Quantitative multiplexed strategies for human Lyme disease serological testing

Lyme disease, which is primarily caused by infection with the bacterium Borrelia burgdorferi in the United States or other Borrelia species internationally, presents an ongoing challenge for diagnostics. Serological testing is the primary means of diagnosis but testing approaches differ widely, with varying degrees of sensitivity and specificity. Moreover, there is currently no reliable test to determine disease resolution following treatment. A distinct challenge in Lyme disease diagnostics is the variable patterns of human immune response to a plurality of antigens presented by Borrelia spp. during the infection. Thus, multiplexed testing approaches that capture these patterns and detect serological response against multiple antigens may be the key to prompt, accurate Lyme disease diagnosis. In this review, current state-of-the-art multiplexed diagnostic approaches are presented and compared with respect to their diagnostic accuracy and their potential for monitoring response to treatment.

Multiplexed detection and quantification of human antibody response to COVID-19 infection using a plasmon enhanced biosensor platform

The 2019 SARS CoV-2 (COVID-19) pandemic has illustrated the need for rapid and accurate diagnostic tests. In this work, a multiplexed grating-coupled fluorescent plasmonics (GC-FP) biosensor platform was used to rapidly and accurately measure antibodies against COVID-19 in human blood serum and dried blood spot samples. The GC-FP platform measures antibody-antigen binding interactions for multiple targets in a single sample, and has 100% selectivity and sensitivity (n = 23) when measuring serum IgG levels against three COVID-19 antigens (spike S1, spike S1S2, and the nucleocapsid protein). The GC-FP platform yielded a quantitative, linear response for serum samples diluted to as low as 1:1600 dilution. Test results were highly correlated with two commercial COVID-19 antibody tests, including an enzyme linked immunosorbent assay (ELISA) and a Luminex-based microsphere immunoassay. To demonstrate test efficacy with other sample matrices, dried blood spot samples (n = 63) were obtained and evaluated with GC-FP, yielding 100% selectivity and 86.7% sensitivity for diagnosing prior COVID-19 infection. The test was also evaluated for detection of multiple immunoglobulin isotypes, with successful detection of IgM, IgG and IgA antibody-antigen interactions. Last, a machine learning approach was developed to accurately score patient samples for prior COVID-19 infection, using antibody binding data for all three COVID-19 antigens used in the test.

Evaluation of DNA methylation at imprinted DMRs in the spermatozoa of oligozoospermic men in association with MTHFR C677T genotype

Altered DNA methylation has been previously identified in the spermatozoa of infertile men; however, the origins of these errors are poorly understood. DNA methylation is an epigenetic modification which is thought to play a fundamental role in male germline development. DNA methylation reactions rely on the cellular availability of methyl donors, which are primarily products of folate metabolism, where a key enzyme is methylenetetrahydrofolate reductase (MTHFR). The MTHFR C677T single nucleotide polymorphism (SNP) reduces enzyme activity and may potentially alter DNA methylation processes during germline development. The objective of this study was to determine whether altered DNA methylation in spermatozoa is associated with the MTHFR C677T SNP. DNA methylation was evaluated at the H19, IG-GTL2, and MEST imprinted differentially methylated regions in the spermatozoa of 53 men - 44 oligozoospermic men and nine fertile men with normal sperm parameters via bisulfite sequencing of sperm clones. The 44 infertile men were stratified by severity of oligozoospermia - three normal (>15 million spermatozoa/mL), eight moderate (5-15 million spermatozoa/mL), 23 severe (1-5 million spermatozoa/mL), and 10 very severe (<1 million spermatozoa/mL). MTHFR C677T SNP genotyping was conducted in a subset of 44 peripheral blood samples via restriction fragment length polymorphism. A total of three men - severe oligozoospermic and CT genotype - were found to be altered, which is defined as having ≥50% of their clones altered, where an altered clone was in turn defined as ≥50% of CpGs with incorrect DNA methylation patterns. The incidence of three altered men within the CT subgroup, however, was not significantly higher than the incidence in the CC subgroup. Taken together, altered DNA methylation in spermatozoa was not significantly associated with the MTHFR C677T SNP; however, there was a trend for higher incidence of alterations among severe oligozoospermic infertile men with CT genotypes.

Large duplication in MTM1 associated with myotubular myopathy

Myotubular myopathy is a subtype of centronuclear myopathy with X-linked inheritance and distinctive clinical and pathologic features. Most boys with myotubular myopathy have MTM1 mutations. In remaining individuals, it is not clear if disease is due to an undetected alteration in MTM1 or mutation of another gene. We describe a boy with myotubular myopathy but without mutation in MTM1 by conventional sequencing. Array-CGH analysis of MTM1 uncovered a large MTM1 duplication. This finding suggests that at least some unresolved cases of myotubular myopathy are due to duplications in MTM1, and that array-CGH should be considered when MTM1 sequencing is unrevealing.

Metal-induced assembly of a semiconductor island lattice: Ge truncated pyramids on Au-patterned Si

We report the two-dimensional alignment of semiconductor islands using rudimentary metal patterning to control nucleation and growth. In the Ge on Si system, a square array of submicron Au dots on the Si (001) surface induces the assembly of deposited Ge adatoms into an extensive island lattice. Remarkably, these highly ordered Ge islands form between the patterned Au dots and are characterized by a unique truncated pyramidal shape. A model based on patterned diffusion barriers explains the observed ordering and establishes general criteria for the broader applicability of such a directed assembly process to quantum dot ordering.

Atherosclerosis risk factors in patients in acute cerebral stroke in relation to sex and age

The study was performed in 44 patients (28 female and 16 male, age range 46-85 years) in an acute period of cerebral stroke. The concentrations of serum glycohemoglobin, fructosamine, lipoprotein (a) (Lp(a)), triglycerides (TG), total cholesterol (TCh), as well as cholesterol of HDL and LDL fractions (HDL-Ch, LDL-Ch) were measured and atherogenic factors: TCh/HDL-Ch, LDL-Ch/HDL-Ch were calculated. We found, that the highest values of these factors were observed in women aged 60-70 years and in men over 80 years.

Hyperglycemic and lipid parameters in diabetic and nondiabetic patients after acute cerebral stroke

In 44 patients in acute period of cerebral stroke (35 with a normal glucose tolerance and 9 with non-insulin-dependent diabetes), the concentration of: glycohemoglobin, fructosamine, lipoprotein (a), triglycerides (TG), total cholesterol (TCh), as well as, HDL-cholesterol (HDL-Ch) and LDL-cholesterol (LDL-Ch) were measured and atherogenic factors: TCh/HDL-Ch, LDL-Ch/HDL-Ch, TG/HDL-Ch were calculated. Diabetic patients in acute period of cerebral stroke showed not statistically significant increase of lipids, lipoproteins, glycohemoglobin and fructosamine concentrations, as compared with nondiabetic patients.

[Lipid metabolism parameters in patients with multi-infarct dementia and Alzheimer's type dementia]

The concentrations were determined of triglycerides (TG), total cholesterol (Ch), high density fraction of (HDL-Ch), low density fraction of cholesterol (LDL-Ch), apolipoprotein B (apo-B) in patients with dementia of Alzheimer type (DAT, 14 patients) and multi-infarct dementia (MID, 63 patients). No significant differences in the estimated lipid parameters in both groups were found, except the calculated value of atherogenic index (Ch/HDL-Ch), which was significantly higher in patients with MID. Our results suggest that this parameter is a much more sensitive atherogenic indicator in blood-vessels than other tested lipid parameters. This finding may influence the therapeutic approach to patients with dementia.

The painless intussusception

There were 422 cases of intussusception at the Hospital for Sick Children, Toronto, over a 12-yr period between 1959 and 1970. The histories of all patients who had no pain recorded were evaluated and the duration of signs and symptoms and the treatment required assessed. When compared with those who had pain, it was noted that the children with painless intussusception presented later, hydrostatic reduction was less likely to be effective, and operative reduction and resection was required more often.