The Impact of Incubation Conditions on In Vitro Phosphatidylcholine Deposition on Contact Lens Materials.

SIGNIFICANCE: Previous in vitro measurements of contact lenses commonly investigate the impact of nonpolar tear film lipids (i.e., sterols). Polar lipids, however, are equally important stabilizing components of the tear film. This research explores and presents further knowledge about various aspects of polar lipid uptake that may impact contact lens performance. PURPOSE: This study evaluated the impact of incubation time, lipid concentration, and replenishment of an artificial tear solution (ATS) on the uptake of phosphatidylcholine (PC) onto conventional hydrogel (CH) and silicone hydrogel (SH) contact lens materials. METHODS: Four SHs and two CH lens materials (n = 4) were soaked in a complex ATS containing radioactive 14C-PC as a probe molecule. Phosphatidylcholine uptake was monitored at various incubation time points (1, 3, 7, 14, and 28 days), with different ATS lipid concentrations (0.5×, 1×, 2×) and with and without regular replenishment of the ATS. Phosphatidylcholine was extracted from the lenses, processed, and counted by a ß counter, and accumulated PC (µg/lens) was extrapolated from standard lipid calibration curves. RESULTS: All materials exhibited increasing PC deposition over time. Conventional hydrogel materials showed significantly lower PC uptake rates (P < .001) than any of the SH materials. Increasing lipid concentration in the ATS resulted in increased PC binding onto the contact lens materials (P < .001). Replenishing the ATS every other day, however, impacted the PC deposition differently, showing increased binding (P < .001) on CHs and reduced PC deposition for SH materials (P < .001). CONCLUSIONS: Length of incubation, lipid concentration in the ATS, and renewal of the incubation solution all influenced the amount of PC that sorbed onto various lens materials and therefore need to be considered when conducting future in vitro deposition studies.

Essential role of autophagy in restricting poliovirus infection revealed by identification of an ATG7 defect in a poliomyelitis patient.

Paralytic poliomyelitis is a rare disease manifestation following poliovirus (PV) infection. The disease determinants remain largely unknown. We used whole exome sequencing to uncover possible contributions of host genetics to the development of disease outcome in humans with poliomyelitis. We identified a patient with a variant in ATG7, an important regulatory gene in the macroautophagy/autophagy pathway. PV infection did not induce a prominent type I interferon response, but rather activated autophagy in neuronal-like cells, and this was essential for viral control. Importantly, virus-induced autophagy was impaired in patient fibroblasts and associated with increased viral burden and enhanced cell death following infection. Lack of ATG7 prevented control of infection in neuronal-like cells, and reconstitution of patient cells with wild-type ATG7 reestablished autophagy-mediated control of infection. Collectively, these data suggest that ATG7 defect contributes to host susceptibility to PV infection and propose autophagy as an unappreciated antiviral effector in viral infection in humans.

Host Genetics, Innate Immune Responses, and Cellular Death Pathways in Poliomyelitis Patients.

PURPOSE: Poliovirus (PV) is one of the most studied viruses. Despite efforts to understand PV infection within the host, fundamental questions remain unanswered. These include the mechanisms determining the progression to viremia, the pathogenesis of neuronal infection and paralysis in only a minority of patients. Because of the rare disease phenotype of paralytic poliomyelitis (PPM), we hypothesize that a genetic etiology may contribute to the disease course and outcome. METHODS: We used whole-exome sequencing (WES) to investigate the genetic profile of 18 patients with PPM. Functional analyses were performed on peripheral blood mononuclear cells (PBMCs) and monocyte-derived macrophages (MdMs). RESULTS: We identified rare variants in host genes involved in interferon signaling, viral replication, apoptosis, and autophagy. Upon PV infection of MdMs, we observed a tendency toward increased viral burden in patients compared to controls, suggesting reduced control of PV infection. In MdMs from patients, the IFNß response correlated with the viral burden. CONCLUSION: We suggest that genetic variants in innate immune defenses and cell death pathways contribute to the clinical presentation of PV infection. Importantly, this study is the first to uncover the genetic profile in patients with PPM combined with investigations of immune responses and viral burden in primary cells.

Neurological Symptoms in Danes with a History of Poliomyelitis: Lifelong Follow-Up of Late Symptoms, their Association with Initial Symptoms of Polio, and Presence of Postpolio Syndrome.

BACKGROUND: Previous studies suggest that patients with a history of poliomyelitis (PM) later in life experience a variety of symptoms. These studies were carried out in patients who later in life were admitted to hospital or became members of polio societies and may therefore not be representative of all polio patients. Little data have been published concerning patients actually discharged from hospital with a diagnosis of acute paralytic PM. OBJECTIVES: The aim of this study was to compare the prevalence of late symptoms in individuals with a history of paralytic PM with that of controls, and to study whether late symptoms in individuals with a history of PM were associated with symptoms at the acute stage of polio, and finally to compare the prevalence of symptoms in polio patients with postpolio syndrome (PPS) with the prevalence of symptoms in polio patients without PPS. METHODS: A questionnaire concerning various symptoms was sent to a previously established cohort of patients, who during the polio epidemics were discharged from the Department of Infectious Disease at Blegdamshospitalet, Copenhagen, with a diagnosis of paralytic PM, and to age- and gender-matched controls without PM. Information about symptoms at the acute stage of disease was obtained from hospital records. Logistic regression analysis with adjustment for age and gender was applied to compare the occurrence of late symptoms in cases and controls and within the above-mentioned groups of individuals with a history of PM. RESULTS: (i) Compared with controls, individuals with a history of polio significantly more often reported muscle symptoms, pain, neuropathic sensory symptoms, and bulbar symptoms; (ii) the occurrence of symptoms did not seem to be related to symptoms of the initial PM; and (iii) symptom prevalence was significantly higher in individuals with a history of polio who reported PPS as compared with those who did not. CONCLUSION: Our data indicate that individuals with a history of PM late in life experience a variety of symptoms that cannot be attributed to lesions of the anterior horn. Furthermore, late symptoms do not seem to be related to initial symptoms of the acute stage of PM but to reported PPS. The last finding supports the perception that the cause of PPS is not just normal ageing.

Long-term socio-economic consequences and health care costs of poliomyelitis: a historical cohort study involving 3606 polio patients.

Worldwide 10-20 million individuals are living with disabilities after acute poliomyelitis. However, very little is known about the socio-economic consequences and health care costs of poliomyelitis. We carried out a historical register-based study including 3606 individuals hospitalised for poliomyelitis in Copenhagen, Denmark 1940-1954, and 13,795 age and gender-matched Danes. Participants were followed from 1980 until 2012, and family, socio-economic conditions and health care costs were evaluated in different age groups using chi-squared tests, boot-strapped t tests or hazard ratios (HR) calculated in Cox-regression models. The analyses were performed separately for paralytic and non-paralytic polio survivors and their controls, respectively. Compared with controls a higher percentage of paralytic polio survivors remained childless, whereas no difference was observed for non-paralytic polio survivors. The educational level among paralytic as well as non-paralytic polio survivors was higher than that among their controls, employment rate at the ages of 40, 50 and 60 years was slightly lower, whereas total income in the age intervals of 31-40, 41-50 and 51-60 years were similar to controls. Paralytic and non-paralytic polio survivors had a 2.5 [HR = 2.52 (95 % confidence interval (CI); 2.29-2.77)] and 1.4 [HR = 1.35 (95 % CI; 1.23-1.49)]-fold higher risk, respectively, of receiving disability pension compared with controls. Personal health care costs were considerably higher in all age groups in both groups of polio survivors. Individuals with a history of poliomyelitis are well educated, have a slightly lower employment rate, an income similar to controls, but a considerably higher cost in the health care system.

[Polio, late effects and post-polio].

Approximately 7,000 Danes are still living with sequelae after surviving an acute polio infection. Late effects of polio include deformities, arthrosis and overloaded muscles. In the long run polio patients are at risk of having a further decrease of muscle function and a wide variety of other symptoms, a condition called post-polio syndrome (PPS). Treatment of PPS is in general symptomatic. Recently it has been shown that treatment with intravenous immunoglobulin may have an effect on pain, tiredness and walking distance. Patients with prior polio have an increase in morbidity and mortality, and may be more sensitive to a variety of medicine.

Factors that influence in vitro cholesterol deposition on contact lenses.

PURPOSE: The purpose of this study was to analyze the impact that incubation time, lipid concentration, and solution replenishment have on silicone hydrogel (SiHy) and conventional hydrogel (CH) contact lens cholesterol deposition via in vitro radiochemical experiments. METHODS: Four SiHy (senofilcon A, lotrafilcon B, comfilcon A, balafilcon A) and two CH (etafilcon A and omafilcon A) contact lenses were incubated in an artificial tear solution (ATS) that contained major tear film proteins, lipids, salts, salts, and a trace amount of radioactive C-cholesterol. Lenses were incubated for various incubation times (1, 3, 7, 14, or 28 days), with three concentrations of lipid (0.5×, 1×, 2× tear film concentration) and with or without solution replenishment to assess each variable's impact on cholesterol deposition. After incubation, the lenses were extracted using 2:1 chloroform:methanol, extracts were analyzed in a beta counter and masses (micrograms per lens) were extrapolated from standard curves. RESULTS: Within the SiHy materials, balafilcon A deposited the greatest amount of cholesterol (p < 0.001) and lotrafilcon B the lowest (p < 0.001). The CH lens materials showed significantly lower uptake amounts than any of the SiHy lens materials (p < 0.001). The uptake of cholesterol ranged from 0.01 ± 0.01 µg/lens to 3.22 ± 0.34 µg/lens for all lens materials. Kinetic uptake of cholesterol was shown to be continuous throughout the 28 days of incubation without plateau (p < 0.001), and varying the lipid concentration did impact the resulting cholesterol deposition (p < 0.001). Replenishing the ATS every other day also affected cholesterol deposition throughout the experiment. Overall, the deposition pattern was 2× > replenishing > 1× > 0.5×. CONCLUSIONS: Overall, SiHy lenses deposit significantly more cholesterol than CH lens materials, and the mass of lipid deposited is dependent on the contact lens material, length of incubation, concentration of lipids in the ATS, and the replenishment of ATS.

Bladder symptoms among polio survivors.

OBJECTIVE: To describe bladder symptoms among polio survivors and the inconvenience they cause. DESIGN: A survey using the validated Danish Prostatic Symptom Score questionnaire concerning bladder symptoms. SUBJECTS: A random age- and gender-stratified sample of polio survivors drawn from members of the Danish Society of Polio and Accident Victims. METHODS: Eligible subjects were sent the questionnaire by post. RESULTS: Of 453 eligible subjects 272 responded. Within 2 weeks 87.5% of respondents had experienced at least one bladder symptom, and 76.5% reported that they had been bothered by a bladder symptom. Out of the 12 symptoms in the questionnaire we found a significant gender difference, with straining and weak stream reported more often among men, and urge incontinence reported more often among women. Incontinence occurred significantly more often among women (73.3%) than among men (40.9%). Compared with a similar study of the background population, bladder symptoms overall occurred approximately twice as often among polio survivors. CONCLUSION: The majority of polio survivors experience bladder symptoms, prevalences being approximately twice as high as in the background population. Furthermore, polio survivors to a much larger extent find their bladder symptoms bothersome. A successful rehabilitation programme should therefore also focus on these symptoms.

Contact lens physical properties and lipid deposition in a novel characterized artificial tear solution.

PURPOSE: To characterize various properties of a physiologically-relevant artificial tear solution (ATS) containing a range of tear film components within a complex salt solution, and to measure contact lens parameters and lipid deposition of a variety of contact lens materials after incubation in this ATS. METHODS: A complex ATS was developed that contains a range of salts, proteins, lipids, mucin, and other tear film constituents in tear-film relevant concentrations. This ATS was tested to confirm that its pH, osmolality, surface tension, and homogeneity are similar to human tears and remain so throughout the material incubation process, for up to 4 weeks. To confirm that silicone hydrogel and conventional hydrogel contact lens materials do not alter in physical characteristics beyond what is allowed by the International Organization for Standardization (ISO) 18369-2. The diameter, center thickness, and calculated base curve were measured for five different lens materials directly out of the blister pack, after a rinse in saline and then following a two week incubation in the modified ATS. To test the ATS and the effect of its composition on lipid deposition, two lens materials were incubated in the ATS and a modified version for several time points. Both ATS solutions contained trace amounts of carbon-14 cholesterol and phosphatidylcholine, such that deposition of these specific lipids could be quantified using standard methods. RESULTS: This ATS is a complex mixture that remains stable at physiologically relevant pH (7.3-7.6), osmolality (304-306 mmol/kg), surface tension (40-46 dynes/cm) and homogeneity over an incubation period of three weeks or more. The physical parameters of the lenses tested showed no changes beyond that allowed by the ISO guidelines. Incubations with the ATS found that balafilcon A lenses deposit significantly more cholesterol and phosphatidylcholine than omafilcon A lenses (p<0.05) and that removing lactoferrin and immunoglobulin G from the ATS can significantly decrease the mass of lipid deposited. CONCLUSIONS: This paper describes a novel complex artificial tear solution specially designed for in-vial incubation of contact lens materials. This solution was stable and did not adversely affect the physical parameters of the soft contact lenses incubated within it and showed that lipid deposition was responsive to changes in ATS composition.

Gastrointestinal dysfunction in a community sample of subjects with symptoms of irritable bowel syndrome.

BACKGROUND/AIM: Irritable bowel syndrome (IBS) affects about 15-20% of the population of the Western countries. Traditionally, IBS has been an exclusion diagnosis, but recently definitions have emerged from population-based research. The aim of this population-based study was to evaluate any association between gastrointestinal pathophysiology and IBS in subjects with symptoms of IBS compared to subjects with no abdominal complaints. METHODS: From a random sample of 2,656 participants, subjects with IBS (32) together with subjects without abdominal complaints (26), were invited for further evaluation. IBS was defined as more than weekly experience of abdominal pain and distension, and in addition either borborygmia or altering stool consistency. The diagnostic work-up consisted of gastroscopy, manometry and 23-hour pH and pressure recordings of the oesophagus, lactose tolerance test, barium enema, measurement of colonic transit time, and rectoscopy. RESULTS: Compared to the group without abdominal complaints significantly more subjects with IBS had spasms of the colon (OR = 10.2 (1.2-87.3)), and abnormal contractions of the oesophagus at manometry (OR = 9.1 (1.1-78.2)). Furthermore, there was a non-significant tendency towards spasms at 23-hour pH and pressure recordings (OR = 3.58 (0.4-35.2)), and more discomfort at lactose tolerance test (OR = 5.8 (0.6-51.3)) in persons with IBS compared to subjects without abdominal complaints. CONCLUSION: The results of this population-based study indicate that signs of gastrointestinal dysmotility and hyperperception are more prevalent in subjects with IBS than in subjects without abdominal complaints.