Social Network Characteristics Associated with More Frequent HIV and STI Prevention Conversations: The N2 Cohort Study in Chicago.

Black cisgender sexually minoritized men (SMM) and transgender women (TW) are subgroups at highest risk of HIV and sexually transmitted infections (STIs) in the US. We sought to identify factors facilitating continued conversations - social reinforcement - surrounding HIV/STI prevention among this subgroup. Participants were recruited in Chicago from 2018 to 2019 from community health spaces. Participants provided information about themselves (level 2) and ⩽5 confidants (level 1). We used multinomial multilevel modeling to identify associations with HIV/STI prevention conversation frequency. A total of 370 participants provided information on 987 confidants (mean = 2.6). We found significantly positive associations between having biweekly or more often HIV/STI prevention conversations and a confidant being a kin family member, older by 15 years or more, racially homophilous, and emotionally close. Future interventions should harness social networks by including components that consider racial homophily, respect for elders, and strong ties, in addition to applying kin family systems interventions approaches and decreasing stigma surrounding HIV/STIs.

A qualitative and quantitative assessment of the impact of three processing algorithms with halving of study count statistics in myocardial perfusion imaging: filtered backprojection, maximal likelihood expectation maximisation and ordered subset expectation maximisation with resolution recovery.

INTRODUCTION: Ordered subset expectation maximisation with depth-dependent resolution recovery (OSEM-RR) is a processing algorithm reported to improve images with halved tracer activity in myocardial perfusion scintigraphy (MPS) compared to filtered backprojection (FBP) using conventional activities. OSEM-RR has not yet been compared with maximal likelihood expectation maximisation (MLEM). METHODS: 39 patients undergoing MPS and two anthropomorphic phantoms (one with, one without an inferior wall insert) had full-time (FT) and half-time (HT) SPECT datasets acquired simultaneously and processed by FBP, MLEM and OSEM-RR. Two experienced reporters scored images of all clinical studies (n=234) for conspicuity of a perfusion defect, with results being compared using Wilcoxon paired and Kappa tests. A quantitative assessment based on mean segmental pixel counts taken from numbers automatically displayed over the 20 segments of Cedars Sinai Autoquant QPS image were compared using Pearson's correlation and Bland Altman analysis. RESULTS: A small but consistent superior concurrence between FT and HT datasets for OSEM-RR compared to FBP and MLEM was observed for both qualitative and quantitative analyses. OSEM-RR resulted in better definition of the inferior wall defect on the phantom study. CONCLUSION: OSEM-RR appears superior to both FBP and MLEM in terms of handling reduced count statistics.

A Gas Pressure Scale Based on Primary Standard Piston Gauges.

The National Institute of Standards and Technology (NIST) has redefined its gas pressure scale, up to 17 MPa, based on two primary standard piston gauges. The primary standard piston gauges are 35.8 mm in diameter and operate from 20 kPa to 1 MPa. Ten secondary standard piston gauges, two each of five series of the Ruska 2465 type, with successively smaller diameters form the scale extending up to 17 MPa. Six of the piston gauges were directly compared to the primary standards to determine their effective area and expanded (k = 2) uncertainty. Two piston gauges operating to 7 MPa were compared to the 1.4 MPa gauges, and two piston gauges operating to 17 MPa were compared to the 7 MPa gauges. Distortion in the 7 MPa piston gauges was determined by comparing those gauges to a DH Instruments PG7601 type piston gauge, whose distortion was calculated using elasticity theory. The relative standard uncertainties achieved by the primary standards range from 3.0 × 10(-6) to 3.2 × 10(-6). The relative standard uncertainty of the secondary standards is as low as 4.2 × 10(-6) at 300 kPa. The effective areas and uncertainties were validated by comparison to standards of other National Metrology Institutes (NMIs). Results show agreement in all cases to better than the expanded (k = 2) uncertainty of the difference between NIST and the other NMIs, and in most cases to better than the standard (k = 1) uncertainty of the difference.

Design, synthesis, and biological evaluation of aryl piperazines with potential as antidiabetic agents via the stimulation of glucose uptake and inhibition of NADH:ubiquinone oxidoreductase.

The management of blood glucose levels and the avoidance of diabetic hyperglycemia are common objectives of many therapies in the treatment of diabetes. An aryl piperazine compound 3a (RTC1) has been described as a promoter of glucose uptake, in part through a cellular mechanism that involves inhibition of NADH:ubiquinone oxidoreductase. We report herein the synthesis of 41 derivatives of 3a (RTC1) and a systematic structure-activity-relationship study where a number of compounds were shown to effectively stimulate glucose uptake in vitro and inhibit NADH:ubiquinone oxidoreductase. The hit compound 3a (RTC1) remained the most efficacious with a 2.57 fold increase in glucose uptake compared to vehicle control and micromolar inhibition of NADH:ubiquinone oxidoreductase (IC50 = 27 µM). In vitro DMPK and in vivo PK studies are also described, where results suggest that 3a (RTC1) would not be expected to provoke adverse drug-drug interactions, yet be readily metabolised, avoid rapid excretion, with a short half-life, and have good tissue distribution. The overall results indicate that aryl piperazines, and 3a (RTC1) in particular, have potential as effective agents for the treatment of diabetes.

Cardiovascular disease in peritoneal dialysis patients.

Patients on peritoneal dialysis have a high level of morbidity and mortality associated with atherosclerotic cardiovascular disease and they also have an increased risk of sudden death. The atherosclerosis seen in peritoneal dialysis patients is associated with both traditional cardiovascular risk factors such as low levels of physical activity, hyperlipidemia, hypertension, diabetes and smoking as well as non-traditional risk factors such as elevated oxidative stress and inflammation. The atherosclerosis may be preceded by endothelial dysfunction and increased arterial stiffness. Measures of arterial stiffness such as aortic pulse wave velocity predict morbidity and mortality. Numerous studies have reported that the elevated levels of oxidative stress and inflammation in this population are associated with arterial stiffness and in turn with the development of cardiovascular disease. A number of studies have reported that peritoneal dialysis is associated with lower levels of oxidative stress and inflammation compared to haemodialysis. A small number of trials have extended this work to determine associations between oxidative stress and inflammation with vascular or myocardial structure and function with equivocal results. The decision to undergo either peritoneal or haemodialysis is based on many factors which include the differential damage the renal replacement therapy may have on the cardiovascular system. Current evidence suggests this may vary over time. Previous randomised controlled trials and many other observational studies have produced conflicting results as to which therapy may have a cardiovascular advantage. Some registry data suggests peritoneal dialysis is associated with a lower mortality than haemodialysis in the first one-two years but thereafter may be higher on peritoneal dialysis than haemodialysis. Other registry data do not support this. Further long-term studies assessing surrogate and hard endpoint cardiovascular outcomes in peritoneal dialysis are required.

Automated Piston Gauge Calibration System.

Piston gauges or pressure balances are important primary standards for the realization of the SI unit of pressure, the pascal. Because of their long-term stability, they are also used as secondary or working standards in the dissemination of the pressure scale. The National Institute of Standards and Technology (NIST) operates and maintains a calibration service for these devices, and has recently undertaken a modernization effort. Following a preliminary investigation into the feasibility of using transducers as instantaneous in-situ transfer standards, we now present the results of a near fully automated calibration system. This effort includes the design, building, and validation of an automated gas-handling manifold, and the development of a new software suite. The new system demonstrates an expanded uncertainty on the order of 1 in 105, comparable to the traditional system, but offers a five-fold decrease in calibration turnaround time.

Pressure balance cross-calibration method using a pressure transducer as transfer standard.

Piston gauges or pressure balances are widely used to realize the SI unit of pressure, the pascal, and to calibrate pressure sensing devices. However, their calibration is time consuming and requires a lot of technical expertise. In this paper, we propose an alternate method of performing a piston gauge cross calibration that incorporates a pressure transducer as an immediate in-situ transfer standard. For a sufficiently linear transducer, the requirement to exactly balance the weights on the two pressure gauges under consideration is greatly relaxed. Our results indicate that this method can be employed without a significant increase in measurement uncertainty. Indeed, in the test case explored here, our results agreed with the traditional method within standard uncertainty, which was less than 6 parts per million.

The Peterborough scheme for community specialist optometrists in glaucoma: a feasibility study.

PURPOSE: This study assessed the role of specialist optometrists who were working in the community and sharing the care for glaucoma patients with, and under close supervision of, a consultant ophthalmologist working in the Hospital Eye Services (HES) to ensure high-quality standards, safety, and care. METHODS: From February 2005 onwards, the majority of all new glaucoma referrals to our eye department were diverted to our specialist optometrists in glaucoma (SOGs) in their own community practices. Selected patients in the HES setting who were already diagnosed with stable glaucoma were also transferred to the SOGs. The completed clinical finding details of the SOGs, including fundus photographs and Humphrey visual field tests, were scrutinised by the project lead. RESULTS: This study included 1184 new patients seen by specialist optometrists between February 2005 and March 2007. A total of 32% of patients were referred on to the hospital, leaving the remaining 68% patients to be seen for at least their next consultation in the community by the SOGs. The following levels of disagreement were observed between SOGs and the project lead: on cup:disc ratio (11%), visual field interpretation (7%), diagnosis (12%), treatment plan (10%), and outcome (follow-up interval and location) (17%). CONCLUSION: This study indicates that there is potential for a significant increase in the role of primary care optometry in glaucoma management. The study also confirms a need for a significant element of supervision and advice from a glaucoma specialist. The important issue of cost effectiveness is yet to be confirmed.

Insulin allergy in a patient with Type 2 diabetes successfully treated with continuous subcutaneous insulin infusion.

BACKGROUND: Patients with poor control of Type 2 diabetes on maximum oral hypoglycaemic therapy invariably need insulin therapy. Insulin allergy is uncommon, particularly in patients with Type 2 diabetes. Management of the condition can be difficult, and here we report the case of a patient with Type 2 diabetes and insulin allergy successfully managed with a continuous subcutaneous insulin infusion (CSII). CASE REPORT: A 60-year-old man was referred with insulin allergy. He had poorly controlled Type 2 diabetes (glycated haemoglobin 10.4%), on maximum doses of sulphonylurea and metformin, with osmotic symptoms. He was compliant with diet and tablets. His diabetes was complicated by retinopathy, nephropathy, coronary heart disease, obstructive sleep apnoea, obesity, depression and hypertension. He commenced on twice daily mixed insulin and, shortly after, developed pain, itching and erythema at the injection sites. The sites became indurated and tender, and he had constitutional symptoms. The insulin was changed to other preparations, including short- and long-acting analogues, with similar responses. Triple therapy with rosiglitazone was tried, with no improvement in control. Skin-prick testing confirmed allergy to insulin rather than additives. The patient was reluctant to undergo desensitization. He was commenced on an insulin pump in addition to his oral hypoglycaemics, and achieved fair control (glycated haemoglobin 8.3%) on 88 units of lispro per day, with little or no skin or systemic reaction. CONCLUSION: This is the first case report of insulin allergy in Type 2 diabetes being successfully managed by CSII.

Physical analysis of deletion mutations in the ilvGEDA operon of Escherichia coli K-12.

DNA-DNA hybridization of cloned segments of the Escherichia coli K-12 ilvGEDA operon to genomic blots was used to determine the physical dimensions of a series of deletion mutations of the ilvGEDA operon. The smallest mutation resulted from the deletion of approximately 200 base pairs from within ilvD, whereas the largest mutation resulted from the deletion of 17 kilobases including the rep gene. The structure of three of these mutants indicates that formation of the deletions was mediated by Tn5 (or Tn5-131) that is retained in the chromosome. This is the first observation of this type of Tn5-mediated event. Our analysis of the total acetohydroxy acid synthase activity of strains containing deletions of ilvG indicates that the truncated ilvG polypeptide of wild-type E. coli K-12 lacks enzyme activity. The small 200-base-pair deletion of ilvD confirms the presence of a strong polar site 5' to ilvA. The detailed structure of these deletions should prove useful for the investigation of other genes in this region. This genomic analysis demonstrates that the ilv restriction site map that was established previously by the analysis of recombinant bacteriophage and plasmids is identical to that on the genome.

Restriction endonuclease analysis of the ilvGEDA operon of members of the family Enterobacteriaceae.

Four of the genes required for the biosynthesis of isoleucine and valine form the ilvGEDA operon in Escherichia coli K-12 and Salmonella typhimurium. The structural relationship of these genes was examined in eight other members of the family Enterobacteriaceae by genomic Southern blot hybridization. These genes are contiguous in all the strains examined, and specific restriction sites appear to be highly conserved, indicating the possible functional importance of the DNA sequences of which they are part.

Photoionization cross sections of metal vapors below 50 nm: an apparatus for their measurement.

An apparatus built for the measurement of photoionization cross sections of metallic vapors in the 30-100-nm wavelength region is described. The performance was tested by measurements of cross sections in the region of the window resonances in argon. Results in agreement with those of Madden, Codling, and Ederer were obtained.