Rate of flow of aqueous humor determined from measurements of aqueous flare

Measurement of light scattered in the anterior chamber can provide important clinical information about the eye. In this study, a scanning ocular spectrofluorophotometer was used to measure scattering in the anterior chamber. Pathologic scattering (flare) was induced by argon laser photocoagulation of the iris in pigmented rabbits. The spectrally corrected intensity of the flare in inflamed eyes decreased as the inverse 2.2 power of the wavelength of the illuminating beam. The strongest signal with this instrument was measured at 470 nm. Diurnal variation of normal and spontaneous scatter from the aqueous humor was measured in nine pigmented rabbits entrained to a 12-hr light/12-hr dark cycle and in eight human subjects. A technique is described for determining the rate of flow of aqueous humor from scattered light when the transfer rate of scattering substance into the anterior chamber is constant. This technique was used to study changes in flow over the diurnal cycle. The rate of flow in human subjects during sleep was 60% of the rate during waking hours. In rabbits, the rate was lowest (44% of maximum) during the 6 hr after the lights were turned on, and were greatest just before the lights were turned on. These findings confirm previous studies of the circadian rhythm of aqueous humor flow in rabbits and humans.     

Analysis of signal-to-noise behavior in Cartesian continuous sampling sequences: predictions and experimental validation of opportunities for improved image SNR.

Image signal-to-noise ratio (SNR) limits many MRI applications. Here we propose a method to improve SNR based on continuous sampling (CS) during each TR without significant increases in acquisition time. The general concept of CS is defined here as sampling the NMR signal immediately after slice excitation including ramp times, both the dephase and rephase lobes, the phase-encoding (PE) gradient application, and the slice refocusing gradient. This study analyzes several cases of CS and demonstrates a specific case where sampling occurs during an isolated and balanced readout gradient in order to increase SNR in a rectilinear Cartesian sequence without significantly increasing overall acquisition time. The noise correlation consequences of rectilinear CS are mathematically derived and proven through simulation. The SNR improvement of up to approximately 40% measured in both phantom and asymptomatic human volunteer images is comparable to theoretical prediction of increased SNR proportional to the increase in the square root of the sampling time.     

Global molecular epidemiology of the O15:K52:H1 extraintestinal pathogenic Escherichia coli clonal group: evidence of distribution beyond Europe

Escherichia coli O15:K52:H1 is a significant extraintestinal pathogen in Europe (G. Prats et al., J. Clin. Microbiol. 38:201-209, 2000). To search for evidence of this clonal group outside of Europe, 75 non-European E. coli isolates of serogroup O15 were compared with five members of the O15:K52:H1 clonal group from Barcelona, Spain, according to genomic background, virulence genotypes, and antimicrobial resistance profiles. Amplification phylotyping showed that 16 (21%) of the 75 non-European O15 isolates corresponded with the O15:K52:H1 clonal group. The 16 non-European O15:K52:H1 clonal group members represented diverse geographic locales. They were isolated almost exclusively from humans with extraintestinal infections and accounted for 50% of all O15 isolates from five human clinical collections studied. Most non-European clonal group members exhibited a consensus virulence factor profile that included the F16 or F7-2 papA alleles (P fimbrial structural subunit), papG allele II (P fimbrial adhesin), iha (putative adhesin siderophore), and iutA (aerobactin receptor). This resembles the virulence profiles of (i) European representatives of the O15:K52:H1 clonal group and (ii) phylogenetically related "clonal group A," a recently recognized significant contributor to trimethoprim-sulfamethoxazole resistance in the United States (A. R. Manges et al., N. Engl. J. Med. 345:1007-1013, 2001). Antimicrobial resistance profiles were variable, and resistance was inconsistently transferred by conjugation. These findings indicate that the O15:K52:H1 clonal group is broadly distributed beyond Europe, exhibits previously unrecognized phenotypic and genotypic diversity, and contributes significantly to extraintestinal infections in humans.     

Preterm Birth Among US and Foreign-Born Non-Hispanic Black Birthing Parents in Massachusetts: Variation by Nativity,Region, and Country of Origin

Maternal and Child Health Journal - Foreign-born non-Hispanic Black (NHB) birthing parents are less likely to have a preterm birth (PTB) than US-born NHBs. There is further variation by region and...     

ASO Visual Abstract: Chemotherapy After Diagnosis of Malignant Bowel Obstruction is Associated with Greater Survival for Medicare Patients with Advanced Malignancy

Annals of Surgical Oncology -     

COVID-19 Treatment: Drug Safety Prior to Conception and During Pregnancy and Breastfeeding

In December 2019, a new viral respiratory infection known as coronavirus disease 2019 (COVID-19) was first diagnosed in the city of Wuhan, China. COVID-19 quickly spread across the world, leading the World Health Organization to declare it a pandemic on March 11, 2020. The disease is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a similar virus to those involved in other epidemics such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). Epidemiological studies have shown that COVID-19 frequently affects young adults of reproductive age and that the elderly and patients with chronic disease have high mortality rates. Little is known about the impact of COVID-19 on pregnancy and breastfeeding. Most COVID-19 cases present with mild flu-like symptoms and only require treatment with symptomatic relief medications, whereas other cases with COVID-19 require treatment in an intensive care unit. There is currently no specific effective treatment for COVID-19. A large number of drugs are being used to fight infection by SARS-CoV-2. Experience with this therapeutic arsenal has been gained over the years in the treatment of other viral, autoimmune, parasitic, and bacterial diseases. Importantly, the search for an effective treatment for COVID-19 cannot expose pregnant women infected with SARS-CoV-2 to the potential teratogenic risks of these drugs. Therefore, it is necessary to determine and understand the safety of anti-COVID-19 therapies prior to conception and during pregnancy and breastfeeding.Key words: COVID-19, SARS-CoV-2, antiviral, pregnancy, breastfeeding     

Ocular manifestations of immunological and rheumatological inflammatory disorders

Our understanding of ocular manifestations in immunological and rheumatological inflammatory disorders has continued to expand over the past year. A report on the characteristics of ocular disease in children with Beh?et's disease is presented. Two reports of Vogt-Koyanagi-Harada syndrome in 4-year-old children are discussed, and the uncommon complication of macular edema in this syndrome is highlighted. An article reporting the presence of Epstein-Barr virus DNA in the vitreous of a patient with Vogt-Koyanagi-Harada syndrome is reviewed. Radiologic imaging patterns of orbital disease in Wegener's granulomatosis are presented. Unusual manifestations of sarcoidosis, systemic lupus erythematosus, and Wegener's granulomatosis are also reported.