The human carotid atherosclerotic plaque: an observational review of histological scoring systems.

OBJECTIVE: The atherosclerotic plaque is a complex dynamic pathological lesion of the arterial wall, characterized by multiple elementary lesions of different diagnostic and prognostic significance. Fibrous cap thickness, lipid necrotic core dimension, inflammation, intra-plaque hemorrhage (IPH), plaque neovascularization and endothelial dysfunction (erosions) are generally considered the most relevant morphological details of plaque morphology. In this review, the most relevant features able to discriminate between stable and vulnerable plaques at histological level are discussed. SUBJECTS AND METHODS: Retrospectively, we have evaluated the laboratory results from one hundred old histological samples from patients treated with carotid endarterectomy. These results were analyzed to assess elementary lesions that characterize stable and unstable plaques. RESULTS: A thin fibrous cap (<65 micron), loss of smooth muscle cells, collagen depletion, a large lipid-rich necrotic core, infiltrating macrophages, IPH and intra-plaque vascularization are identified as the most important risk factors associated with plaque rupture. CONCLUSIONS: Immunohistochemistry for smooth muscle actin (smooth muscle cell marker) and for CD68 (marker of monocytes/macrophages) and glycophorin (marker of red blood cells) are suggested as useful tools for an in deep characterization of any carotid plaque and for distinguishing plaque phenotypes at histology. Since patients with a carotid vulnerable plaque are at higher risk of developing vulnerable plaques in other arteries as well, the definition of the vulnerability index is underlined, in order to stratify patients at higher risk for undergoing cardiovascular events.

Expression of L1 Cell Adhesion Molecule (L1CAM) in extracellular vesicles in the human spinal cord during development.

OBJECTIVE: L1  cell adhesion molecule (L1CAM) is a glycoprotein characterized by three components: an extracellular region, a transmembrane segment, and a cytoplasmic tail. L1CAM is expressed in multiple human cells, including neurons. The neural cell adhesion molecule L1 has been implicated in a variety of neurologic processes, including neuritogenesis and cerebellar cell migration. The presence of L1CAM on the surface of nerve cells allows the adhesion of neurons among them. Furthermore, when it is bound to itself or to other proteins, L1-CAM induces signals inside the cell. The aim of this work was to study L1CAM expression in the human spinal cord during development, at different gestational ages, through immunohistochemistry. MATERIALS AND METHODS: Immunohistochemical analysis for L1CAM was performed in five human spinal cord samples, including three embryos and two fetuses of different gestational ages, ranging from 8 to 12 weeks. RESULTS: L1CAM expression was detected in all 5 spinal cords examined in this study. The adhesion molecule was found in the vast majority of cells. The highest levels of immunoreactivity for L1CAM were detected at the periphery of the developing organs, in the spinal cord zones occupied by sensory and motor fibers. In the alar and basal columns, immunoreactivity for L1CAM was characterized by a reticular pattern, being mainly expressed in axons. Strong reactivity of L1CAM was also found in extracellular vesicles. This extracellular localization might indicate the ability of L1CAM to mediate the transduction of extracellular signals that support axon outgrowth. CONCLUSIONS: The high reactivity of L1cam in the axons of developing neurons in the fetal spinal cord confirms previous studies on the ability of L1CAM to promote axon sprouting and branching in the developing nervous system. In this work, a new actor is reported to have a role in the complex field of human spinal cord development: L1CAM, whose expression is highly found in the developing neuronal and glial precursors.

The Role of Magnesium in Pregnancy and in Fetal Programming of Adult Diseases.

Magnesium is an essential trace metal and a necessary factor for multiple biochemical functions in humans. Its role in biology is fundamental in over 600 enzymatic reactions implicated in protein synthesis, mitochondrial functions, neuromuscular activity, bone formation, and immune system competence. Magnesium status is relevant in fetal development during gestation and in the newborn growth during the perinatal period. Moreover, magnesium is able to influence fetal programming and disease presentation in childhood or adulthood. The aim of this review is to focus on this metal homeostasis, analyzing its normal values, the causes of hypomagnesemia, the interaction with drugs and other conditions, and the diseases associated with magnesium value alteration during pregnancy, in order to study its role in fetal programming of adult diseases. The data here reported clearly indicated the existence of a connection between magnesium status and human pathology starting from intrauterine life and extending into childhood and adulthood.

Fetal programming of atherosclerosis: may the barker hypothesis explain the susceptibility of a subset of patients to develop stroke or cardiac infarct?

The risk stratification of young adults between subjects who will develop a mild form of atherosclerosis and subjects who will undergo a severe disease remains inaccurate. In the eighties of the previous century, David JP Barker has demonstrated the relationship between fetal conditions and occurrence of pathologies in adulthood. In this paper, the multiple evidence that might explain the increased susceptibility to severe forms of atherosclerosis, including stroke and cardiac infarct, in subjects who underwent intrauterine growth restriction (IUGR) will be analyzed. Specifically, we will review those inter-connected data indicating an association between a low weight at birth and an adult phenotype which might favor a severe outcome of atherosclerosis. Young and adult subjects born too small (IUGR) or too early (pre-terms) might represent a subgroup of "at risk subjects", more susceptible toward severe forms of atherosclerosis. Given that low birth weight (LBW) may be considered a surrogate of IUGR, this phenotypic feature could be considered among those indispensable clinical data collected in every patient presenting with atherosclerosis, irrespectively of age. According to the hypothesis that structural arterial changes might represent the link between LBW and susceptibility to atherosclerosis later in life, we suggest that the prevention of atherosclerosis should begin at birth. Regenerative and physiological substances such as thymosin Beta-4 could be challenged for a new "arterial regenerative medicine" in the perinatal period. The goal of this new approach should be the reinforcement of the structure of the arterial wall, allowing LBW newborns to avoid the most severe complications of atherosclerosis later in life: a dream that our research could contribute to bringing to life.

Vaccine-induced severe thrombotic thrombocytopenia following COVID-19 vaccination: a report of an autoptic case and review of the literature.

OBJECTIVE: Vaccine-induced immune thrombocytopenia (VITT) is a new syndrome occurring primarily in healthy young adults, with a female predominance, after receiving the first dose of ChAdOx1 nCoV-19 vaccine. We describe VITT syndrome characterized by severe thrombosis and thrombocytopenia found in our patient, with fatal outcome. CASE REPORT: A 58-year-old man, after 13 days from the first administration of ChAdOx1 nCoV-19 vaccine (AstraZeneca), presented with abdominal pain, diarrhea and vomitus. Laboratory tests revealed a severe thrombocytopenia, low fibrinogen serum levels and marked increase of D-dimer serum levels. The patient quickly developed a multiple organ failure, till death, three days after the hospital admission. RESULTS: At histology, in the lungs, interalveolar septa appeared thickened with microthrombi in the capillaries and veins. Interalveolar septa appeared thickened and showed vascular proliferation. Thrombi were detected in the capillaries of glomerular tufts. In the hearth, thrombi were observed in veins and capillaries. In the liver, voluminous fibrin thrombi were diffusely observed in the branches of the portal vein. Microthrombi were also found in the vasa vasorum of the wall of abdominal aorta. In the brain, microthrombi were observed in the capillaries of the choroid plexuses. Diffuse hemorrhagic necrosis was observed in the intestinal wall with marked congestion of the venous vessels. CONCLUSIONS: In our patient, the majority of data necessary for a VITT final diagnosis were present: thrombocytopenia and thrombosis in pulmonary, portal, hepatic, renal and mesenteric veins, associated with a marked increase of D-dimer serum levels. The finding of cerebral thrombosis in choroid plexuses, is a new finding in VITT. These features are suggestive for a very aggressive form of VITT.

Trace elements and the carotid plaque: the GOOD (Mg, Zn, Se), the UGLY (Fe, Cu), and the BAD (P, Ca)?

Multiple epidemiological studies have suggested that industrialization and progressive urbanization should be considered one of the main factors responsible for the rising of atherosclerosis in the developing world. In this scenario, the role of trace metals in the insurgence and progression of atherosclerosis has not been clarified yet. In this paper, the specific role of selected trace elements (magnesium, zinc, selenium, iron, copper, phosphorus, and calcium) is described by focusing on the atherosclerotic prevention and pathogenesis plaque. For each element, the following data are reported: daily intake, serum levels, intra/extracellular distribution, major roles in physiology, main effects of high and low levels, specific roles in atherosclerosis, possible interactions with other trace elements, and possible influences on plaque development. For each trace element, the correlations between its levels and clinical severity and outcome of COVID-19 are discussed. Moreover, the role of matrix metalloproteinases, a family of zinc-dependent endopeptidases, as a new medical therapeutical approach to atherosclerosis is discussed. Data suggest that trace element status may influence both atherosclerosis insurgence and plaque evolution toward a stable or an unstable status. However, significant variability in the action of these traces is evident: some - including magnesium, zinc, and selenium - may have a protective role, whereas others, including iron and copper, probably have a multi-faceted and more complex role in the pathogenesis of the atherosclerotic plaque. Finally, calcium and phosphorus are implicated in the calcification of atherosclerotic plaques and in the progression of the plaque toward rupture and severe clinical complications. In particular, the role of calcium is debated. Focusing on the COVID-19 pandemia, optimized magnesium and zinc levels are indicated as important protective tools against a severe clinical course of the disease, often related to the ability of SARS-CoV-2 to cause a systemic inflammatory response, able to transform a stable plaque into an unstable one, with severe clinical complications.

[Infection by non-A, non-B acute viral hepatitis in hospital employees].

The aim of this study is to evaluate the risk of infection of non-A, non-B acute hepatitis (NANB-AH) in hospital employees. Among 593 patients with acute viral hepatitis (AVH), hospital employees were 3/147 (2%) in type A, 19/174 (11%) in type B and 21/272 (8%) in non-A, non-B (NANB). All 43 patients were medical staffs such as doctors, nurses and laboratory technicians. Out of 21 patients with NANB hepatitis of hospital employees, 7 were doctors, 14 nurses and 6 laboratory technicians. Eight of them had preceding accidental needlestick exposures. Out of 17,290 employees of our hospital during 18 years, 27 medical persons developed AVH. They were 2 hepatitis A, 10 hepatitis B and 15 hepatitis NANB. No non-medical staff developed AVH. Out of 15 NANB hepatitis patients, 7 had needlestick accidents 4 to 6 weeks before development of the illness, and all donor patients showed liver diseases. During 3 years (1985 to 1987), there were 116 needlestick accidents in our hospital which happened in medical staffs alone, and 50 of them were NANB hepatitis-related accidents. Three ml of human immune serum globulin (ISG) was administered intramuscurally just after accidents to 23 persons but not to 27 persons. NANB hepatitis were developed in 2 doctors who were not treated with ISG. In conclusion, NANB hepatitis occurred in hospital employees especially in medical staffs.

Effects of iron and copper overload on the human liver: an ultrastructural study.

Iron and copper ions play important roles in many physiological functions of our body, even though the exact mechanisms regulating their absorption, distribution and excretion are not fully understood. Metal-related human pathology may be observed in two different clinical settings: deficiency or overload. The overload in liver cells of both trace elements leads to multiple cellular lesions. Here we report the main pathological changes observed at transmission electron microscopy in the liver of subjects affected by Beta-thalassemia and by Wilson's disease. The hepatic iron overload in beta-thalassemia patients is associated with haemosiderin storage both in Kupffer cells and in the cytoplasm of hepatocytes. Haemosiderin granules are grouped inside voluminous lysosomes, also called siderosomes. Other ultrastructural changes are fat droplets, proliferation of the smooth endoplasmic reticulum and fibrosis. Apoptosis of hepatocytes and infiltration of sinusoids by polymorphonucleates is also detected in beta-thalassemia. Ultrastructural changes in liver biopsies from Wilson's disease patients are characterized by severe mitochondrial changes, associated with an increased number of perossisomes, cytoplasmic lipid droplets and the presence of lipolysosomes, characteristic cytoplasmic bodies formed by lipid vacuoles surrounded by electron-dense lysosomes. In patients affected by Wilson's disease, nuclei are frequently involved, with disorganization of the nucleoplasm and with glycogen inclusions. On the contrary, no significant changes are detected in Kupffer cells. Our data show that iron and copper, even though are both transition metals, are responsible of different pathological changes at ultrastructural level. In particular, copper overload is associated with mitochondrial damage, whereas iron overload only rarely may cause severe mitochondrial changes. These differences underlay the need for further studies in which biochemical analyses should be associated with ultrastructural data, in order to better understand the molecular ways associated with iron- and copper-related pathology at subcellular level.

A developmental approach to drug-induced liver injury in newborns and children.

The liver represents the major site of drug metabolism in humans. The developmental changes that occur in the liver's metabolic activity during fetal life and in the perinatal period are at the basis of the varied sensitivity of human newborns to many drugs. The decreased capacity of the fetal and newborn liver to metabolize, detoxify, and excrete drugs--total cytochrome P450 content in the fetal liver being 30% to 60% of adult values--may explain the prolonged actions of many drugs in the newborn, as well as less their potential toxicity. On the other hand, the low levels of phase I (activation) enzymes, producing more polar reactive and often toxic metabolites, could explain the lower incidence of adverse effects of some drugs reported in newborns. Moreover, the greater capacity of newborns to synthesize glutathione is at the basis of their ability in inactivating many toxic metabolites. Here we review the acute and chronic liver toxicity due to the most widely used drugs in the neonate. We will discuss in detail the biochemical profile of the fetal and neonatal liver, and the toxic metabolites formed during the metabolism of the most widely used drugs in the neonate. The histological picture of liver disease related to the therapeutic use of drugs will be discussed, with particular emphasis on the mode of cell death involved in hepatitis induced by different drugs most frequently utilized in the neonatal intensive care units.

[Comparison of the pituitary-gonadal functions in men and women].

Changes in the levels of several plasma hormones were studied endocrinologically in healthy men and women. A marked decrease in estradiol at age 50 followed by a gradual decline with increasing age was observed in women. Much higher estradiol levels were found in women before age 50. Progesterone levels were quite low after age 40 in both sexes. Testosterone levels were significantly higher in men than in women. In men, however, the levels showed a tendency to decrease after age 75 and those in women demonstrated a significant decrease after age 50. A gradual increase in FSH after age 45 and LH after 60 was found in men, while a striking increase in both was noticed in women at age 50. Higher prolactin levels were observed in men after age 65, but there was no difference according to sex. No changes in the levels of TSH either with increasing age or according to sex were observed. Although similar degrees of pituitary responsiveness to LH.RH test over adult to senile periods were revealed, a somewhat delayed response was seen in men after age 60.

Study of the usefulness and the limits of ultrasonic diagnostic criteria for diagnosis of liver tumours.

We studied the usefulness and the limits of the ultrasonic diagnostic criteria for liver tumours formulated by the Japan Society of Ultrasonics in Medicine (JSUM). 226 cases with liver mass lesions were enrolled in this study. At least one of the criteria reached a value of over 80% for one of the items: sensitivity, specificity, positive predictive value, negative predictive value or overall accuracy. In the differentiation of liver tumours, sharp & smooth boundary, presence of marginal hypoechoic zone, mosaic pattern, starry anechoic area, posterior echo enhancement and lateral shadows were important for HCC. For metastatic liver cancer, potato shape, coarsely irregular boundary, presence of marginal hypoechoic zone, internal target like anecho were important features. The liver pathology of the false negative cases corresponded to: a) liver tissue completely replaced or infiltrated by HCC or metastasis. b) the non-tumour tissue and tumour tissue were isoechoic but also without marginal hypoechoic zone. c) the ultrasonograms of non tumoural areas were modified by calcification of eggs of schistosomiasis and severe fibrosis. It can be concluded that most HCC and metastatic liver cancers over 3 cm in diameter can be diagnosed correctly by the JSUM's criteria. However, complimentary image diagnosis and fine needle biopsy are important to assure the highest diagnostic score in cases with US negative and small tumours.

Ultrastructural studies of hepatocyte cytoskeleton in experimental cholestasis by quick-freezing and deep-etching method.

The ultrastructural association between the cytoskeleton and other organelles was studied by the quick-freezing and deep-etching method in rats treated with alpha-naphthylisothiocyanate (ANIT), or phalloidin, and in rats with obstructive jaundice. Cytoplasmic filaments were classified by measuring their diameters, and actin filaments were identified by specific decoration with myosin subfragment 1 (S1). S1-positive actin filaments and S1-negative intermediate filaments (12-14 nm in diameter) were observed to form a three-dimensional network around bile canaliculi, and were more numerous than in controls, not only in phalloidin-treated rats and rats with obstructive jaundice, but also in ANIT-administered rats. In all cholestatic rats, vesicular structures were also more numerous than in controls in the pericanalicular regions, and were closely associated with the microfilaments and the intermediate filaments. Filaments of a new type were localized between the lamellae of rough-surfaced endoplasmic reticulum and mitochondria, and between the lamellae of Golgi sacs and vesicles. Other thin filaments were also observed within the network of actin filaments. These filaments were 4-6 nm in diameter on replica membranes and were never decorated with S1. They were also directly connected with the canalicular membranes. Cytoskeletal components associated with membrane-bound organelles, including these new filaments, were suggested to be involved in the localization and migration of organelles.