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Background: Vertebral compression fractures (VCF) lead to both considerable morbidity and increased mortality. Kyphoplasty, a minimally invasive surgery, treats VCFs providing significant pain relief, preserving vertebral height, and reducing spinal deformity. Methods: A retrospective cohort study at Hamilton Health Sciences (HHS) was conducted on elderly patients (60 years or older) who underwent kyphoplasty at between 2012 and 2022. The patients had prior hospital admissions under non-spine-related specialties at HHS within two years before their surgery. Primary outcomes were the progression of vertebral height loss and focal kyphotic deformity. Results: The study included 119 patients (52.1% female, mean age 70.71 years). A significant increase in vertebral height loss was observed from diagnosis to pre-kyphoplasty (0.32% change, p < 0.0001) and from diagnosis to post-kyphoplasty (0.24% change, p = 0.015). However, there were no significant correlations between delay times and changes in vertebral height or focal kyphotic deformity. Conclusions: Delays in neurosurgical consultation and kyphoplasty did not significantly affect radiographic outcomes in elderly patients with VCF despite the progression of vertebral height loss. This suggests that while timely patient care is essential, delayed treatment may not adversely affect key radiographic metrics in elderly VCF patients.

α-2,3-Sialyltransferase (Lst) is expressed on the outer membrane of Neisseria gonorrhoeae and Neisseria meningitidis and sialylates surface lipooligosaccharide (LOS), facilitating resistance to complement-mediated killing. The enzyme is constitutively expressed from a single gene (lst) and does not undergo antigenic or phase variation. We observed that Triton X-100 extracts of N. gonorrhoeae strain F62 contain about fivefold more sialyltransferase (Stase) activity than extracts of N. meningitidis strain MC58 Formula 3 a serogroup B acapsulate mutant. We confirmed and expanded upon this observation by showing that extracts of 16 random N. gonorrhoeae isolates contain various amounts of Stase activity, but, on average, 2.2-fold-more Stase activity than extracts of 16 N. meningitidis clinical isolates, representing several serogroups and nongroupable strains. Northern and real-time reverse transcription-PCR analysis of lst transcript levels in N. gonorrhoeae and N. meningitidis revealed that N. gonorrhoeae strains express more lst transcript than N. meningitidis strains. Although transcript levels correlate with average Stase activity observed in the two species, there was not a direct correlation between lst transcript levels and Stase activity among individual isolates of each species. Comparison of lst upstream (5'lst) regions of N. gonorrhoeae and N. meningitidis revealed striking sequence differences characteristic of the two pathogens. N. gonorrhoeae 5'lst regions possess 30-bp and 13-bp elements present as single elements or as tandem repeats that exist only as single elements in the 5'lst regions of N. meningitidis isolates. In addition, the 5'lst regions of N. meningitidis strains have 105-bp transposon-like Correia elements which are absent in N. gonorrhoeae. Chromosomal N. gonorrhoeae 5'lst::lacZ translational fusions expressed 4.75 ± 0.09-fold (n = 4) higher {szligbeta}-galactosidase ({szligbeta}-gal) activity than N. meningitidis 5'lst::lacZ fusions in a host-independent manner, indicating differential expression is governed at least in part by sequence variations in the 5'lst regions. Reporter fusion assays and promoter-mapping analysis revealed that N. gonorrhoeae and N. meningitidis use different promoters with different strengths to transcribe lst. In N. gonorrhoeae, a strong sigma 70 promoter 80 bp upstream of the translational start site is used to transcribe lst, whereas this promoter is inactive in N. meningitidis. In N. meningitidis, a weak sigma 70 promoter at the 3' terminus of a 105-bp Correia repeat-enclosed element 99 bp upstream of the translational start site is used to transcribe lst. We conclude that differential Stase expression between N. gonorrhoeae and N. meningitidis is due at least in part to differential lst gene transcription.

ABSTRACTα-2,3-Sialyltransferase (Lst) is expressed on the outer membrane of Neisseria gonorrhoeaeand Neisseria meningitidisand sialylates surface lipooligosaccharide (LOS), facilitating resistance to complement-mediated killing. The enzyme is constitutively expressed from a single gene (lst) and does not undergo antigenic or phase variation. We observed that Triton X-100 extracts of N. gonorrhoeaestrain F62 contain about fivefold more sialyltransferase (Stase) activity than extracts of N. meningitidisstrain MC58 ⊄3 a serogroup B acapsulate mutant. We confirmed and expanded upon this observation by showing that extracts of 16 random N. gonorrhoeaeisolates contain various amounts of Stase activity, but, on average, 2.2-fold-more Stase activity than extracts of 16 N. meningitidisclinical isolates, representing several serogroups and nongroupable strains. Northern and real-time reverse transcription-PCR analysis of lsttranscript levels in N. gonorrhoeaeand N. meningitidisrevealed that N. gonorrhoeaestrains express more lsttranscript than N. meningitidisstrains. Although transcript levels correlate with average Stase activity observed in the two species, there was not a direct correlation between lsttranscript levels and Stase activity among individual isolates of each species. Comparison of lstupstream (5′lst) regions of N. gonorrhoeaeand N. meningitidisrevealed striking sequence differences characteristic of the two pathogens. N. gonorrhoeae5′lstregions possess 30-bp and 13-bp elements present as single elements or as tandem repeats that exist only as single elements in the 5′lstregions of N. meningitidisisolates. In addition, the 5′lstregions of N. meningitidisstrains have 105-bp transposon-like Correia elements which are absent in N. gonorrhoeae. Chromosomal N. gonorrhoeae5′lst::lacZtranslational fusions expressed 4.75 ± 0.09-fold (n= 4) higher β-galactosidase (β-gal) activity than N. meningitidis5′lst::lacZfusions in a host-independent manner, indicating differential expression is governed at least in part by sequence variations in the 5′lstregions. Reporter fusion assays and promoter-mapping analysis revealed that N. gonorrhoeaeand N. meningitidisuse different promoters with different strengths to transcribe lst. In N. gonorrhoeae, a strong sigma 70 promoter 80 bp upstream of the translational start site is used to transcribe lst, whereas this promoter is inactive in N. meningitidis. In N. meningitidis, a weak sigma 70 promoter at the 3′ terminus of a 105-bp Correia repeat-enclosed element 99 bp upstream of the translational start site is used to transcribe lst. We conclude that differential Stase expression between N. gonorrhoeaeand N. meningitidisis due at least in part to differential lstgene transcription.

Graft vessel disease (GVD) is a major cause of graft loss after the first year following transplantation. GVD is a complex, multifunctional process that involves immunological as well as non-immunological events such as ischaemia/reperfusion injury. An important target cell to interfere with the development of GVD is the smooth muscle cell (SMC). Somatostatin (SRIF) analogues have been shown previously to inhibit the proliferation of SMC in vitro and in vivo. We provide evidence that Sandostatin, an octapeptide SRIF analogue that is known to have anti-proliferative properties on SMC proliferation, inhibits vascular remodelling in a rat angioplasty model. Furthermore, in two allotransplantation models, Sandostatin effectively interferes with the development of signs of chronic rejection/GVD. The role of the different SRIF receptor subtypes in chronic graft rejection is currently under investigation.

Magnetite is a common product of bacterial iron reduction and may serve as a potential physical indicator of biological activity in geological settings. Here we report the formation of single-domain magnetite under laboratory conditions by a thermophilic fermentative bacterial strain TOR-39 that was isolated from the deep subsurface. Time-course analyses were performed at 65 °C to study the effect of bacterial activity on solution chemistry and magnetite formation during the growth of TOR-39. Run products were examined by transmission electron microscopy. Magnetite particles formed exclusively outside of bacterial cells and exhibited octahedral shapes having relatively equal length and width (< 15% difference). Tiny magnetite particles (< 12 nm) nucleated between 10 and 11 h of incubation and increased to average lengths of 55.4 ± 26.8 nm after 24 h of incubation. Between 24 h and 22 d of incubation, magnetite particles maintained average lengths of 56.2 ± 24.8 nm. Based on size constraints, greater than 85% of the particles observed fell within the magnetic single domain. Little to no magnetite was detected in abiotic controls at 65 or 95 °C, or in TOR-39 cultures whose activity was suppressed. Unlike mesophilic iron-reducing bacteria (e.g., GS-15), TOR-39 produced crystals having shapes and sizes similar to some particles produced intracellularly by magnetotactic bacteria. Thus the single- domain magnetite produced by thermophiles such as TOR-39 may represent a heretofore unrecognized biological contribution to natural remanent magnetization in sedimentary basins and other geothermal environments.

The redox reactions of Fe(CN)64−/Fe(CN)63−, Fe2+/Fe3+, and Ce3+/Ce4+systems on α-Fe2O3electrodes containing different amounts of titanium were studied. The anodic current showed a tendency to be saturated in the Fe(CN)64−/Fe(CN)63−and Fe2+/Fe3+systems. The forward direction of the current flow in these systems was the reverse of the case with the lithiated NiO electrode. On the other hand, the cathodic current flow was negligible and the redox potential was not observed for the Ce3+/Ce4+system. It was concluded that the reaction proceeds through electron transfer and that I–Vcurves are determined by the influence of the potential barrier formed on the electrode surface over which an electron transfers from the electrode into the electrolyte or in the reverse direction.