Benefits and risks of using bacterial- and plant-produced nano-silver for Japanese quail hatching-egg sanitation.

This research compared how bacterial-, plant-produced silver nanoparticles (Ag-NPs) and TH4 affected the eggshells microbial load and quail chicks' liver structure, embryonic mortality, and features related to hatchability. Ag-NPs were sensitized by bacterial and plant methods, and then identified by UV-visible spectroscopy, TEM, and FTIR spectroscopy. B-Ag-NPs were found in spherical shapes in size ranging from 7.09 to 18.1 nm versus multi-shape with size range of 25.0-78.1 nm for P-Ag-NPs. A total number of 624 eggs (in three equal groups) of Japanese quail flock were sprayed with TH4 as control, B-Ag-NPs and P-Ag-NPs. Thereafter, three eggs were sampled randomly from each group for determining important microbial groups. The remaining eggs were incubated according to the recommended incubation conditions. On the day of hatching, the percentages of hatchability and embryonic mortality were measured. Besides, five chicks from each treatment were slaughtered and the livers were utilized for ICP and histological tests. The effects of all three treatments on the microbial count in eggshells were comparable, according to the results. In addition, there was no negative effect on either hatchability percentage or embryonic mortality rate. The liver structure from both B-Ag-NPs and P-Ag-NPs treatments exhibited severe and moderate degeneration of hepatocytes, which may indicate possible hazardous effects of using nanoparticles. Using TH4 did not cause liver structure abnormality. In conclusion, using Ag-NPs for sanitizing hatching eggs effectively reduces the eggshell microbial count without affecting the hatchability percentage. Nevertheless, histological changes are appropriate to be considered as a safety parameter in Ag-NPs applications.

Fungal keratitis due to Scopulariopsis brevicaulis and a potential promising therapeutic effect of antibacterial agents: A case report.

INTRODUCTION: Microbial keratitis is a serious potentially blinding corneal infection. Contact lens wear remains the most common predisposing factor. Fungal keratitis represent only a small fraction of the overall number of cases of contact lens-associated microbial keratitis, however they are proportionally more severe. PATIENT CONCERNS: An 18-year-old female, who occasionally used eye cosmetic soft contact lenses, presented with pain, redness, and blurring of vision in her left eye. DIAGNOSIS: The left eye showed decreased visual acuity, central corneal ulcer and abscess, and severe ciliary injection. A provisional diagnosis of infectious keratitis was considered. INTERVENTION: Corneal scrapings were aseptically collected and directly inoculated onto sterile bacterial and fungal agar plates that were immediately incubated. The patient was admitted and started on topical and systemic antibacterial agents. OUTCOMES: The infection showed signs of satisfactory clinical resolution. However, the mold Scopulariopsis brevicaulis was isolated in pure colonies 5 days after presentation. CONCLUSION: We report the first case from Jordan of fungal keratitis caused by the mold S brevicaulis. A high index of suspicion is required for fungal keratitis caused by S brevicaulis in immunocompetent patients who wear contact lenses despite its rarity. This fungal infection was successfully treated using antibacterial agents. However, larger studies are recommended to investigate the clinical effectiveness of antimicrobial agents that have both antibacterial and antifungal effects and to assess their role as empirical therapeutic modalities for infectious keratitis.

Awareness of pharmacy researchers about the national research code of ethics: A study from Jordan.

OBJECTIVE: In Jordan, research ethics have been subject to increasingly formal regulations and structuring. Recently the Ministry of Higher Education and Research Published the National Research Code of Ethics. However, little is known about the awareness of pharmacology researchers of this code and the extent of its applicability to their research. METHODS: Purposeful sampling through institutions' websites was used to identify staff members with excellent profiles from 20 Faculties of Pharmacy in Jordan. After obtaining the required approvals, in-depth interviews were conducted, recorded, transcribed, and analyzed using NVivo 11 Software. The interviews followed a previously prepared and validated interview guide that covered various aspects of education, research, and training. KEY FINDINGS: Eighteen members of staff agreed to take part in the study. Qualitative analysis revealed three main themes each concerning respondents' awareness of the National Code of Research Ethics in Jordan. The emerging themes were: the lack of awareness regarding the code of ethics, the need for clear guidelines for pharmacology research in Jordan, and the need for further workshops and training courses for pharmacology researchers. CONCLUSION: This study highlights a lack of awareness regarding the presence of the National Research Ethics Code among pharmacology researchers in Jordan. This might have negative implications on medical research. It was thought that the code of ethics should be incorporated in postgraduate pharmacy education, training courses for pharmacy researchers, and workshops for pharmacy academic staff.

Caesarean section delivery from maternal perspective: An exploratory study in Jordan.

AIMS OF THE STUDY: This study aims to determine females' views, experiences and attitudes regarding the caesarean section (CS) and to explore the factors that increase the prevalence of CS in Jordan. DESIGN: This is a cross-sectional study using a questionnaire that was distributed electronically through social media websites. Study participants included 1005 females with a history of at least one CS. Awareness, experiences about CS, complications and reasons for performing CS were investigated. SETTINGS: The participants were recruited from all Jordan cities by social media and emails. FINDINGS: Most of the respondents stated that the source of their knowledge about CS was from the internet (36.2%) followed by family and friends (31.6%). The majority of respondents were satisfied with their CS experience (72.8%). More than half of the participants (56.9%) reported that CS carries no risk for infants. About 53% of respondents stated that the most common reason leading women to choose to give birth via CS is the fear of labour pain. However, the majority of the respondents disagree with performing CS under maternal request (59.2%). CONCLUSIONS AND IMPLICATIONS: This study indicated that Jordanian females do not have reliable sources of information about CS. This leads to lower awareness of CS and its complications, and, as expected, CS is more likely to be performed by privately insured women.

Influence of CYP4F2, ApoE, and CYP2A6 gene polymorphisms on the variability of Warfarin dosage requirements and susceptibility to cardiovascular disease in Jordan.

Cardiovascular diseases are among the leading causes of death worldwide. Many of those diseases require treatment with warfarin, an anticoagulant that has a large high inter and intra-variability in the required doses. The aim of this study is to find if there are any associations between rs2108622 of CYP4F2, rs7412 and rs405509 of ApoE, and rs1801272 of CYP2A6, and CVD and warfarin dose variability. The selected genes and their polymorphisms are involved in many GWAS associated with cardiovascular disease and variability in warfarin treatment. The study sample consisted of 212 Jordanian Cardiovascular patients and 213 healthy controls. DNA was extracted and the Mass ARRAY™ system was used to genotype four selected SNPs within three genes (CYP4F2, ApoE, and CYP2A6). Only one out of the four selected SNPs (ApoE rs7412 SNP) was found to be associated with the risk of cardiovascular disease. Also, this SNP showed significant differences in warfarin initial doses. CYP2A6 rs1801272 SNP was found to be associated with warfarin sensitivity during the initiation phase of therapy and with warfarin responsiveness and INR measurement during the stabilization phase of therapy. This study improves the current understanding of the high inter and intra-variabilities in response to warfarin, including the variety of dosing requirements and the susceptibility to cardiovascular disease in the Jordanian Arab population. Further study on a larger sample and in different ethnic groups could help in improving our understanding of warfarin's pharmacogenetics and its application in personalized medicine.

Impact of PCSK9, WDR12, CDKN2A, and CXCL12 Polymorphisms in Jordanian Cardiovascular Patients on Warfarin Responsiveness and Sensitivity.

BACKGROUND: The main objective of this study is sought to determine the impacts of PCSK9, WDR12, CDKN2A, and CXCL12 polymorphisms on warfarin sensitivity and responsiveness in Jordanian cardiovascular patients during the initiation and stabilization phases of therapy. METHODS: This study took place at the anticoagulation clinic at Queen Alia Heart Institute (QAHI) in Jordan. DNA samples were collected from 212 cardiovascular patients and 213 healthy controls. Genomic SNPs genotyping was conducted using the MassARRAY System at the Australian Genome Research Facility. RESULTS: This study assessed 10 polymorphisms (rs11206510 within the PCSK9 gene, rs6725887 and rs7582720 within the WDR12 gene, rs4977574, rs10757278, and rs1333049 within the CDKN2A gene, rs2862116, rs7906426, rs1746048, and rs268322 within the CXCL12 gene) in 212 Jordanian cardiovascular patients. Carriers of CDKN2A rs1333049, rs10757278, and PCSK9 rs11206510 polymorphisms had an increased risk of resistance during the initiation phase of warfarin therapy compared to those who do not carry it, or those who are carrying one polymorphism only (P < 0.05), while carriers of CXCL12 rs7906426 polymorphism had similar increased risk but during the stabilization phase of warfarin therapy (P < 0.05). CONCLUSION: Carriers of CXCL12 rs2862116 polymorphism had an increased risk to be warfarin extensive responders compared to those with no or only one polymorphism (P = 0.01). However, the presence of PCSK9 rs11206510 polymorphism affects the warfarin maintenance doses (P ˃ 0.0001).

Knowledge, Attitude, Behavior, and Stress Related to COVID-19 among Undergraduate Health Care Students in Jordan.

OBJECTIVES: This study aimed to assess knowledge, attitude, and infection control measures related to the coronavirus disease 2019 (COVID-19) pandemic outbreak among Jordanian health care students. Besides, their social behavior and stress level regarding COVID-19 infection were assessed. MATERIALS AND METHODS: An online questionnaire was distributed to medical, dental, pharmacy, nursing, and applied health science students in Jordan during the COVID-19 outbreak quarantine in March 2020. The questionnaire comprised 38 questions assessing demographic data, knowledge, attitude, risk perception, and stress level toward COVID-19. Questions regarding infection control measures and social behavior after the quarantine were also included. STATISTICAL ANALYSIS: Independent samples t-test, one-way analysis of variance (ANOVA), and chi-square at a significance level of 5% were used for data analysis. RESULTS: A total number of 935 responses were collected. The knowledge score of 55.72% of participants was satisfactory and it was higher for the clinical years' students compared with the basic years' students (p = 0.000) (descending order: sixth year > fifth year > fourth year > third year > first year > second year). Also, knowledge scores were significantly higher for medical and dental students than other disciplines (descending order: medicine, dentistry, pharmacy, nursing/applied) (p = 0.000). The social media (89.1%) and TV or radio (69.5%) were mainly routes through which participants heard about COVID-19. Moderate and justifiable feelings about COVID-19 were found in the majority of the participants. CONCLUSION: Although the majority of students showed good knowledge scores, few of them appeared to have a serious lack of knowledge. Therefore, proper education and mentoring are necessary for students before reopening the university campuses.

WITHDRAWN: Evaluation of the factors that may contribute to the responsiveness of anti-epileptic treatments in pediatric patients, a study from Jordan.

This article has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the publication of this paper, which had been rejected by the editor. This error bears no reflection on the editor. The publisher apologizes to the authors, editor and the readers for this unfortunate error. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Predictors of Cardiovascular Autonomic Neuropathy Onset and Progression in a Cohort of Type 1 Diabetic Patients.

AIM: The prevalence of cardiovascular autonomic neuropathy (CAN) in diabetes mellitus is well documented. However, the rate and predictors of both the development and progression of CAN have been less studied. Hereby, we assessed the rate and the major risk factors for CAN initiation and progression in a cohort of type 1 diabetic patients followed over a three-year period. METHODS: 175 type 1 diabetic patients (mean age: 50 ± 11 years; female/male: 76/99) with positive bedside screening for CAN were included and underwent 2 standardized autonomic testings using 4 standardized tests (deep breathing, Valsalva maneuver, 30/15 ratio, and changes in blood pressure during standing), separated by 3 ± 1 years. CAN staging was achieved according to the Toronto Consensus Panel on Diabetic Autonomic Neuropathy into 4 categories: absent, possible, confirmed, or severe CAN. RESULTS: Out of the 175 patients included, 31.4% were free of CAN, 34.2% had possible CAN, 24.6% had confirmed CAN, and 9.7% exhibited severe CAN at the first assessment. Among the 103 patients with nonsevere CAN at inclusion, forty-one (39.8%) had an increase of at least one category when reassessed and 62 (60.2%) remained stable. A bivariate analysis indicated that only BMI and exposure to selective serotonin reuptake inhibitors (SSRIs) were significantly different in both groups. A multivariate analysis indicated that lower BMI (OR: 0.15, CI 95%: 0.05-0.48, p = 0.003) and SSRI exposure (OR: 4.18, CI 95%: 1.03-16.97, p = 0.04) were the sole predictors of CAN deterioration. In the 55 patients negative for CAN at the first laboratory assessment, 12 became positive at the second assessment. CONCLUSION: No clear predictive factor for CAN onset was identified. However, once present, CAN progression was related to low BMI and SSRI exposure.

TIPIC Syndrome: Beyond the Myth of Carotidynia, a New Distinct Unclassified Entity.

BACKGROUND AND PURPOSE: The differential diagnosis of acute cervical pain includes nonvascular and vascular causes such as carotid dissection, carotid occlusion, or vasculitis. However, some patients present with unclassified vascular and perivascular changes on imaging previously reported as carotidynia. The aim of our study was to improve the description of this as yet unclassified clinico-radiologic entity. MATERIALS AND METHODS: From January 2009 through April 2016, 47 patients from 10 centers presenting with acute neck pain or tenderness and at least 1 cervical image showing unclassified carotid abnormalities were included. We conducted a systematic, retrospective study of their medical charts and diagnostic and follow-up imaging. Two neuroradiologists independently analyzed the blinded image datasets. RESULTS: The median patient age was 48 years. All patients presented with acute neck pain, and 8 presented with transient neurologic symptoms. Imaging showed an eccentric pericarotidian infiltration in all patients. An intimal soft plaque was noted in 16 patients, and a mild luminal narrowing was noted in 16 patients. Interreader reproducibility was excellent. All patients had complete pain resolution within a median of 13 days. At 3-month follow-up, imaging showed complete disappearance of vascular abnormalities in 8 patients, and a marked decrease in all others. CONCLUSIONS: Our study improved the description of an unclassified, clinico-radiologic entity, which could be described by the proposed acronym: TransIent Perivascular Inflammation of the Carotid artery (TIPIC) syndrome.

Non-obstructive carotid atherosclerosis and patent foramen ovale in young adults with cryptogenic stroke.

BACKGROUND AND PURPOSE: Up to 50% of ischaemic strokes in young adults are classified as cryptogenic despite extensive work-up. We sought to evaluate the prevalence of non-obstructive carotid atherosclerosis (NOCA) and its association with patent foramen ovale (PFO) in young adults with cryptogenic stroke (CS). METHODS: Patients aged 18-54 years, consecutively treated for first-ever CS in an academic stroke service, were included. NOCA was assessed using carotid ultrasound examination and was defined as carotid plaque with <50% stenosis. PFO was diagnosed with transesophageal echocardiography. RESULTS: A total of 164 patients [mean age (SD) = 43.7 (8.5) years; 104 men] were included. A PFO was found in 79/164 (48.2%) patients. NOCA was demonstrated in 41/164 (25%) patients. NOCA was more common in patients without PFO [37.6% vs. 11.4%, P < 0.001; adjusted odds ratio (95% confidence interval), 0.24 (0.10-0.56)]. Older age (P = 0.046) and subcortical location of cerebral infarct (P = 0.015) were also associated with the absence of PFO, whereas hypertension, diabetes and smoking were not. CONCLUSIONS: This study demonstrates that NOCA is common in young adults with CS. NOCA is negatively associated with PFO. Detecting NOCA is an important component of stroke investigation in young adults.

A potential mechanism associated with lead-induced testicular toxicity in rats.

This study was conducted to investigate the mechanism of lead (Pb)-induced testicular toxicity. We examined the impact of Pb toxicity on 17ß-oestradiol (E2), oestrogen receptors (ERs) and aromatase P450 which are key factors in spermatogenesis. Treatment of rats with Pb acetate (PbAc, 50 mg/L in drinking water) significantly reduced sperm count, motility, viability and increased sperm abnormalities along with degenerative changes in seminiferous tubules and Leydig cells. Additionally, administration of PbAc resulted in a significant reduction in serum testosterone, serum and testicular E2 as well as increased level of testicular testosterone. Pb also induced testicular oxidative stress as evidenced by a significant decrease in the activities of superoxide dismutase, glutathione peroxidase and catalase antioxidant enzymes, and increased malondialdehyde level in the testis. At the molecular level, Pb treatment downregulated the mRNA expression of P450 arom (Cyp19) and ERα. In conclusion, Pb induces testicular oxidative damage and disrupts spermatogenesis, at least in part, via downregulation of Cyp19 and ERα expression, which further decrease E2 level. These data, therefore, provide insight into the mechanism of lead-induced testicular toxicity.

[Reversible cerebral vasoconstriction syndrome: A rare pediatric cause of thunderclap headaches]. / Syndrome de vasoconstriction cérébrale réversible : une cause de céphalée en coup de tonnerre peu connue chez l'enfant.

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by thunderclap headaches with diffuse segmental constriction of cerebral arteries that resolves spontaneously within 3 months. We report on a case of a 13-year-old boy presenting with acute severe headaches, triggered by physical exertion. His past medical history was uneventful. Moderate headache persisted between exacerbations for 4 weeks. He secondarily presented with signs of intracranial hypertension. Brain magnetic resonance angiography (MRA) revealed multifocal narrowing of the cerebral arteries. A glucocorticoid treatment was started based on the hypothesis of primary angiitis of the CNS. The symptoms rapidly improved, and repeat angiography at 3 months showed no vasoconstriction. Although pediatric cases are rare, RCVS should be considered in a child complaining of severe headache, especially after the use of vasoactive drugs or after Valsalva manoeuvres. RCVS is attributed to a transient, reversible dysregulation of cerebral vascular tone, which leads to multifocal arterial constriction and dilation. Physical examination, laboratory values, and initial cranial computed tomography are unremarkable, except when RCVS is associated with complications. Thunderclap headaches tend to resolve and then recur over a 1- to 4-week period, often with a milder baseline headache persisting between acute exacerbations. Angiography shows segmental narrowing and dilatation of one or more arteries, like a string of beads. Despite the absence of a proven treatment, important steps should be taken during the acute phase: removal of precipitants such as vasoactive substances, giving the patient rest, lowering blood pressure, and controlling seizures. Drugs targeted at vasospasms, such as calcium channel inhibitors, can be considered when cerebral vasoconstriction has been assessed. In most patients, the RCVS symptoms resolve spontaneously within days or weeks. Ischemic and hemorrhagic stroke are the major complications of the syndrome. A diagnosis of RCVS can only be confirmed when the reversibility of the vasoconstriction is assessed.

Transcranial color-coded sonography to predict recurrent transient ischaemic attack/stroke.

BACKGROUND AND PURPOSE: Patients with transient ischaemic attack (TIA) with a high risk of imminent stroke can be identified with the ABCD(2) score and findings on MRI and CT angiography. The predictive value of transcranial color-coded sonography (TCCS) has not been evaluated in this setting. METHODS: A retrospective analysis was conducted of patients consecutively treated for TIA or minor stroke in a TIA clinic within 24 h of symptom onset. Agreement between TCCS and MRI three-dimensional time-of-flight images for the diagnosis of proximal (internal carotid artery, vertebral artery, basilar artery, circle of Willis and main stem of the middle cerebral artery) >50% stenosis or occlusion of the intracranial symptomatic artery was evaluated. The sensitivity, specificity, predictive values and likelihood ratio of TCCS for predicting recurrent TIA/stroke at 7 days were calculated. RESULTS: Of 159 patients with a TIA or minor stroke within the last 24 h, 142 had a readable acoustic temporal bone window (89.3%). TCCS and MRI were performed within 4 h of each other in 116 patients. MRI showed a symptomatic proximal intracranial steno-occlusive lesion in six patients. Agreement between MRI and TCCS was perfect (κ coefficient = 1). Recurrent TIA/stroke occurred in 10 patients (eight TIA and two minor strokes). All recurrences occurred within 24 h of symptom onset. A symptomatic proximal intracranial steno-occlusive lesion was found on TCCS in 4/10 patients with recurrence and 3/132 patients without recurrence [sensitivity 40%; specificity 97.7%; likelihood ratio 18.1; odds ratio (95% CI) adjusted for ABCD(2) score 31.5 (4.5-218.6)]. CONCLUSION: Our study shows that TCCS can be used to guide triage of patients with TIA.

Intracranial artery stenosis or occlusion predicts ischemic recurrence after transient ischemic attack.

BACKGROUND AND PURPOSE: Patterns of DWI findings that predict recurrent ischemic events after TIA are well-established, but similar assessments of intracranial MRA findings are not available. We sought to determine the imaging characteristics of MRA that are predictive of early recurrent stroke/TIA in patients with TIA. MATERIALS AND METHODS: We performed a retrospective analysis of 129 consecutive patients with a clinical diagnosis of TIA in whom MR imaging was done within 24 hours of symptom onset. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of >50% stenosis or occlusion of symptomatic intracranial arteries for recurrent stroke/TIA at 7 days after TIA. We used logistic regression analysis to adjust for the clinical ABCD(2) score. We performed this analysis for symptomatic steno-occlusive lesions at any site and symptomatic steno-occlusive lesions on proximal large intracranial arteries (internal carotid artery, vertebral artery, basilar artery, and circle of Willis). RESULTS: Forty-two (32.5%) patients had acute ischemic lesions on DWI; 16 (12.4%) had significant MRA lesions, of which 11 (8.5%) were on proximal vessels. Nine patients had early recurrence (TIA, 7; minor stroke, 2). Only patients with proximal MRA lesions were at higher risk of early recurrence independent of the ABCD(2) score (adjusted odds ratio, 5.5; 95% confidence interval, 1.1-27.8; P = .04). CONCLUSIONS: Proximal lesions of cerebral arteries seen on MRA were predictive of recurrent stroke/TIA at 7 days. These findings suggest that MRA could be used to improve the selection of patients with TIA at high risk of early recurrent stroke/TIA.

Etiologic investigation of ischemic stroke in young adults.

OBJECTIVES: We attempted to classify causes of ischemic stroke in young adults using a progressive diagnostic algorithm and the ASCO (atherosclerosis, small-vessel disease, cardiac source, other cause) classification system. METHODS: Patients aged 16-54 years consecutively treated for acute ischemic stroke in a tertiary stroke unit were included in this retrospective analysis. Causes of stroke were classified using the ASCO system, which assigns a graded level of likelihood to each potential cause in individual patients. The initial etiologic workup included brain imaging, magnetic resonance or CT angiography of cerebral and cervical vessels, EKG, and routine blood studies. Patients without a definite cause of ischemic stroke after initial evaluation underwent transesophageal echocardiography. RESULTS: We included 318 patients (195 men and 123 women); 131 patients were aged 16-44 years, and 187 were aged 45-54 years. A definite cause of stroke (ASCO grade 1) could be identified in 145 patients (45.5%). An uncertain cause of stroke (ASCO grade 2) was found in 59 (18.5%) further patients. Most (130 of 145) definite causes were identified by initial evaluation. The 2 major definite or uncertain causes of stroke were patent foramen ovale associated with atrial septal aneurysm (PFO-ASA) (20 of 131 [15.3%]) and dissection of the cervical or cerebral artery (19 of 131 [14.5%]) in patients aged 16-44 years and large-vessel atherosclerosis (37 of 187 [19.8%]) and PFO-ASA (23 of 187 [12.3%]) in patients aged 45-54 years. CONCLUSIONS: Our findings suggest that PFO-ASA may be a major cause of ischemic stroke in young adults.

Autonomic neuropathy is associated with impairment of dynamic cerebral autoregulation in type 1 diabetes.

HYPOTHESIS: The mechanisms underlying impairment of dynamic cerebral autoregulation in diabetes are not well known. Cardiovascular autonomic neuropathy (CAN) could contribute to dynamic cerebral autoregulation impairment. In this study, we assessed the association between CAN and impairment of dynamic cerebral autoregulation in patients with type 1 diabetes. METHODS: We evaluated dynamic cerebral autoregulation (DCA) in patients with type 1 diabetes and no history of cerebrovascular disease. DCA was assessed with transcranial Doppler using the correlation coefficient index Mx method. Mx was calculated from slow changes in mean cerebral blood flow velocity and mean arterial blood pressure. Increase in Mx indicates weaker DCA, with a threshold for impaired DCA above 0.3. Moderate CAN was defined as reduced heart rate variability (HRV) on the following tests: deep controlled breathing, Valsalva maneuver or initiation of active standing. Severe CAN was defined as reduced HRV associated with orthostatic hypotension. RESULTS: 60 patients were included (M/F: 33/27; mean age ± SD: 46 years ± 11.5). 23 patients had moderate CAN and 15 patients severe CAN. DCA was impaired in 37 patients. CAN was associated with impaired DCA (p = 0.005). Impairment of DCA was more pronounced in patients with severe CAN (p = 0.019). Glycosylated haemoglobin (HbA1c) was associated with impaired DCA in univariate analysis (p = 0.05). In multivariate analysis, only CAN was associated with impaired DCA (p = 0.007) whereas HbA1c was not (p = 0.161). CONCLUSIONS: CAN was associated with impaired DCA in type 1 diabetes. The magnitude of DCA impairment increased with the severity of CAN.

The major determinant of exendin-4/glucagon-like peptide 1 differential affinity at the rat glucagon-like peptide 1 receptor N-terminal domain is a hydrogen bond from SER-32 of exendin-4.

BACKGROUND AND PURPOSE: Exendin-4 (exenatide, Ex4) is a high-affinity peptide agonist at the glucagon-like peptide-1 receptor (GLP-1R), which has been approved as a treatment for type 2 diabetes. Part of the drug/hormone binding site was described in the crystal structures of both GLP-1 and Ex4 bound to the isolated N-terminal domain (NTD) of GLP-1R. However, these structures do not account for the large difference in affinity between GLP-1 and Ex4 at this isolated domain, or for the published role of the C-terminal extension of Ex4. Our aim was to clarify the pharmacology of GLP-1R in the context of these new structural data. EXPERIMENTAL APPROACH: The affinities of GLP-1, Ex4 and various analogues were measured at human and rat GLP-1R (hGLP-1R and rGLP-1R, respectively) and various receptor variants. Molecular dynamics coupled with in silico mutagenesis were used to model and interpret the data. KEY RESULTS: The membrane-tethered NTD of hGLP-1R displayed similar affinity for GLP-1 and Ex4 in sharp contrast to previous studies using the soluble isolated domain. The selectivity at rGLP-1R for Ex4(9-39) over Ex4(9-30) was due to Ser-32 in the ligand. While this selectivity was not observed at hGLP-1R, it was regained when Glu-68 of hGLP-1R was mutated to Asp. CONCLUSIONS AND IMPLICATIONS: GLP-1 and Ex4 bind to the NTD of hGLP-1R with similar affinity. A hydrogen bond between Ser32 of Ex4 and Asp-68 of rGLP-1R, which is not formed with Glu-68 of hGLP-1R, is responsible for the improved affinity of Ex4 at the rat receptor.

Cerebral autoregulation in patients with obstructive sleep apnea syndrome during wakefulness.

BACKGROUND AND PURPOSE: Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for stroke. Impairment of cerebral autoregulation may play a potential role in the pre-disposition to stroke of OSAS patients. In this study, we aimed to assess dynamic cerebral autoregulation (DCA) during wakefulness in OSAS patients and a group of matched controls. METHODS: Patients and controls were examined in the morning after an overnight complete polysomnography. Mean cerebral blood flow velocity (CBFV) in the middle cerebral artery and mean arterial blood pressure (ABP) were continuously recorded using transcranial Doppler and Finapres. DCA was assessed using the Mx autoregulatory index. Mx is a moving correlation coefficient between mean CBFV and mean ABP. More positive value of Mx indicates worse autoregulation. RESULTS: Eleven OSAS patients (mean age +/- SD; 52.6 +/- 7.9) and 9 controls (mean age +/- SD; 49.1 +/- 5.3) were enrolled. The mean apnea-hypopnea index (AHI) in the OSAS group was of 22.7 +/- 11.6. No significant difference was found between the two groups as for age, body mass index, mean ABP and endtidal CO(2) pressure. Cerebral autoregulation was impaired in OSAS patients compared with controls (Mx index: 0.414 +/- 0.138 vs. 0.233 +/- 0.100; P = 0.009). The severity of autoregulation impairment correlated to the severity of the sleep respiratory disturbance measured by the AHI (P = 0.003). CONCLUSION: Cerebral autoregulation is impaired in patients with OSAS during wakefulness. Impairment of cerebral autoregulation is correlated with the severity of OSAS.

Peptide binding at the GLP-1 receptor.

The receptor for GLP-1 [glucagon-like peptide-1-(7-36)-amide] is a member of the 'Family B' of GPCRs (G-protein-coupled receptors) comprising an extracellular N-terminal domain containing six conserved cysteine residues (the N-domain) and a core domain (or J-domain) comprising the seven transmembrane helices and interconnecting loop regions. According to the two-domain model for peptide binding, the N-domain is primarily responsible for providing most of the peptide binding energy, whereas the core domain is responsible for binding the N-terminal region of the peptide agonists and transmitting the signal to the intracellular G-protein. Two interesting differences between the binding properties of two GLP-1 receptor agonists, GLP-1 and EX-4 (exendin-4), can be observed. First, while GLP-1 requires its full length to maintain high affinity, the eight N-terminal residues of EX-4 can be removed with little reduction in affinity. Secondly, EX-4 (but not GLP-1) can bind to the fully isolated N-domain of the receptor with an affinity matching that of the full-length receptor. In order to better understand these differences, we have studied the interaction between combinations of full-length or truncated ligands with full-length or truncated receptors.