Decreased white matter integrity in fronto-occipital fasciculus bundles: Relation to visual information processing in alcohol-dependent subjects

Chronic alcohol abuse is characterized by impaired cognitive abilities with a more severe deficit in visual than in verbal functions. Neuropathologically, it is associated with widespread brain structural compromise marked by gray matter shrinkage, ventricular enlargement, and white matter degradation. The present study sought to increase current understanding of the impairment of visual processing abilities in alcohol-dependent subjects, and its correlation with white matter microstructural alterations, using diffusion tensor imaging (DTI). To that end, a DTI study was carried out on 35 alcohol-dependent subjects and 30 healthy male control subjects. Neuropsychological tests were assessed for visual processing skills and deficits were reported as raw dysfunction scores (rDyS). Reduced FA (fractional anisotropy) and increased MD (mean diffusivity) were observed bilaterally in inferior and superior fronto-occipital fasciculus (FOF) fiber bundles. A significant inverse correlation in rDyS and FA values was observed in these fiber tracts whereas a positive correlation of these scores was found with the MD values. Our results suggest that FOF fiber bundles linking the frontal lobe to occipital lobe might be related to visual processing skills. This is the first report of an alteration of the white matter microstructure of FOF fiber bundles that might have functional consequences for visual processing in alcohol-dependent subjects who exhibit no neurological complications.     

Management of dental trauma in a child with Xeroderma Pigmentosa

Xeroderma Pigmentosa is a rare dermatological autosomal recessive disorder that manifests itself early in life as severe sunburn usually after a short exposure to sunlight. The prime characteristic features include photosensitivity, hyperpigmentation and ichthyosis in sun exposed areas, and an increase in the risk of basocellular and squamous cell carcinomas and melanomas of the skin and eyes. The case report highlights the preventive treatment options along with all necessary precautions that should be taken to protect the patient from any iatrogenic inadvertent exposures that may be deleterious to his present state. The purpose of the report is also to discuss the important role of dental professionals when dealing with debilitating medical conditions.     

Quantitative computed tomography assessment of transfusional iron overload

Quantitative computed tomography (QCT) has been proposed for iron quantification for more than 30 years, however there has been little clinical validation. We compared liver attenuation by QCT with magnetic resonance imaging (MRI)-derived estimates of liver iron concentration (LIC) in 37 patients with transfusional siderosis. MRI and QCT measurements were performed as clinically indicated monitoring of LIC and vertebral bone-density respectively, over a 6-year period. Mean time difference between QCT and MRI studies was 14 d, with 25 studies performed on the same day. For liver attenuation outside the normal range, attenuation values rose linearly with LIC (r(2) = 0·94). However, intersubject variability in intrinsic liver attenuation prevented quantitation of LIC <8 mg/g dry weight of liver, and was the dominant source of measurement uncertainty. Calculated QCT and MRI accuracies were equivalent for LIC values approaching 22 mg/g dry weight, with QCT having superior performance at higher LIC's. Although not suitable for monitoring patients with good iron control, QCT may nonetheless represent a viable technique for liver iron quantitation in patients with moderate to severe iron in regions where MRI resources are limited because of its low cost, availability, and high throughput.     

CD137 ligand signaling enhances myelopoiesis during infections

CD137 and its ligand are expressed in the BM, and conflicting data exist on the regulation of myelopoiesis by the CD137 receptor–ligand system. CD137^?/? mice have increased numbers of myeloid cells in the BM, indicating an inhibitory influence of CD137 on myelopoiesis. However, CD137 also induces proliferation of hematopoietic progenitor cells and their myeloid differentiation, arguing for an enhancing effect. Here we hypothesized that this latter case represents the situation during infections since expression of CD137 is activation dependent and strongly enhanced during inflammation. Indeed, infections with Influenza, Bordetella pertussis, Mycobacterium bovis, Bacille Calmette‐Guérin or Escherichia coli or i.p. injection of LPS led to increased numbers of CD137‐expressing cells, especially of CD4⁺ T cells in the BM of mice. Coculture experiments confirmed that CD137 expression enables CD4⁺ T cells to induce proliferation and myeloid differentiation of BM and hematopoietic progenitor cells. CD137 also enhances myelopoiesis in vivo since the infection‐induced increase in myeloid cell proliferation and total myeloid cell numbers in the BM were significantly lower in CD137^?/? mice. This study reconciles earlier conflicting data by demonstrating that while CD137–CD137L interactions inhibit myelopoiesis during steady‐state conditions they increase myelopoiesis during infection.     

A study on the morbid histopathological changes in COVID-19 patients with or without comorbidities using minimally invasive tissue sampling

COVID-19 causes morbid pathological changes in different organs including lungs, kidneys, liver, and so on, especially in those who succumb. Though clinical outcomes in those with comorbidities are known to be different from those without—not much is known about the differences at the histopathological level. To compare the morbid histopathological changes in COVID-19 patients between those who were immunocompromised (Gr 1), had a malignancy (Gr 2), or had cardiometabolic conditions (hypertension, diabetes, or coronary artery disease) (Gr 3), postmortem tissue sampling (minimally invasive tissue sampling [MITS]) was done from the lungs, kidney, heart, and liver using a biopsy gun within 2 hours of death. Routine (hematoxylin and eosin) and special staining (acid fast bacilli, silver methanamine, periodic acid schiff) was done besides immunohistochemistry. A total of 100 patients underwent MITS and data of 92 patients were included (immunocompromised: 27, malignancy: 18, cardiometabolic conditions: 71). In lung histopathology, capillary congestion was more in those with malignancy, while others like diffuse alveolar damage, microthrombi, pneumocyte hyperplasia, and so on, were equally distributed. In liver histopathology, architectural distortion was significantly different in immunocompromised; while steatosis, portal inflammation, Kupffer cell hypertrophy, and confluent necrosis were equally distributed. There was a trend towards higher acute tubular injury in those with cardiometabolic conditions as compared to the other groups. No significant histopathological difference in the heart was discerned. Certain histopathological features were markedly different in different groups (Gr 1, 2, and 3) of COVID-19 patients with fatal outcomes.