Photobodies: Light-Activatable Single-Domain Antibody Fragments.

Photocaged antibody fragments, termed photobodies, have been developed that are impaired in their antigen-binding capacity and can be activated by irradiation with UV light (365 nm). This rational design concept builds on the selective photocaging of a single tyrosine in a nanobody (a single-domain antibody fragment). Tyrosine is a frequently occurring residue in central positions of the paratope region. o-Nitrobenzyl-protected tyrosine variants were incorporated into four nanobodies, including examples directed against EGFR and HER2, and photodeprotection restores the native sequence. An anti-GFP photobody exhibited an at least 10 000-fold impaired binding affinity before photodeprotection compared with the parent nanobody. A bispecific nanobody-photobody fusion protein was generated to trigger protein heterodimerization by light. Photoactivatable antibodies are expected to become versatile protein reagents and to enable novel approaches in diagnostic and therapeutic applications.

Altered Coordination of Individual Catalytic Steps in Different and Evolved Inteins Reveals Kinetic Plasticity of the Protein Splicing Pathway.

Protein splicing performed by inteins provides powerful opportunities to manipulate protein structure and function, however, detailed mechanistic knowledge of the multistep pathway to help engineering optimized inteins remains scarce. A typical intein has to coordinate three steps to maximize the product yield of ligated exteins. We have revealed a new type of coordination in the Ssp DnaB intein, in which the initial N- S acyl shift appears rate-limiting and acts as an up-regulation switch to dramatically accelerate the last step of succinimide formation, which is thus coupled to the first step. The structure-activity relationship at the N-terminal scissile bond was studied with atomic precision using a semisynthetic split intein. We show that the removal of the extein acyl group from the α-amino moiety of the intein's first residue is strictly required and sufficient for the up-regulation switch. Even an acetyl group as the smallest possible extein moiety completely blocked the switch. Furthermore, we investigated the M86 intein, a mutant with faster splicing kinetics previously obtained by laboratory evolution of the Ssp DnaB intein, and the individual impact of its eight mutations. The succinimide formation was decoupled from the first step in the M86 intein, but the acquired H143R mutation acts as a brake to prevent premature C-terminal cleavage and thereby maximizes splicing yields. Together, these results revealed a high degree of plasticity in the kinetic coordination of the splicing pathway. Furthermore, our study led to the rational design of improved M86 mutants with the highest yielding trans-splicing and fastest trans-cleavage activities.

Overactive bladder syndrome and bladder wall thickness in patients with obstructive sleep apnea syndrome.

OBJECTIVE: The main objective of the present study was to evaluate the presence of overactive bladder (OAB) syndrome, nocturia, urgency, and urge incontinence in patients with obstructive sleep apnea syndrome (OSAS), and measure bladder wall thickness (BWT) in these patients. MATERIALS AND METHODS: The patient group was composed of 38 patients with OSAS. The control group was composed of 15 healthy individuals. All patients were evaluated using the Epworth Sleepiness Scale (ESS) and Overactive Bladder Symptom Score (OABSS). The bladder wall thickness was measured by transabdominal ultrasound (US). The presence of nocturia, urinary urgency, and urge incontinence were also evaluated. RESULTS: The mean OABSS was significantly higher in the patient group compared with the control group (p=0.048). The minimum oxygen saturation (Min.SO2) of patients with urgency was found to be significantly lower (p=0.014). The time spent below 90% of oxygen saturation (SO2) was significantly longer in patients with urinary urgency (p=0.009). There was no difference in BWT measurements between the patient group and the control group. There was a significant relationship between BWT values and OABSS in patients with OSAS (p=0.002). CONCLUSION: The results of the present study suggest that OSAS is associated with OAB syndrome. As a key symptom of OAB, urgency correlates with hypoxia in cases with OSAS. Although the present study did not observe any difference in BWT measurements between the patients and the control group, there was a correlation between BWT measurements and OABSS in patients with OSAS.

Bone mineral density and changes in bone metabolism in patients with obstructive sleep apnea syndrome.

The aim of this study was to evaluate the differences between patients with obstructive sleep apnea syndrome (OSAS) and phenotypically similar subjects without OSAS in terms of bone mineral density (BMD) and bone turnover markers. The study was conducted on 30 males diagnosed with OSAS and 20 healthy males. All subjects underwent polysomnographic testing. Calcium, phosphorus parathyroid hormone, thyroid stimulating hormone, bone-specific alkaline phosphatase, 25-hydroxyvitamin D3, osteocalcin, and beta-CrossLaps (ß-CTx) were measured. BMD in the lumbar spine (L1-L4) and femoral neck was measured by dual energy X-ray absorptiometry. There was no statistically significant difference between the two groups in terms of demographic data with the exception of bone mass index and waist circumference. (p < 0.05). Analyses showed significantly lower BMD measurements in the femoral neck and T-scores in the femoral neck in patients diagnosed with OSAS. Serum ß-CTx levels were found to be statistically significantly higher in the OSAS group (p = 0.017). In multivariate assessments performed for apnea/hypopnea index values, mean saturation O2 levels were found to be significantly associated with osteocalcin levels and neck BMD. OSAS patients might represent a risk group with respect to loss of BMD and bone resorption. It is important to evaluate bone loss in these patients. Further studies should be carried out on larger study populations to evaluate the effects of chronic hypoxia on BMD in detail.

Design and Preparation of Photobodies: Light-Activated Single-Domain Antibody Fragments.

Nanobodies are single-domain antibody fragments that have found widespread use in basic research, therapy, and diagnostics. Like other antibody formats, nanobodies can be developed with high affinity and specificity for desired antigens. A photobody is a light-activatable nanobody, obtained by incorporating a photo-labile caging group into the paratope region. The caging group prevents antigen binding until removed with light (365 nm), thereby rendering the binding controllable with high temporal and spatial resolution. Thus far photocaged tyrosine residues have been used for this purpose, as tyrosine is a frequent residue at critical positions of nanobody paratopes. Nanobodies without a tyrosine residue at the antigen-binding interface may require a different strategy. In this chapter, we describe methods to design and prepare photobodies by recombinant expression in Escherichia coli in combination with genetic code expansion technology to incorporate ortho-nitrobenzyl-tyrosine residues. We use the conversion of the anti-green fluorescent protein enhancer nanobody into a photobody as an example. These protocols should be applicable to many other nanobodies.

The clinical and urodynamic results of a 3-month percutaneous posterior tibial nerve stimulation treatment in patients with multiple sclerosis-related neurogenic bladder dysfunction.

AIM: The aim of this study was to investigate the effect of PTNS after 12 weeks, on the urodynamic findings in the Multiple Sclerosis (MS) patients with neurogenic detrusor overactivity (NDO). METHODS: A total of 19 MS patients with NDO were enrolled in the study. Urodynamic studies before and after 12 weeks PTNS were performed. PTNS was applied unilaterally from the medial malleolus and posterior to the edge of the tibia by using charge-compensated 200 micros pulses with a pulse rate of 20 Hz, weekly, during 3 months. The effects of PTNS on urodynamic variables were compared of baseline and after PTNS data in MS patients. RESULTS: Mean volume at the first involuntary detrusor contraction (1st IDCV) on standard cystometry was 124.2+/-37.6 ml, while it was 217.5+/-66.4 mL after PTNS. Mean maximum cystometric capacity (MCC) on standard cystometry was 199.7+/-29.3 mL, while it was 266.8+/-36.9 mL after stimulation. The improvements in the 1st IDCV and MCC were statistically significant after stimulation. Mean P(detmax) at first involuntary detrusor contraction, maximal detrusor pressure at maximum cystometric capacity, detrusor pressure at maximal flow (P(detQmax)) and maximal flow rate (Q(max)) were statistically significant after PTNS for 12 weeks. CONCLUSIONS: These results have demonstrated that PTNS is effective to suppress NDO in MS patients after PTNS. Although long-term efficacy of PTNS is known, the findings showed prominent improvements on the clinical and urodynamic outcome, we think that the use of PTNS for DO in MS patients will be promising in clinical practice in the future.

The role of upper airway morphology in apnea versus hypopnea predominant obstructive sleep apnea patients: an exploratory study.

OBJECTIVE: The objective of this study was to investigate the association between upper airway morphology and apnea vs hypopnea predominance in patients with obstructive sleep apnea (OSA) syndrome. METHODS: A retrospective study on consecutively CT scans obtained from 54 OSA patients and 53 non-snoring controls. CT scans were measured to evaluate upper airway and surrounding structures' morphologic characteristics. OSA patients (matched for age, gender and body mass index) compared as two groups; apneic group: apnea ratio >50% and hypopneic group: hypopnea ratio >50%. Morphologic characteristics were analyzed using Kruskal-Wallis test and Pearson's correlation test. RESULTS: Apneic group (17 patients) showed 76.56% apnea rate and hypopneic group (37 patients) showed 78.46% hypopnea rate. Minimal lateral and anteroposterior dimensions of velopharynx in the apneic group (0.86 ± 0.73 and 0.21 ± 0.13 cm, respectively) was statistically lesser from that of the hypopneic group (1.2 ± 0.42 and 0.54 ± 0.22 cm, respectively). Minimum cross-sectional area of the velopharynx was also lesser in apneic group (0.21 ± 0.16 cm2) than that in hypopneic group (0.65 ± 0.38 cm2). Almost all upper airway parameters in both apneic and hypopneic groups were tended to be smaller than in controls. CONCLUSION: Decrease in airway volume does not signify the type of respiratory event, but significant narrowing of velopharynx in both dimensions; thus having the narrowest value below a certain level causes more apnea. Advances in knowledge: We did not find a similar study when we did a literature search, showing the relationship of apnea vs hypopnea predominance and upper airway parameters in CT in patients with OSA.

Evaluation of pain sensitivity by tender point counts and myalgic score in patients with and without obstructive sleep apnea syndrome.

AIM: The purpose of this study was to assess the difference between patients with and without obstructive sleep apnea syndrome (OSAS) with respect to pain sensitivity. METHOD: The study was conducted on 31 womens diagnosed with OSAS and 31 healthy women. All patients underwent polysomnographic testing. A pressure algometer (dolorimeter) was used to measure the pressure pain threshold. Fibromyalgia was diagnosed based on the 1990 American College of Rheumatology diagnosis criteria. RESULTS: The myalgic score was 73.95 ± 18.09 in patients with OSAS, while this value was 84.18 ± 24.31 in the control group. The difference between the groups was statistically significant (P = 0.041).The number of tender points was 8.19 ± 3.35 in the patient group with OSAS, while this number was 6.35 ± 2.23 in the control group. The difference between the two groups was statistically significant (P = 0.014). No statistically significant differences were found between age, body mass index, Beck depression scores, control point score and the presence of fibromyalgia, between the two groups (P > 0.05). A statistically significant positive correlation was found between the myalgic scores and mean saturation O2 (%) values of the patients (r = 0.357; P = 0.049). CONCLUSION: The differences noted between OSAS patients and the control group with respect to myalgic score and the number of tender points suggest that there might be a relation between OSAS and pain sensitivity. There might be an association between low oxygen saturation and total myalgic score.

Sexual Dysfunction in Premenopausal Women With Obstructive Sleep Apnea.

PURPOSE: Sexual functions in the males with obstructive sleep apnea syndrome (OSAS) have been well investigated in the literature; however sexual functions in the premenopausal women with OSAS have been studied to a lesser extent. MATERIALS AND METHODS: The study included 22 premenopausal women diagnosed as OSAS by the polysomnographic (PSG) evaluation. The control group included 13 premenopausal women suspected of sleep-relatedrespiratory disorder, but whose PSG tests were determined to be normal. Both groups were administered Epworth Sleep Scale (ESS), Beck Depression Scale (BDS), and Female Sexual Function Index (FSFI) questionnaire forms. Relations between disease parameters, and the total FSFI score, and scores of the six FSFI parameter were analyzed. RESULTS: The total FSFI score in the cases with OSAS, was determined to be significantly lower than that of the control subjects (P = .031). Scores of the desire, arousal, and orgasm were determined to be significantly lower inthe patient group, compared to control group (P = .034; P = .048; P = .039). The total FSFI scores, and scores of the desire, arousal, lubrication, orgasm, satisfaction and pain subscales in the cases did not correlate significantly with the apnea-hypopnea index (AHI), Non-Rapid Eye Movement 1 (NREM1)%, NREM2%, NREM3%, REM%, the time spent with saturation O2< 90%, minimum oxygen saturation (%), ESS scores, and BDS scores (all P > .05). CONCLUSION: Women with OSAS experience sexual dysfunction when compared with normal population. Clinical evaluation has to include also the evaluation of sexual life in women.

Medially displaced common and internal carotid arteries presenting as a pulsatile mass: Clinicoradiologic analysis of 62 cases.

We conducted a prospective study to analyze the medially displaced courses of the common carotid artery (CCA) and the cervical segment of the internal carotid artery (ICA) in patients who were diagnosed with a pulsatile mass on nasopharyngolaryngoscopy and by clinicoradiologic findings. Our study group was made up of 62 patients-40 women and 22 men, aged 30 to 88 years (mean: 63.7)-who presented with a submucosal pseudomass or a bulging mass on the pharyngeal wall with obvious pulsation. For comparison purposes, we recruited a control group of 62 consecutively presenting patients who had been admitted to our Neurology Department with acute severe headache and who had undergone CT angiography based on a suspicion of an aneurysm or a vertebral or carotid artery dissection. A medially displaced carotid artery was identified in all patients in the study group. Two main course abnormalities were observed: (1) a pharyngeal superficial placement (PSP), consisting of a bulging or placement immediately adjacent to the naso-orohypopharyngeal lumen, and (2) a retropharyngeal midline placement (RMP), which entailed medialization of the carotid arteries to the midline. A PSP was observed in 11 patients, an RMP was found in 17 patients, and both were seen in 34 patients. The distance from the aberrant carotid artery to the pharyngeal wall and to the retropharyngeal midline of the retropharynx was measured at four levels: nasopharyngeal, retropalatal, retroglossal, and retroepiglottic in both groups. The mean distance was significantly shorter in the study group than in the control group at all four levels (p < 0.002). We conclude that the most likely diagnosis of a pulsatile mass detected on nasopharyngolaryngoscopy is an aberrant CCA or cervical ICA.

Factors affecting executive functions in obstructive sleep apnea syndrome and volumetric changes in the prefrontal cortex.

PURPOSE: Obstructive sleep apnea syndrome (OSAS) is associated with cognitive changes and executive functions are among the cognitive domains most affected. However, it is not completely understood which of the factor(s) among hypoxemia, repeated arousal, and sleepiness affect the executive functions. This study aims to evaluate the possible relationship between the executive functions and nocturnal parameters, Epworth Sleepiness Scale (ESS) scores, and prefrontal cortex (PFC) volumes. PATIENTS AND METHODS: A total of 28 patients aged between 18 and 60 years who were newly diagnosed with OSAS were included in this study. The Wisconsin Card Sorting Test (WCST) and Stroop test which were used in the evaluation of executive functions were applied to all patients. Cranial magnetic resonance imaging (MRI) and volumetric measurements of the PFC were performed. Polysomnography (PSG), WCST, Stroop test, and cranial MRI were also applied to the control group which consisted of age- and education status-matched 15 healthy subjects. The correlation of WCST and Stroop tests and PFC volume, PSG parameters, and ESS scale was examined. RESULTS: The WCST-6 test scores were statistically significantly higher in the patient group (p = 0.022; p < 0.05). Additionally, the Stroop test 5 (p = 0.043) and Stroop test-5 correction (p = 0.005) measurements were statistically significantly higher in the patient group (p < 0.05). A negative and statistically significant correlation was found between the WCST-4 and WCST-10 and ESS measurements in the patient group (r -0.452; p 0.016; p < 0.05; r -0.437; p 0.020; p < 0.05). However, there was no correlation between the PSG parameters and WCST and Stroop test scores. No statistically significant differences in the MRI volumetric measurements of the PFC were found between the patient and control groups. CONCLUSIONS: Impairment in the attentive and executive functions in OSAS is evident. The most influential factor is excessive daytime sleepiness, rather than hypoxemia and severity of the disease.

[Mean platelet volume play a role in disease severity in patients with obstructive sleep apnea syndrome?]. / Tikayici uyku apne sendromunda ortalama trombosit hacminin hastalik siddetinde rolü var midir?

OBJECTIVES: This study aims to show the effects of nasal continuous positive airway pressure (CPAP) treatment on platelet activation in patients with severe obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS: Forty-six patients (29 males, 17 females; mean age 48.2±7.6 years; range 40 to 56 years) with severe OSAS with apnea/hypopnea index (AHI) ≥30 were included in this study. Complete blood counts were analyzed and mean platelet volume (MPV) values were compared in patients before and after CPAP treatment at six months. RESULTS: The mean MPV values before CPAP were 8.9±1.3 (p<0.001), while the mean values were 7.7±1.1 (p<0.001) at six months after CPAP treatment in patients with severe OSAS. There was a statistically significant decrease in the MPV values after CPAP treatment. Patients' number of platelets which was measured six months after the CPAP treatment increased at a significant level compared to baseline (p<0.001). CONCLUSION: Continuous positive airway pressure treatment caused a significant decrease in the MPV values in patients with severe OSAS. As a negative acute phase reactant, MPV can be used as a marker to exert the cardioprotective effect of CPAP.

Overactive bladder syndrome and bladder wall thickness in patients with obstructive sleep apnea syndrome

ABSTRACT Objective The main objective of the present study was to evaluate the presence of overactive bladder (OAB) syndrome, nocturia, urgency, and urge incontinence in patients with obstructive sleep apnea syndrome (OSAS), and measure bladder wall thickness (BWT) in these patients. Materials and Methods The patient group was composed of 38 patients with OSAS. The control group was composed of 15 healthy individuals. All patients were evaluated using the Epworth Sleepiness Scale (ESS) and Overactive Bladder Symptom Score (OABSS). The bladder wall thickness was measured by transabdominal ultrasound (US). The presence of nocturia, urinary urgency, and urge incontinence were also evaluated. Results The mean OABSS was significantly higher in the patient group compared with the control group (p=0.048). The minimum oxygen saturation (Min.SO2) of patients with urgency was found to be significantly lower (p=0.014). The time spent below 90% of oxygen saturation (SO2) was significantly longer in patients with urinary urgency (p=0.009). There was no difference in BWT measurements between the patient group and the control group. There was a significant relationship between BWT values and OABSS in patients with OSAS (p=0.002). Conclusion The results of the present study suggest that OSAS is associated with OAB syndrome. As a key symptom of OAB, urgency correlates with hypoxia in cases with OSAS. Although the present study did not observe any difference in BWT measurements between the patients and the control group, there was a correlation between BWT measurements and OABSS in patients with OSAS.

Perception of epilepsy in Turkey in the light of two different cities.

The aim of this study was to investigate the perception of epilepsy in Turkey, from west to east, in Kutahya and Yuksekova, two cities of different sociocultural and ethnic status. This was a retrospective comparison study which evaluated the results of two prior studies investigating stigmatization of patients diagnosed with epilepsy and their first-degree relatives in two different cities of Turkey, Kutahya and Yuksekova. The Survey of Epileptic Patient Relatives on the Knowledge, Attitudes, and Behavior Regarding the Disorder was used and included questions on descriptive characteristics, familiarity with epilepsy, attitudes toward epilepsy, and understanding of epilepsy. Data collected by use of the SPSS 15.0 software were analyzed with chi2-test. In Yuksekova group, 88.5% of first-degree relatives of people with epilepsy felt primarily fear when they heard the diagnosis of epilepsy in their relatives; in Kutahya group, the respective rate was 19.1% (p < 0.05). The number of participants who objected their child marrying someone with epilepsy was significantly higher in Yuksekova group (p < 0.05); however, if married, the Yuksekova group significantly stated that they should have a baby, revealing the importance of children as an indicator of power and dignity in the eastern region of Turkey (p < 0.05). Although understanding of epilepsy was favorable, educating the community about epilepsy and personal contacts are the major strategies against epileptic stigmatization.