Multifactorial White Matter Damage in the Acute Phase and Pre-Existing Conditions May Drive Cognitive Dysfunction after SARS-CoV-2 Infection: Neuropathology-Based Evidence

BACKGROUND

There is an urgent need to better understand the mechanisms underlying acute and long-term neurological symptoms after COVID-19. Neuropathological studies can contribute to a better understanding of some of these mechanisms.

METHODS

We conducted a detailed postmortem neuropathological analysis of 32 patients who died due to COVID-19 during 2020 and 2021 in Austria.

RESULTS

All cases showed diffuse white matter damage with a diffuse microglial activation of a variable severity, including one case of hemorrhagic leukoencephalopathy. Some cases revealed mild inflammatory changes, including olfactory neuritis (25%), nodular brainstem encephalitis (31%), and cranial nerve neuritis (6%), which were similar to those observed in non-COVID-19 severely ill patients. One previously immunosuppressed patient developed acute herpes simplex encephalitis. Acute vascular pathologies (acute infarcts 22%, vascular thrombosis 12%, diffuse hypoxic-ischemic brain damage 40%) and pre-existing small vessel diseases (34%) were frequent findings. Moreover, silent neurodegenerative pathologies in elderly persons were common (AD neuropathologic changes 32%, age-related neuronal and glial tau pathologies 22%, Lewy bodies 9%, argyrophilic grain disease 12.5%, TDP43 pathology 6%).

CONCLUSIONS

Our results support some previous neuropathological findings of apparently multifactorial and most likely indirect brain damage in the context of SARS-CoV-2 infection rather than virus-specific damage, and they are in line with the recent experimental data on SARS-CoV-2-related diffuse white matter damage, microglial activation, and cytokine release.

Patents as a Competitive Advantage? Analysis of the German Watch Manufacturer Junghans

This paper investigates the relevance of patents as a competitive advantage with regard to the luxury industry. Within the framework of an explorative research design, more than two thousand patents were analyzed, using the international patent classification (IPC) to cluster those patents. The analysis shows that the sole ownership of patents as a resource is not sufficient to achieve business success. In addition, the findings suggest a two-sided relevance of patents within the luxury goods industry as two main groups can be identified: First, traditional manufacturers focusing more on craftmanship, secrecy, and tradition than on novelties and patents. Second, large business groups and high technology businesses dominating the IPC group G04 and emphasizing on the latest technology as well as on patents. Furthermore, the internationalization is also reflected in the patent applications: European patents within category G04 have gained in importance over the last 20 years, while national patents have declined.

Manganese-mediated MRI signals correlate with functional β-cell mass during diabetes progression

Diabetes diagnostic therapy and research would strongly benefit from noninvasive accurate imaging of the functional β-cells in the pancreas. Here, we developed an analysis of functional β-cell mass (BCM) by measuring manganese (Mn(2+)) uptake kinetics into glucose-stimulated β-cells by T1-weighted in vivo Mn(2+)-mediated MRI (MnMRI) in C57Bl/6J mice. Weekly MRI analysis during the diabetes progression in mice fed a high-fat/high-sucrose diet (HFD) showed increased Mn(2+)-signals in the pancreas of the HFD-fed mice during the compensation phase, when glucose tolerance and glucose-stimulated insulin secretion (GSIS) were improved and BCM was increased compared with normal diet-fed mice. The increased signal was only transient; from the 4th week on, MRI signals decreased significantly in the HFD group, and the reduced MRI signal in HFD mice persisted over the whole 12-week experimental period, which again correlated with both impaired glucose tolerance and GSIS, although BCM remained unchanged. Rapid and significantly decreased MRI signals were confirmed in diabetic mice after streptozotocin (STZ) injection. No long-term effects of Mn(2+) on glucose tolerance were observed. Our optimized MnMRI protocol fulfills the requirements of noninvasive MRI analysis and detects already small changes in the functional BCM.

The adipocytokine Nampt and its product NMN have no effect on beta-cell survival but potentiate glucose stimulated insulin secretion

AIMS/HYPOTHESIS

Obesity is associated with a dysregulation of beta-cell and adipocyte function. The molecular interactions between adipose tissue and beta-cells are not yet fully elucidated. We investigated, whether or not the adipocytokine Nicotinamide phosphoribosyltransferase (Nampt) and its enzymatic product Nicotinamide mononucleotide (NMN), which has been associated with obesity and type 2 diabetes mellitus (T2DM) directly influence beta-cell survival and function.

METHODS

The effect of Nampt and NMN on viability of INS-1E cells was assessed by WST-1 assay. Apoptosis was measured by Annexin V/PI and TUNEL assay. Activation of apoptosis signaling pathways was evaluated. Adenylate kinase release was determined to assess cytotoxicity. Chronic and acute effects of the adipocytokine Nampt and its enzymatic product NMN on insulin secretion were assessed by glucose stimulated insulin secretion in human islets.

RESULTS

While stimulation of beta-cells with the cytokines IL-1β, TNFα and IFN-γ or palmitate significantly decreased viability, Nampt and NMN showed no direct effect on viability in INS-1E cells or in human islets, neither alone nor in the presence of pro-diabetic conditions (elevated glucose concentrations and palmitate or cytokines). At chronic conditions over 3 days of culture, Nampt and its product NMN had no effects on insulin secretion. In contrast, both Nampt and NMN potentiated glucose stimulated insulin secretion acutely during 1 h incubation of human islets.

CONCLUSION/INTERPRETATION

Nampt and NMN neither influenced beta-cell viability nor apoptosis but acutely potentiated glucose stimulated insulin secretion.

[The guardianship law and physician's responsibility]

From 1992 a new law regulating the taking care of another person's legal and personal affairs and nursing problems has become effective. The aim of this law is to establish an individual and respectful relationship between the patient in care and the appointed person. The appointed person has to emphathize with the patient in his care to a degree where he is able to make decisions that reflect the individual lifestyle and life history of the patient in care. Fundamentally, it is the patient's right to make his own decisions about medical treatment according to tis own experience, personal values and emotions. If the patient is unable to make his own decisions for health reasons a caretaking person is appointed by decree. In respecting the patient's will stringent standards are necessary. The new law offers possibilities of freedom of decision and self-responsibility that should never be restricted again.

[Social workers in the commitment procedure]

Regular inclusion of a social worker alongside the expertising physician whenever a judge has to decide on committing a person to a psychiatric hospital, is known in German legal practice as "Stuttgart model". Our experiences with this procedure are discussed on an interdisciplinary level. In our opinion this model agrees with the spirit of the new German law governing guardianship and care.

Assessment of peripheral vascular disease in patients with diabetes. Two case studies

This report proposes that perfusion scanning in combination with arteriography be included in the diagnostic work-up of the diabetic patient who, because of peripheral vascular complications, is a candidate for surgery. Two cases are reported which illustrate the extremes of the findings: abnormal arteriogram-normal scan indicating large-vessel disease without significant small-vessel involvement. It is suggested that these patients are candidates for vascular reconstruction. The other extreme is the normal arteriogram-abnormal scan indicating small-vessels disease without significant large-vessel involvement. It is apparent that these patients are not candidates for vascular reconstruction.