Engineering digital biomarkers of interstitial glucose from noninvasive smartwatches

Prediabetes affects one in three people and has a 10% annual conversion rate to type 2 diabetes without lifestyle or medical interventions. Management of glycemic health is essential to prevent progression to type 2 diabetes. However, there is currently no commercially-available and noninvasive method for monitoring glycemic health to aid in self-management of prediabetes. There is a critical need for innovative, practical strategies to improve monitoring and management of glycemic health. In this study, using a dataset of 25,000 simultaneous interstitial glucose and noninvasive wearable smartwatch measurements, we demonstrated the feasibility of using noninvasive and widely accessible methods, including smartwatches and food logs recorded over 10 days, to continuously detect personalized glucose deviations and to predict the exact interstitial glucose value in real time with up to 84% and 87% accuracy, respectively. We also establish methods for designing variables using data-driven and domain-driven methods from noninvasive wearables toward interstitial glucose prediction.

Non-invasive wearables for remote monitoring of HbA1c and glucose variability: proof of concept

INTRODUCTION

Diabetes prevalence continues to grow and there remains a significant diagnostic gap in one-third of the US population that has pre-diabetes. Innovative, practical strategies to improve monitoring of glycemic health are desperately needed. In this proof-of-concept study, we explore the relationship between non-invasive wearables and glycemic metrics and demonstrate the feasibility of using non-invasive wearables to estimate glycemic metrics, including hemoglobin A1c (HbA1c) and glucose variability metrics.

RESEARCH DESIGN AND METHODS

We recorded over 25 000 measurements from a continuous glucose monitor (CGM) with simultaneous wrist-worn wearable (skin temperature, electrodermal activity, heart rate, and accelerometry sensors) data over 8-10 days in 16 participants with normal glycemic state and pre-diabetes (HbA1c 5.2-6.4). We used data from the wearable to develop machine learning models to predict HbA1c recorded on day 0 and glucose variability calculated from the CGM. We tested the accuracy of the HbA1c model on a retrospective, external validation cohort of 10 additional participants and compared results against CGM-based HbA1c estimation models.

RESULTS

A total of 250 days of data from 26 participants were collected. Out of the 27 models of glucose variability metrics that we developed using non-invasive wearables, 11 of the models achieved high accuracy (<10% mean average per cent error, MAPE). Our HbA1c estimation model using non-invasive wearables data achieved MAPE of 5.1% on an external validation cohort. The ranking of wearable sensor's importance in estimating HbA1c was skin temperature (33%), electrodermal activity (28%), accelerometry (25%), and heart rate (14%).

CONCLUSIONS

This study demonstrates the feasibility of using non-invasive wearables to estimate glucose variability metrics and HbA1c for glycemic monitoring and investigates the relationship between non-invasive wearables and the glycemic metrics of glucose variability and HbA1c. The methods used in this study can be used to inform future studies confirming the results of this proof-of-concept study.

SAT-414 A Single Center Retrospective Analysis and Review of Endocrinopathies from Immune Checkpoint Inhibitors Between 2007 and 2017

Immune checkpoint inhibitors (ICI) specifically target and dysregulate immune tolerance. As a result of this immune activation, immune related adverse events (irAEs) are common. These can include endocrinopathies like immune hypophysitis (IH), primary adrenal insufficiency (PAI), autoimmune thyroid disease, Graves disease and type 1 Diabetes Mellitus (T1DM)[1]. The aim of this retrospective review was to describe the prevalence, timing, and clinical characteristics of ICI-related endocrinopathies at our institution. Methods: A retrospective chart review was conducted for all patients between January 01, 2007 and February 01, 2017 who met predefined clinical, biochemical and imaging criteria for endocrinopathies including IH, T1DM, autoimmune thyroid disease, Graves disease and PAI. Results: Among 690 patients who received ICPI during the study period, 91 unique patients with complete data developed endocrinopathies, for an overall prevalence of 13%. The study included 50 (55%) men and 41 (45%) women with a median age of 64 years (range 20-96 years). Grade 2 endocrinopathies were reported more commonly (n=49, 54%); grade 3/4 events were rare (15%). Among the ICIs, Nivolumab was the most common ICI noted for study patients (n=51, 56%). Autoimmune thyroid disease was the most common irAE in our study (n= 63, 9.1% overall prevalence). We also report 25 cases of IH (3.6%), 2 cases of PAI (0.3%) and 1 case of Graves disease (0.1%). Most patients with autoimmune thyroid disease developed subclinical hypothyroidism (n=26, 3.8%) and overt hyperthyroidism (n=21, 3.0%). We note a high median TSH of 67.3 µIU/mL; range- 20.6-111.0 in overt hypothyroidism compared to subclinical hypothyroidism (14.0 µIU/mL; range- 5.6-100 µIU/mL). Overall, median time to developing any endocrinopathy after initiating ICI was 13.7 weeks; range- 0.7-351.5 weeks. Among the subjects who developed IH, the median TSH was 0.37 µIU/mL (0.01 - 62.39 µIU/mL) with a free T4 of 0.74 ng/dL (0.25-1.86 ng/dL) and the median cortisol was 0.80 µg/dL (0.25-24.5 µg/dL). Amongst the IH group, 17 patients developed isolated secondary adrenal insufficiency and 8 patients developed combination of other hormone deficiencies with secondary AI including 6 with secondary hypothyroidism, 1 patient with hypogonadotropic hypogonadism and 1 with hypothyroidism and hypogonadism in addition to secondary AI. Despite development of irAEs, ICI therapy was continued in 59 pts (65%) who developed an endocrine irAE. Conclusions: In summary, this is one of the largest single institution retrospective studies on ICI related endocrinopathies. The majority of endocrinopathies were low grade, and most patients continued ICI treatment. Reference: Barroso-Sousa, Romualdo. Incidence of Endocrine Dysfunction Following the Use of Different Immune Checkpoint Inhibitor Regimens: A Systematic Review and Meta-analysis. JAMA, Sept 2017

Caenorhabditis elegans dpy-5 is a cuticle procollagen processed by a proprotein convertase

Genetic analysis of the nematode Caenorhabditis elegans reveals that all dpy-5 alleles are dominant suppressors of bli-4 blistering. Molecular cloning of dpy-5 establishes that it encodes a cuticle procollagen, defects in which are responsible for the short-body, dumpy phenotype. The null mutation, e907 removes the entire coding region, whereas the dpy-5 reference allele, e61, contains a nonsense substitution. RT-PCR analysis and a dpy-5::gfp fusion show that dpy-5 is expressed only in hypodermal cells at all post-embryonic life-cycle stages. Variable expression of dpy-5 in V lineage-derived seam cells suggests an alternative regulatory mechanism in these cells. The dpy-5 gene product contains an Arg-X-X-Arg cleavage motif that could be recognized by a proprotein convertase, such as BLI-4. Mutation of this site cause a dominant dumpy phenotype suggesting Dpy-5 procollagen requires processing for normal cuticle production.

Mutational analysis of bli-4/kpc-4 reveals critical residues required for proprotein convertase function in C. elegans

Kex2/subtilisin-like proteinase activity is required for the production of the adult cuticle in the nematode Caenorhabditis elegans. Deletion of the carboxy termini of four of the bli-4/kpc-4 convertase isoforms results in blistering of the adult cuticle. The blisters vary in severity (expressivity) and are not evident in all individuals (reduced penetrance). We have isolated 13 bli-4/kpc-4 mutants that arrest development in late embryogenesis. Using a PCR-based heteroduplex technique, we have identified nucleotide changes responsible for eight of these lethal mutations. The lesions reside within the first 12 exons that are shared by all of the bli-4/kpc-4 gene products, with the majority of mutations clustered within the protease domain. This finding suggests that the protease domain represents a large mutable target. Among these mutations, allele h384 represents a molecular null mutant in which the catalytically essential serine residue (Ser415) is replaced by phenylalanine. Novel missense mutations that change the identity of amino acids evolutionary conserved in all kex2/subtilisin-convertases highlight critical residues essential for activity. We examined the functional activity of BLI-4/KPC-4 products expressed from several lethal mutants by testing their effect on the variable penetrance of blistering exhibited by the e937 allele. We found that the combination of a bli-4/kpc-4 lethal mutation in trans to the bli-4(e937) mutation was sufficient to cause severe blistering in heteroallelic progeny, even in the presence of a known dominant suppressor.

A look at the Caenorhabditis elegans Kex2/Subtilisin-like proprotein convertase family

Significant advances have recently been made in our understanding of the mechanisms of activation of proteins that require processing. Often this involves endoproteolytic cleavage of precursor forms at basic residues, and is carried out by a group of serine endoproteinases, termed the proprotein convertases. In mammals, seven different convertases have been identified to date. These act in both the regulated secretory pathway for the processing of prohormones and proneuropeptides and in the constitutive secretory pathway, in which a variety of proproteins are activated endoproteolytically. The recently completed sequence of the nematode Caenorhabditis elegans genome affords a unique opportunity to examine the entire proprotein convertase family in a multicellular organism. Here we review the nature of the family, emphasising the structural features, characteristic of the four nematode genes, that supply all of the necessary functions unique to this group of serine endoproteinases. Studies of the C. elegans genes not only provide important information about the evaluation of this gene family but should help to illuminate the roles of these proteins in mammalian systems. BioEssays 22:545-553, 2000.

Functional genomics in Caenorhabditis elegans: An approach involving comparisons of sequences from related nematodes

Comparative genomic analysis was used to investigate the gene structure of the bli-4 locus from two related Caenorhabditis species, C. elegans and C. briggsae. In C. elegans, bli-4 is a complex gene encoding a member of the kex2/subtilisin-like family of proprotein convertases. Genomic sequence comparisons coupled with RT-PCR analysis identified five additional coding exons that had not been identified previously using standard recombinant DNA techniques. The C. briggsae gene was able to rescue both viable blistered and developmentally arrested mutants of C. elegans bli-4, demonstrating functional conservation. In addition, deletion analysis of conserved sequences outside of coding regions, combined with phenotypic rescue experiments, identified regulatory elements that alter the expression of the bli-4 gene. These results demonstrate the utility of genomic sequence comparisons of homologous genes in related species as an effective tool with which to dissect the functional information of complex genes.

Quinolone-resistant Neisseria gonorrhoeae isolated in Sydney, Australia, 1991 to 1995

BACKGROUND AND OBJECTIVES

Quinolone antibiotics are used widely for the treatment of gonorrhea, but resistant strains appeared in Sydney in 1984, treatment failure with high-dose regimens in 1991, and isolates with very high minimal inhibitory concentrations (MICs) (16 mg/l) in 1994.

GOALS

To examine the frequency, source, and characteristics of Quinolone-resistant Neisseria gonorrhoeae (QRNG) in Sydney from 1991 to 1995 and to compare these data with those obtained from 1984 to 1990.

STUDY DESIGN

The antibiotic sensitivity, auxotype-serovar class, and geographic source of QRNG isolated in Sydney from January 1, 1991 to June 30, 1995 were analyzed.

RESULTS

One hundred seven QRNG were isolated from 97 patients from 1991 to 1995. The number, proportion, and MICs of QRNG increased slowly in the first 4 years of the study and rapidly in the last 6 months. Most QRNG were isolated from travelers entering Sydney from Asia. Twenty-seven different auxotype-serovar classes were detected including 6 auxotype-serovar classes in 14 isolates with high-level quinolone resistance (MIC, 16 mg/l).

CONCLUSIONS

QRNG isolated in Sydney during the past decade originated in Asia as multiple gonococcal subtypes and increased substantially in numbers and levels of resistance in 1995.

High-level quinolone resistance in Neisseria gonorrhoeae: a report of two cases

BACKGROUND AND OBJECTIVES

Fluoroquinolones are widely used oral agents for treating Neisseria gonorrhoeae. Resistance to these agents is sporadic and usually at a low level. Two instances of high-dose ciprofloxacin regimens failing in the treatment of gonococcal infection, caused by strains with high-level quinolone resistance, are reported.

STUDY DESIGN

This is a case report.

CONCLUSION

High-level resistance to quinolone antibiotics resulting in treatment failure was observed in two distinct gonococcal isolates from patients infected in the Philippines (ciprofloxacin; minimal inhibitory contribution = 16 mg/l). Continued monitoring of the quinolone sensitivity of Neisseria gonorrhoeae is appropriate and prudent.

The bli-4 locus of Caenorhabditis elegans encodes structurally distinct kex2/subtilisin-like endoproteases essential for early development and adult morphology

Many secreted proteins are excised from inactive proproteins by cleavage at pairs of basic residues. Recent studies have identified several serine endoproteases that catalyze this cleavage in the secretory pathways of yeast and metazoans. These enzymes belong to the kex2/subtilisin-like family of proprotein convertases. In this paper we describe the molecular characterization of the bli-4 gene from Caenorhabditis elegans, which was shown previously by genetic analysis of lethal mutants to be essential for the normal development of this organism. Sequencing of cDNA and genomic clones has revealed that bli-4 encodes gene products related to the kex2/subtilisin-like family of proprotein convertases. Analysis of bli-4 cDNAs has predicted four protein products, which we have designated blisterases A, B, C, and D. These protein products share a common amino terminus, but differ at the carboxyl termini, and are most likely produced from alternatively spliced transcripts. We have determined the molecular lesions for three bli-4 alleles (h199, h1010, and q508) that result in developmental arrest during late embryogenesis. In each case, the molecular lesions are within exons common to all of the BLI-4 isoforms. The original defining allele of bli-4, e937, is completely viable yet exhibits blistering of the adult cuticle. Molecular analysis of this allele revealed a deletion that removes exon 13, which is unique to blisterase A. No RNA transcript corresponding to exon 13 is detectable in the blistered mutants. These findings suggest that blisterase A is required for the normal function of the adult cuticle.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of the Denham knee replacement. Results after eight years

The Denham knee replacement is a relatively simple unconstrained prosthesis. The design ensures good alignment and full extension, but does not allow flexion beyond 90 degrees or tibiofemoral rotation. The results after eight years' experience have been assessed in four different ways in over 600 cases. They show that for the limited needs of the elderly arthritic patient, the Denham arthroplasty provides a high proportion of satisfactory results with an unusually low rate of late failure.

Staphylococcus aureus Growth and Thermostable Nuclease and Enterotoxin Production in Canned Salmon and Sardines

Staphylococcus aureus growth, thermostable nuclease (TNase) and enterotoxin production in inoculated canned salmon incubated at 22 ± 1°C for 4 d were dependent on the size of inoculum, and on the amount of oxygen present in the headspace; under nitrogen with an inoculum of 7 cfu/can, 10²-10³ cfu/g, no TNase and traces of enterotoxins (A, B, C₂) were observed; under oxygen with the same inoculum ≥10⁹ cfu/g, ≥6.0 μg TNase and up to 5.2 μg total enterotoxins (A, B, and C₂)/100 g of salmon were observed. Values were intermediate under atmospheric air. After 1 week, 2 months and 4-24 months of incubation of salmon under nitrogen, S. aureus cfus were 10⁸, 10⁶ and 10⁴-10⁵ per g; TNase ranged from trace amounts to 20 μg/100 g and total enterotoxins from <1.0 μg to 6.2 μg/100 g. In canned sardines stored from 1 d to 12 months at 22 ± 1°C, levels were 10⁹ cfu/g and 3.7-3.9 μg total enterotoxins/100 g; after 1 week, counts declined to 10⁵ cfu/g but total enterotoxins remained relatively stable in some cans with up to 6.2 μg/100 g of sardines after 12 months. TNase varied from <1.0 μg to 20 μg/100 g of salmon with 10⁹ and 10⁵ cfu/g, respectively. In sardines, similar variation in TNase was observed and there was no correlation between TNase, enterotoxins and cfu/g. After 2 d to 24 months, carbon dioxide, an acidic smell and unacceptable odors were detectable over the headspace of S. aureus contaminated salmon and sardines, but not all persons who sniffed the contaminated products could recognize off-odors that would warn them against consuming the food. To prevent canned foods from causing staphylococcal illness, the conditions allowing post-process contamination should be eliminated by the producer and distributor of the products.

Reduction of Salmonella Excretion into Drinking Water Following Treatment of Chicks with Nurmi Culture

Day-old chicks ( Gallus domesticus ) were treated with cultured feces of adult chickens according to the Nurmi concept and were challenged 2 days later with Salmonella typhimurium . Treated chicks were less susceptible to infection than untreated chicks (16% vs. 79% infected). Those treated chicks that did become infected, contaminated their drinking water with fewer Salmonella than the untreated chicks (maximum of 10⁴/ml vs. ⩾ 10⁷/ml). Fecally contaminated water may be a major source for spreading Salmonella infection within a flock.

Simple Method for Anaerobic Inoculation of Foods in Cans, Retort Pouches, Glass Jars or Semi-Rigid Containers

Cured silicon sealant (SS) on lids of cans and glass jars, on retort pouch and semi-rigid container surfaces was employed for providing a port of entry during inoculation of foods while maintaining anaerobiosis. Following inoculation, the SS was covered by molten wax and aluminum foil. Anaerobic growth in the packs was demonstrated by gas formation by several species of clostridia. Staphylococci also grew anaerobically.

Control of Foaming during Microbiological Analysis of Foods and Recovery of Indicator Organisms

Persistent foam formation occurring during blending of jelly powder (JP), whole egg powder (WEP) and skim milk power (SMP) was demonstrated. Reduction of foaming was uniformly best achieved by using the Colworth Stomacher 400 (STOM) for mixing or blending under a vacuum (VAC). Two hundred, 1000 and 6000 ppm of Dow Corning Antifoam Agent (DAF) was necessary to reduce foaming of JP, SMP and WEP, respectively. Escherichia coli was recovered in similar numbers from JP, SMP and WEP by normal blending (N), STOM, VAC or by the application of 200 ppm of DAF. Significantly lower recovery of Staphylococcus aureus from JP resulted when N or VAC was employed and from SMP when STOM was used. Streptococcus faecalis showed significantly lower recoveries from JP and WEP when STOM or VAC and DAF at 200 ppm were used.