Molecular association in aqueous solutions of high molecular weight poly(N-vinyl-2-pyrrolidone)

A viscosimetric method was used to investigate the molecular association in aqueous solutions of poly(N-vinyl-2-pyrrolidone), (PVP), of molecular weight 700 000. Limiting viscosity numbers [η] and Huggins constants k_H of the polymer solutions were observed to decrease upon addition of denaturing agents such as thiourea and guanidinium sulfate. Guanidinium sulfate was found to be even more effective in its denaturing action as compared to urea and thiourea. The decrease in [η] and k_H values increased with increasing concentrations of the denaturing agents. This behaviour was explained on the basis of the rupture of bridges formed by water molecules among different PVP chains, hydrogen bonding being responsible for these intermolecular associations. While no change in the [η] values was observed for PVP in 2 M thiourea solutions upon increasing the temperature from 25°C to 35 and 45°C, for the same increase in temperature the [η] values of aqueous PVP solutions showed substantial decreases. This is also attributed to the breaking of hydrogen bonds existing between PVP molecules.     

Early impact of hormone replacement therapy on vascular hemodynamics detected via ocular colour Doppler analysis

Objective: To determine the effects of hormone replacement therapy (HRT) on ocular blood flow.

Study design: In a prospective controlled study, 40 healthy women who presented to the menopause clinic between December 2000 and December 2001 were randomly assigned into the study. The HRT-receiving group was administered estradiol 17-valerate 2 mg the first 11 days, and estradiol 17-valerate 2 mg plus ciproterone acetate 1 mg the next 10 days of the monthly cycle for 6 months. The control group did not receive any HRT for 6 months. The ocular colour Doppler analysis were performed at baseline and after 3 and 6 months. The ocular Doppler analysis was performed in the first half of the cycle in the HRT-receiving group.

Results: Central retinal artery and ophthalmic artery basal Doppler index (peak systolic velocity, end-diastolic velocity, resistive index and pulsatility index) values of the two groups at the beginning of the study did not show any statistically significant difference. Both the right and the left central retinal artery pulsatility index (PI) values of the study group, who received HRT at the end of the third and sixth months, showed a statistically significant decline (paired-samples test, P < 0.05), while the decrease in the resistive indexes was not significant.

Conclusion: These results suggest that 6 months of combined hormone replacement therapy with estradiol 17-valerate 2 mg plus ciproterone acetate 1 mg improves ocular vascular Doppler indices which may be a reflection of cerebral vascular status.     

The “vaccine” hubbub: Viral load comparisons of SARS-CoV-2 Delta and Omicron variants against different vaccine–booster vaccine combinations

There is a significant body of evidence showing that efficient vaccination schemes against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is helping control the coronavirus disease 2019 (COVID-19) pandemic. However, this goal cannot be achieved without real world data highlighting the impact of vaccines against viral spread. In this study, we have aimed at differentially investigating the impact of COVID-19 vaccines (CoronaVac, Pfizer/BioNTech, Astra/Zeneca Oxford, Janssen) used in North Cyprus in limiting the viral load of Delta and Omicron variants of SARS-COV-2. We have utilized real-time quantitative polymerase chain reaction cycle threshold values (Ct values) as a proxy of viral load of the two SARS-CoV-2 variants. Our results indicate that the administration of at least two doses of the messenger RNA-based Pfizer/BioNTech vaccine leads to the lowest viral load (highest Ct values) obtained for both Omicron and Delta variants. Interestingly, regardless of the vaccine type used, our study revealed that Delta variant produced significantly higher viral loads (lower Ct values) compared with the Omicron variant, where the latter was more commonly associated with younger patients. Viral spread is a crucial factor that can help determine the future of the pandemic. Thus, prioritizing vaccines that will play a role in not only preventing severe disease but also in limiting viral load and spread may contribute to infection control strategies.     

Working with the bereaved: U.S. Army experiences with nontraditional families

This paper uses a postmodern family perspective to examine the interaction between Army Casualty Assistance Officers (CAOs) and the families of deceased soldiers. The data we examine are open-ended survey responses of CAOs (N = 188) who assisted bereaved families of soldiers killed in three unrelated air disasters. Five themes emerged from our analysis of the qualitative responses: postmodern family structures, contested definitions of “significant other,” language, diversity, and emotion. These themes appear to be related to the difficult demands associated with bereavement work. We argue that the experiences of the CAO are comparable to the experiences of others who may work with the bereaved (e.g., police officers, medical workers, and disaster workers) when working in similar familial contexts.     

Cephalic vein thrombosis

An 83‐year‐old male patient presented to the outpatient clinic with complaint of swelling at right antecubital area. Ultrasonographic examination of the right upper extremity revealed a mass lesion within the right cephalic vein, which was consistent with thrombus. A computed tomography (CT) venography showed contrast enhancement in cephalic vein at distal arm and an aneurysmatic thrombus area displaying regular borders with a size of 28*30 mm; there was no contrast enhancement at more proximal levels at the cephalic vein.     

Gender Dysphoria and Perceived Social Support: A Matched Case-Control Study

BackgroundIn people diagnosed with Gender Dysphoria (GD), low perceived social support from their families and society has been suggested to be associated with poor quality of life and mental well-being.AimTo compare the perceived social support in individuals with GD with that in individuals without GD matched for age and gender.MethodsThe study group (n = 50) consisted of individuals diagnosed with GD via psychiatric evaluation. A control group (n = 50) was created by matching volunteers without GD by age and gender. Sociodemographic data form, Structured Clinical Interview Form for DSM-IV TR Axis I Disorders (SCID-I), and Multidimensional Scale of Perceived Social Support (MSPSS) were used to gather data from participants.Outcomescomparing the perceived social support, the total and subscale MSPSS scores of groups were calculated.ResultsThe presence of at least 1 psychiatric disorder was significantly higher in the GD group than in the control group, either lifetime or during evaluation (P < .001 and P = .025, respectively). The total MSPSS and family support subscale scores were found to be significantly lower in the GD group than in the control group (P = .001 and P ≤ .001, respectively). When the groups formed on the basis of gender identity (32 trans men vs 32 cis men and 18 trans women vs 18 cis women) were compared, only the family support subscale score was found to be lower in trans men than cis men (P = .005). In addition, comparisons within the groups formed based on sex assigned-at-birth revealed lower total, friend, and family support in those assigned female-at-birth and lower total and family support in those assigned male-at-birth in the GD group. A multiple linear regression analysis revealed that the presence of GD was significantly associated with total and family support MSPSS subscale scores.Clinical ImplicationsThe findings show that perceived social support in people diagnosed with GD is lower, even when the presence of psychiatric disorders is included in the analysis.Strengths and LimitationsThe matched case-control design was the major study strength, whereas the sample size was the major limitation.ConclusionClinical care of people diagnosed with GD should include the evaluation of diverse sources of social support, efforts to strengthen family and friend support, maintenance of interpersonal relationships, and support of mental well-being.Kaptan S, Cesur E, Ba?ar K, et al. Gender Dysphoria and Perceived Social Support: A Matched Case-Control Study. J Sex Med 2021;18:812–820.     

Coiled-coil irregularities of the M1 protein structure promote M1–fibrinogen interaction and influence group A Streptococcus host cell interactions and virulence

Group A Streptococcus (GAS) is a human pathogen causing a wide range of mild to severe and life-threatening diseases. The GAS M1 protein is a major virulence factor promoting GAS invasiveness and resistance to host innate immune clearance. M1 displays an irregular coiled-coil structure, including the B-repeats that bind fibrinogen. Previously, we found that B-repeat stabilisation generates an idealised version of M1 (M1*) characterised by decreased fibrinogen binding in vitro. To extend these findings based on a soluble truncated version of M1, we now studied the importance of the B-repeat coiled-coil irregularities in full length M1 and M1* expressed in live GAS and tested whether the modulation of M1–fibrinogen interactions would open up novel therapeutic approaches. We found that altering either the M1 structure on the GAS cell surface or removing its target host protein fibrinogen blunted GAS virulence. GAS expressing M1* showed an impaired ability to adhere to and to invade human endothelial cells, was more readily killed by whole blood or neutrophils and most importantly was less virulent in a murine necrotising fasciitis model. M1-mediated virulence of wild-type GAS was strictly dependent on the presence and concentration of fibrinogen complementing our finding that M1–fibrinogen interactions are crucial for GAS virulence. Consistently blocking M1–fibrinogen interactions by fragment D reduced GAS virulence in vitro and in vivo. This supports our conclusion that M1–fibrinogen interactions are crucial for GAS virulence and that interference may open up novel complementary treatment options for GAS infections caused by the leading invasive GAS strain M1.