Outcomes for the first wave of hospitalised patients with COVID-19 in the South Australian context: a retrospective audit.

BACKGROUND: The first case of corona virus disease (COVID-19) was detected in South Australia on 1 February 2020. The Royal Adelaide Hospital (RAH) is the state's designated quarantine hospital. AIM: To determine the characteristics, outcomes and predictors of outcomes for hospitalised patients with coronavirus disease (COVID-19) within the RAH. METHODS: We performed a retrospective audit of 103 patients diagnosed with COVID-19 who were discharged from the RAH between 14 February and 21 May 2020. We collected demographic, clinical and laboratory data through an audit of electronic medical records. The main outcome measures were: (i) the need for oxygen supplementation; (ii) need for intensive care unit (ICU) care; and (iii) death in hospital. RESULTS: The median age of patients was 60 years (range 19-85). A total of 55 (53%) patients was male. All patients were independent at baseline; 37 (36%) patients suffered from hypertension. Cardiovascular disease, respiratory disease and diabetes were present in fewer than 19 (18%) patients. Obesity was present in 24 (23%) patients; 39 (38%) patients required supplemental oxygen, 18 (17%) required ICU care and 4 (4%) patients died. Older patients were significantly more at risk of oxygen requirement (median 68 vs 57.5 years, P < 0.01), ICU admission (median 66.5 vs 60 years, P = 0.04) and death (median 74.5 vs 60 years, P = 0.02). We did not find a statistically significant association between gender, body mass index and poor outcomes. Lactate dehydrogenase (LDH) was the only parameter at admission associated with oxygen requirement, ICU care and death. Peak LDH, aspartate aminotransferase, alanine aminotransferase, C-reactive protein and neutrophil lymphocyte ratio were significantly associated with oxygen requirement, ICU admission and death (P < 0.05 for all of the above laboratory markers). CONCLUSIONS: Although our sample size was small, we found that certain comorbidities and laboratory values were associated with poor outcomes. This occurred in a setting where care was not influenced by limited hospital and intensive care beds.

γH2AX is increased in peripheral blood lymphocytes of Alzheimer's disease patients in the South Australian Neurodegeneration, Nutrition and DNA Damage (SAND) study of aging.

An early cellular response to DNA double-strand breaks is the phosphorylation of histone H2AX to form γH2AX. Although increased levels of γH2AX have been reported in neuronal nuclei of Alzheimer's disease (AD) patients, γH2AX responses in the lymphocytes of individuals with mild cognitive impairment (MCI) and AD remain unexplored. In this study, the endogenous γH2AX level was measured, using laser scanning cytometry (LSC) and visual scoring, in lymphocyte nuclei from MCI (n = 18), or AD (n = 20) patients and healthy controls (n = 40). Levels were significantly elevated in nuclei of the AD group compared to the MCI and control groups, and there was a concomitant increase, with a significant trend, from the control group through MCI to the AD group. A significant negative correlation was seen between γH2AX and the mini mental state examination (MMSE) score, when the analysis included all subjects. Receiver Operation Characteristic curves were carried out for different γH2AX parameters; visually scored percent cells containing overlapping γH2AX foci displayed the best area under the curve value of 0.9081 with 85% sensitivity and 92% specificity for the identification of AD patients versus control. Plasma homocysteine, creatinine, and chitinase-3-like protein 1 (CHI3L1) were positively correlated with lymphocyte γH2AX signals, while glomerular filtration rate (GFR) was negatively correlated. Finally, there was a diminished γH2AX response to X-rays in lymphocytes of the MCI and AD groups compared to the control group. Our results indicate that lymphocyte γH2AX levels are a potential marker for identifying individuals at increased risk of developing AD. Prospective studies with normal healthy individuals are needed to test whether there is indeed a link between γH2AX levels and AD risk.

Guanine-quadruplexes are increased in mild cognitive impairment and correlate with cognitive function and chromosomal DNA damage.

Guanine-quadruplexes (G4) are highly stable DNA secondary structures known to mediate gene regulation and to trigger genomic instability events during replication. G4 are known to be associated with DNA damage and we propose that G4 are involved in the ageing disorder mild cognitive impairment (MCI). Lymphocytes were obtained from healthy controls and individuals with MCI. The intensity and frequency of G4 foci as well as γH2AX (a marker of DNA damage) intensity were measured by quantitative immunofluorescence and were correlated with cognitive function and cytokinesis-block micronucleus cytome markers of DNA damage. γH2AX intensity as well as G4 frequency and intensity were significantly elevated in MCI lymphocytes compared to controls. The combined biomarker panel was tested in a predictive statistical model, which improved the demarcation of MCI from controls with 80.3% accuracy. The results obtained from this pilot study showed for the first time that G4 levels are increased with cognitive impairment and thus, may be involved in the early development of Alzheimer's disease possibly via an association with chromosomal DNA damage and DNA double strand breaks.

Chromosomal DNA damage measured using the cytokinesis-block micronucleus cytome assay is significantly associated with cognitive impairment in South Australians.

Loss of genome integrity may be associated with increased risk for neurodegenerative disease. The aim of this study was to investigate whether mild cognitive impairment (MCI) or Alzheimer's disease (AD) individuals have increased DNA damage relative to age- and gender- matched controls using the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay. DNA damage was measured as micronuclei (MN), nucleoplasmic bridges (NPB), and nuclear buds (NBUD) in binucleated cells. The assay was performed on blood samples from 80 participants consisting of (i) MCI cases (N = 20) and age- and gender- matched controls (N = 20), and (ii) AD cases (N = 20) and age- and gender- matched controls (N = 20). There was a significant increase in MCI NBUD frequency (P = 0.006) relative to controls, which was also observed in male (P = 0.03) and female (P = 0.04) subgroups. For AD cases, there were no significant differences in assay biomarkers relative to controls. There was a significant negative correlation between Mini Mental State Examination (MMSE) and (i) MN in all controls, (R = -0.3, P = 0.04), and AD cases (R = -0.4, P = 0.03), (ii) NPB in all controls, (R = -0.4, P = 0.006) and AD cases (R = -0.5, P = 0.01), and (iii) NBUD in MCI cases (R = -0.5, P = 0.007) and AD cases (R = -0.7, P = 0.0002). The results suggest that an increase in lymphocyte CBMN-Cyt DNA damage biomarkers may be associated with cognitive decline.

Altered cytological parameters in buccal cells from individuals with mild cognitive impairment and Alzheimer's disease.

Previous studies have shown that mild cognitive impairment (MCI) may be reflective of the early stages of more pronounced neurodegenerative disorders such as Alzheimer's disease (AD). There is a need for a minimally invasive and inexpensive diagnostic to identify those who exhibit cellular pathology indicative of MCI and AD risk so that they can be prioritized for primary preventative measures. The hypothesis was that a minimally invasive approach using cytological markers in isolated buccal mucosa cells can be used to identify individuals of both MCI and AD. An automated buccal cell assay was developed using laser scanning cytometry (LSC) to measure buccal cell type ratios, nuclear DNA content and shape, and neutral lipid content of buccal cells from clinically diagnosed AD (n = 13) and MCI (n = 13) patients prior to treatment compared to age- and gender-matched controls (n = 26). DNA content was significantly higher in all cell types in both MCI (P < 0.01) and AD (P < 0.05) compared with controls mainly due to an increase in >2N nuclei. Abnormal nuclear shape (circularity) was significantly increased in transitional cells in MCI (P < 0.001) and AD (P < 0.01) when compared to controls. In contrast, neutral lipid content (as measured by Oil red O "ORO" staining) of buccal cells was significantly lower in the MCI group (P < 0.05) compared with the control group. The ratio of DNA content/ORO in buccal basal cells for both MCI and AD was significantly higher compared to the control group, with ratios for MCI being approximately 2.8-fold greater (P < 0.01) and AD approximately 2.3-fold greater (P < 0.05) than the control group. Furthermore, there was a strong negative correlation between buccal cell DNA content and ORO content in the AD group (r(2) = 0.75, P < 0.0001) but not in MCI or controls. The changes in the buccal cell cytome observed in this study could prove useful as potential biomarkers in identifying individuals with an increased risk of developing MCI and eventually AD.

Buccal micronucleus cytome biomarkers may be associated with Alzheimer's disease.

Alzheimer's disease (AD) is a progressive degenerative disorder of the brain and is the commonest form of dementia. A buccal cytome assay was used to measure ratios of buccal cell populations and micronuclei in clinically diagnosed Alzheimer's patients compared to age and gender-matched controls. Frequencies of basal cells (P < 0.0001), condensed chromatin cells (P < 0.0001) and karyorrhectic cells (P < 0.0001) were found to be significantly lower in Alzheimer's patients. These changes may reflect alterations in the cellular kinetics or structural profile of the buccal mucosa, and may be useful as potential biomarkers in identifying individuals with a high risk of developing AD. The odds ratio of being diagnosed with AD for those individuals with a basal cell plus karyorrhectic cell frequency <41 per 1000 cells is 140, with a specificity of 97% and sensitivity of 82%. These promising results need to be replicated in larger studies and in cohorts of other neurodegenerative disorders to determine specificity of changes to Alzheimer's patients.

Vasodepressor syncope and the diagnostic accuracy of the head-up tilt test with sublingual glyceryl trinitrate.

Thirteen syncopal subjects and thirteen asymptomatic controls were examined by head-up tilt (HUT) with and without sublingual GTN. Adding GTN to HUT improved the sensitivity of the test (8 % to 46%) but decreased specificity (100 % to 54 %).