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.     

Effect of melatonin in the prevention of post-operative adhesion formation in a rat uterine horn adhesion model

BACKGROUND: Our main aim was to investigate the effects of melatonin (ME), possibly the most powerful free-radical scavenger, on the prevention of i.p. adhesion formation in rat uterine horn. Our secondary aim was to determine whether different methods of administration of ME were beneficial. METHODS: Animals were randomly assigned into seven groups, each consisting of 13 rats. Measured serosal injury was created using a standard technique. While control and two sham groups were not given ME, two of the remaining four groups were given a single dose of 10 mg/kg (2 mg) of ME i.p. immediately after injury and 30 min prior to injury respectively. In the two other groups, ME treatment was continued daily for 5 days. All animals were killed 2 weeks after surgery and adhesions were determined and scored by a examiner blinded to the test. RESULTS: The extent, severity and total scores of adhesion were found to be significantly reduced in all of the ME treatment groups when compared with control and sham groups. There were no statistically significant differences between the treatment groups. CONCLUSIONS: This study showed that even single dose ME therapy was effective in the prevention of post- operative i.p. adhesion formation.     

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.     

Grape seed extract treatment reduces hepatic ischemia-reperfusion injury in rats

This study was designed to determine the possible protective effect of grape seed extract (GSE), a widely used antioxidant dietary supplement, on hepatic ischemia/reperfusion (I/R) injury. Wistar albino rats were subjected to 45 min of hepatic ischemia, followed by a 60 min reperfusion period. GSE was administered in a dose of 50 mg/kg/day orally for 15 days before I/R injury and repeated before the reperfusion period. Liver samples were taken for histological examination or determination of hepatic malondialdehyde (MDA), glutathione (GSH) and myeloperoxidase (MPO) activity. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were determined to assess liver functions. Lactate dehydrogenase (LDH) and cytokines (TNF-alpha and IL-1 beta) were also assayed in serum samples for the evaluation of generalized tissue damage. Ischemia/reperfusion caused a significant decrease in hepatic GSH, and significant increases in MDA level, and MPO activity. Serum AST and ALT levels, as well as LDH activity and plasma TNF-alpha and IL-1beta levels were also elevated in the I/R group. Treatment with GSE reversed all these biochemical parameters as well as histological alterations induced by I/R. In conclusion, GSE reduced I/R-induced organ injury through its ability to balance the oxidant-antioxidant status, to inhibit neutrophil infiltration and to regulate the release of inflammatory mediators.     

Why do infants pull their ears?

ObjectiveIn this study, we aimed to evaluate the diagnoses of the infants who were admitted to our outpatient clinic with the complaint of pulling on the ear and to identify the related factors which may contribute to the diagnosis.MethodsThis prospective study included a total of 102 infants who were admitted to our hospital with the complaint of tugging and pulling on, touching, and rubbing the ears on the shoulder or pillow and shaking the head between July 2016 and July 2017. The complaints were evaluated throughout the day, and the application seasons, the person referred the patient to the ear, nose, and throat (ENT) specialist, the child development specialist and child psychiatrist, allergy and atopy histories, and the relationship between the results and diagnoses were evaluated.Results46.1% of the patients had normal examination findings, while the second most common finding was cerumen in 37.2%, and the third one was otitis media with effusion (OME) in 16.7%. In infants who were directly referred by the family, normal and serological diagnosis were found to be statistically significantly higher than that of OME diagnosis, whereas in the infants referred by the family physicians and pediatrist, the OME was found to be statistically significantly higher than normal and cerumen levels. The presence of additional complaints in the OME group was found to be higher than normal and cerumen group. In those with complaints during the day, the most common finding was OME, while it was cerumen in those with complaints a few times in a day and normal examination finding in those tugging on their ears only, when they were falling asleep, indicating statistical significance. Of 47 infants with normal physical examination findings, 37 were assessed by the child psychiatrist, and depression was found in six of one of the parents during the family interviews.ConclusionIn this study, the majority of the infants referred to the ENT outpatient clinic had normal examination findings, while the rate of OME diagnosis was high. Considering the negative consequences of EOM in infants, the diagnosis of the EOM becomes extremely important. If there are no otologic pathologies in the majority of infants who were admitted with ear pulling and tugging, the possibility of different factors in etiology gives rise to thought. Therefore, further studies are required to prove this condition.