively obtained through the exercise with hip adduction which can help balance the VL and VMO.

The effect of angle and moment of the hip and knee joint on iliotibial band hardness

Although several studies have described kinematic deviations such as excessive hip adduction in patients with iliotibial band (ITB) syndrome, the factors contributing to increased ITB hardness remains undetermined, owing to lack of direct in vivo measurement. The purpose of this study was to clarify the factors contributing to an increase in ITB hardness by comparing the ITB hardness between the conditions in which the angle, moment, and muscle activity of the hip and knee joint are changed. Sixteen healthy individuals performed the one-leg standing under five conditions in which the pelvic and trunk inclination were changed in the frontal plane. The shear elastic modulus in the ITB was measured as an indicator of the ITB hardness using shear wave elastography. The three-dimensional joint angle and external joint moment in the hip and knee joints, and muscle activities of the gluteus maximus, gluteus medius, tensor fasciae latae, and vastus lateralis, which anatomically connect to the ITB, were also measured. ITB hardness was significantly increased in the posture with pelvic and trunk inclination toward the contralateral side of the standing leg compared with that in all other conditions (increase of approximately 32% compared with that during normal one-leg standing). This posture increased both the hip adduction angle and external adduction moment at the hip and knee joint, although muscle activities were not increased. Our findings suggest that coexistence of an increased adduction moment at the hip and knee joints with an excessive hip adduction angle lead to an increase in ITB hardness.

Abacavir forms novel cross‐linking abacavir protein adducts in patients

Abacavir (ABC), a nucleoside-analogue reverse transcriptase inhibitor, is associated with severe hypersensitivity reactions that involve the activation of CD8+ T cells in a HLA-B*57:01-restricted manner. Recent studies have claimed that non-covalent interactions of ABC with HLA-B*57:01 are responsible for the immunological reactions associated with ABC. However, the formation of haemoglobin-ABC aldehyde (ABCA) adducts in patients exposed to ABC suggests that protein conjugation might represent a pathway for antigen formation. To further characterize protein conjugation reactions, we used mass spectrometric methods to define ABCA modifications of human serum albumin and glutathione S-transferase Pi in vitro and in patients commencing ABC therapy. ABCA formed a novel intramolecular cross-linking adduct on human serum albumin in patients and in vitro via Michael addition, followed by nucleophilic adduction of the aldehyde with a neighbouring protein nucleophile. Adducts were detected on lysine, histidine, and cysteine residues in subdomain IB of human serum albumin. Only a cysteine adduct and a putative cross-linking adduct were detected on glutathione S-transferase Pi. Modelling the docking of ABCA with HLA B*57:01 confirmed that ABCA has a strong binding affinity when bound covalently to Ser116, a key residue with regards to recognition by ABC-specific CD8+ T cells. These findings reveal that ABC forms novel types of haptens in all patients taking the drug. It is therefore vital that the immunological consequences of such haptenation pathways are explored in the in vitro models that have been used by various groups to define a new mechanism of drug hypersensitivity for ABC.

Abacavir Forms Novel Cross-Linking Abacavir Protein Adducts in Patients

Abacavir (ABC), a nucleoside-analogue reverse transcriptase inhibitor, is associated with severe hypersensitivity reactions that are thought to involve the activation of CD8+ T cells in a HLA-B*57:01-restricted manner. Recent studies have claimed that noncovalent interactions of ABC with HLA-B*57:01 are responsible for the immunological reactions associated with ABC. However, the formation of hemoglobin-ABC aldehyde (ABCA) adducts in patients exposed to ABC suggests that protein conjugation might represent a pathway for antigen formation. To further characterize protein conjugation reactions, we used mass spectrometric methods to define ABCA modifications in patients receiving ABC therapy. ABCA formed a novel intramolecular cross-linking adduct on human serum albumin (HSA) in patients and in vitro via Michael addition, followed by nucleophilic adduction of the aldehyde with a neighboring protein nucleophile. Adducts were detected on Lys159, Lys190, His146, and Cys34 residues in the subdomain IB of HSA. Only a cysteine adduct and a putative cross-linking adduct were detected on glutathione S-transferase Pi (GSTP). These findings reveal that ABC forms novel types of antigens in all patients taking the drug. It is therefore vital that the immunological consequences of such pathways of haptenation are explored in the in vitro models that have been used by various groups to define new mechanisms of drug hypersensitivity exemplified by ABC.

Covalent adduction of carbamazepine 10, 11-epoxide with human serum albumin and glutathione S-transferase pi: implications for carbamazepine hypersensitivity

BackgroundCarbamazepine (CBZ) is an effective antiepileptic drug. However, it can cause cutaneous adverse reactions in up to 10% of patients. These reactions include life-threatening conditions such as Stevens-Johnson syndrome and toxic epidermal necrolysis. It has been hypothesised that CBZ is metabolised to reactive metabolites that form haptens with cellular proteins, which are then presented by specific HLA alleles, HLA-B*1502 and HLA-A*3101, activating the immune system and triggering hypersensitivity in susceptible individuals. CBZ 10, 11-epoxide (CBZ-E) is a major circulating metabolite of CBZ and retains therapeutic activity. It is also sufficiently electrophilic to react with glutathione and proteins in vitro. However, the structures of the protein adducts were unknown. Our aim was to determine the structure of these CBZ-E protein adducts using high sensitivity proteomics tools. MethodsInitially, synthetic CBZ-E was incubated with human glutathione S-transferase pi (hGSTP) or human serum albumin (HSA). Both proteins form adducts with various reactive chemicals. Subsequently, to determine whether metabolically generated CBZ-E could also form protein adducts, CBZ was incubated with human supersomes (CYP3A4, CYP2E1, CYP2B6) and hGSTP. Tryptic peptide analysis by advanced liquid chromatography-tandem mass spectrometry was used to characterise CBZ-E adduct formation. FindingsAn adduct was identified at cys-47 of hGSTP, and adducts were identified at his146 and his338 of HSA after incubation with CBZ-E. After incubation of CBZ with human supersomes and hGSTP the dihydrohydroxy thioether adduct at cys47 of hGSTP was again identified, indicating that metabolic activation of CBZ to CBZ-E in vivo might also yield stable protein adducts. InterpretationWe have shown for the first time, to our knowledge, that CBZ-E, an abundant CBZ metabolite in man, can form covalent adducts with hGSTP and HSA in vitro. These adducts and similar adducts of other proteins could be responsible for triggering hypersensitivity reactions. Further work will focus on confirming the presence of HSA-CBZ-E adducts in patients and determining the immunogenicity of these adducts in vitro. FundingUK Medical Research Council, ICON, GlaxoSmithKline, AstraZeneca, the Medical Evaluation Unit.

Circulating levels of linoleic acid and HDL-cholesterol are major determinants of 4-hydroxynonenal protein adducts in patients with heart failure

ObjectiveMeasurements of oxidative stress biomarkers in patients with heart failure (HF) have yielded controversial results. This study aimed at testing the hypothesis that circulating levels of the lipid peroxidation product 4-hydroxynonenal bound to thiol proteins (4HNE-P) are strongly associated with those of its potential precursors, namely n-6 polyunsaturated fatty acids (PUFA). Methods and resultsCirculating levels of 4HNE-P were evaluated by gas chromatography-mass spectrometry in 71 control subjects and 61 ambulatory symptomatic HF patients along with various other clinically- and biochemically-relevant parameters, including other oxidative stress markers, and total levels of fatty acids from all classes, which reflect both free and bound to cholesterol, phospholipids and triglycerides. All HF patients had severe systolic functional impairment despite receiving optimal evidence-based therapies. Compared to controls, HF patients displayed markedly lower circulating levels of HDL- and LDL-cholesterol, which are major PUFA carriers, as well as of PUFA of the n-6 series, specifically linoleic acid (LA; P=0.001). Circulating 4HNE-P in HF patients was similar to controls, albeit multiple regression analysis revealed that LA was the only factor that was significantly associated with circulating 4HNE-P in the entire population (R2=0.086; P=0.02). In HF patients only, 4HNE-P was even more strongly associated with LA (P=0.003) and HDL-cholesterol (p<0.0002). Our results demonstrate that 4HNE-P levels, expressed relative to HDL-cholesterol, increase as HDL-cholesterol plasma levels decrease in the HF group only. ConclusionResults from this study emphasize the importance of considering changes in lipids and lipoproteins in the interpretation of measurements of lipid peroxidation products. Further studies appear warranted to explore the possibility that HDL-cholesterol particles may be a carrier of 4HNE adducts.

Cranial humerus translation, deltoid activation, adductor co-activation and rotator cuff disease — Different patterns in rotator cuff tears, subacromial impingement and controls

BackgroundArm adductor co-activation during abduction has been reported as a potential compensation mechanism for a narrow subacromial space in patients with rotator cuff dysfunction. We assessed differences in acromiohumeral distance at rest and the amount of humerus translation during active abduction and adduction in patients with rotator cuff tears (n=20) and impingement (n=30) and controls (n=10), controlled for deltoid, pectoralis major, latissimus dorsi and teres major activation (electromyography). MethodsDuring the acquirement of shoulder radiographs, subjects performed standardized isometric arm abduction and adduction tasks. EMG's were normalized between −1 and 1 using the “Activation Ratio”, where low values express (pathologic) co-activation, e.g. adductor activation during abduction. FindingsIn patients with cuff tears mean rest acromiohumeral distance was 7.6mm (SD=1.6): 3.5mm narrower compared to patients with impingement (95%-CI: 2.4–4.5) and 1.3mm narrower compared to controls (95%-CI: −0.1–2.7). Both during abduction and adduction tasks, cranial translation was observed with equal magnitudes for patients and controls, with average values of 2.3 and 1.7mm, respectively. Where patients with cuff tears had lower adductor Activation Ratios (i.e. more adductor co-activation during abduction), no association between abductor/adductor muscle activation and acromiohumeral distance was found. InterpretationThe subacromial space is narrower in patients with rotator cuff tears compared to patients with impingement and controls. We found additional subacromial narrowing during isometric abduction and, to a lesser amount, during adduction in all subjects and more adductor co-activation in patients with cuff tears. We found no association between subacromial space and activation of the deltoid and main adductors.

Effects of CYP1A1 and GSTM1 gene polymorphisms and BPDE-DNA adducts on lung cancer

To investigate the effect of CYP1A1 and GSTM1 genetic polymorphisms and BPDE-DNA adducts on lung tumorigenesis. The case control study has included 200 cases of lung cancer and 200 controls. DNA was extracted from blood samples of all subjects. The genotype of both CYP1A1 and GSTM1 were detected with PCR-based restriction fragment length polymorphisms (PCR-RELP). BPDE-DNA adducts were detected with competitive ELISA. CYP1A1 mutant genotype and GSTM1 null genotype with smoke has increased the risk of lung cancer, with OR being 2.406(1.321-4.382), 2.755(1.470-5.163), respectively. The level of BPDE-DNA adducts in patients was greater than control, and the adduct level in ever smokers was higher than never smokers, the difference was statistically significant (P= 0.0252). GSTM1 null genotype individuals with BPDE-DNA level higher than 5 adducts/10(8) nucleotide have increased risk of lung cancer (OR= 1.988, 95%CI: 1.011-3.912). Compared with never smokers with CYP1A1 wild genotype, smokers with CYP1A1 mutation genotype had an increased risk of forming a higher level of DNA adducts (P= 0.0459). Smokers with GSTM1 null genotype formed more DNA adducts compared with never smokers with GSTM1 functional genotype (OR = 2.432, 95% CI: 1.072-4.517). GSTM1 null genotype with higher level DNA adducts may increase the risk of lung cancer. DNA adducts form easier in smokers with CYP1A1 mutation genotype and GSTM1 null genotype, which in turn may influence lung tumorigenesis.