Characterization of microplastics in skim-milk powders

The diffusion of microplastics in the food supply chain is prompting public concern as their impact on human health is still largely unknown. The aim of this study was to qualitatively and quantitatively characterize microplastics in skim-milk powder samples (n = 16) from different European countries (n = 8) through Fourier-transform infrared micro-spectroscopy in attenuated total reflectance mode analysis. The present study highlights that the use of hot alkaline digestion has enabled the efficacious identification of microplastics in skim-milk powders used for cheese-making across European countries. The adopted protocol allowed detection of 29 different types of polymeric matrices for a total of 536 plastic particles. The most abundant microplastics were polypropylene, polyethylene, polystyrene, and polyethylene terephthalate. Microplastics were found in skim-milk powders in 3 different shapes (fiber, sphere, and irregular fragments) and 6 different colors (black, blue, brown, fuchsia, green, and gray). Results demonstrate the presence of microplastics in all skim-milk powder samples, suggesting a general contamination. Results of the present study will help to evaluate the impact of microplastics intake on human health.

A thorough analysis of the occurrence, removal and environmental risks of organic micropollutants in a full-scale hybrid membrane bioreactor fed by hospital wastewater

The Urban Wastewater Treatment Directive recent draft issued last October 2022 pays attention to contaminants of emerging concern including organic micropollutants (OMPs) and requires the removal of some of them at large urban wastewater treatment plants (WWTPs) calling for their upgrading. Many investigations to date have reported the occurrence of a vast group of OMPs in the influent and many technologies have been tested for their removal at a lab- or pilot-scale. Moreover, it is well-known that hospital wastewater (HWW) contains specific OMPs at high concentration and therefore its management and treatment deserves attention. In this study, a 1-year investigation was carried out at a full-scale membrane bioreactor (MBR) treating mainly HWW. To promote the removal of OMPs, powdered activated carbon (PAC) was added to the bioreactor at 0.1 g/L and 0.2 g/L which resulted in the MBR operating as a hybrid MBR. Its performance was tested for 232 target and 90 non-target OMPs, analyzed by UHPLC-QTOF-MS using a direct injection method. A new methodology was defined to select the key compounds in order to evaluate the performance of the treatments. It was based on their frequency, occurrence, persistence to removal, bioaccumulation and toxicity. Finally, an environmental risk assessment of the OMP residues was conducted by means of the risk quotient approach. The results indicate that PAC addition increased the removal of most of the key OMPs (e.g., sulfamethoxazole, diclofenac, lidocaine) and OMP classes (e.g., antibiotics, psychiatric drugs and stimulants) with the highest loads in the WWTP influent. The hybrid MBR also reduced the risk in the receiving water as the PAC dosage increased mainly for spiramycin, lorazepam, oleandomycin. Finally, uncertainties and issues related to the investigation being carried out at full-scale under real conditions are discussed.

Enhancing Urban Wastewater Treatment through Isolated Chlorella Strain-Based Phytoremediation in Centrate Stream: An Analysis of Algae Morpho-Physiology and Nutrients Removal Efficiency

The release of inadequately treated urban wastewater is the main cause of environmental pollution of aquatic ecosystems. Among efficient and environmentally friendly technologies to improve the remediation process, those based on microalgae represent an attractive alternative due to the potential of microalgae to remove nitrogen (N) and phosphorus (P) from wastewaters. In this work, microalgae were isolated from the centrate stream of an urban wastewater treatment plant and a native Chlorella-like species was selected for studies on nutrient removal from centrate streams. Comparative experiments were set up using 100% centrate and BG11 synthetic medium, modified with the same N and P as the effluent. Since microalgal growth in 100% effluent was inhibited, cultivation of microalgae was performed by mixing tap-freshwater with centrate at increasing percentages (50%, 60%, 70%, and 80%). While algal biomass and nutrient removal was little affected by the differently diluted effluent, morpho-physiological parameters (F_V/F_M ratio, carotenoids, chloroplast ultrastructure) showed that cell stress increased with increasing amounts of centrate. However, the production of an algal biomass enriched in carotenoids and P, together with N and P abatement in the effluent, supports promising microalgae applications that combine centrate remediation with the production of compounds of biotechnological interest; for example, for organic agriculture.

A New Sustainable Multistep Catalytic Process from Benzene to Caprolactam: Amination, Hydroximation and Beckmann Rearrangement Promoted and Catalyzed by Trifluoroacetic Acid

Here we report some results on a 3 steps benzene caprolactam process via amination, aniline Hydroxymation and Beckmann rearrangement. The amination proceeds with hydroxylamine trifluoroacetate, with 97% of conversion and selectivity of 90%, catalyzed by V compounds. We achieve 98% of conversion and 95% of selectivity in the hydroxymation of aniline in the presence of hydroxylamine trifluoroacetate, sulfonic resin and Pd/C. While in the absence of the resin, hydrogenation of hydroxylamine trifluoroacetate occurs readily to the ammonium salt. The reaction occurs likely by the exchanged hydroxylamine and the aniline reduction intermediate. The use of hydroxylamine trifluoroacetate, instead of the chloride, favors the sustainability of the process by avoiding the ammonium chloride formation. The absence of salt except those derived from the trifluoroacetic acid allows a complete reuse of the trifluoroacetic acid and the only byproduct is ammonium nitrate obtained by resin regeneration. Beckmann rearrangement of the so produced cyclohexanone oxime occurs easily after diethyl ether evaporation and additions of a solution trifluoroacetic acid acetonitrile in high yield and selectivity.

Graphical Abstract

New three steps caprolactam process via benzene amination and aniline hydrogenation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10562-022-04207-9.

Optimal control of epidemic spreading in the presence of social heterogeneity

The spread of COVID-19 has been thwarted in most countries through non-pharmaceutical interventions. In particular, the most effective measures in this direction have been the stay-at-home and closure strategies of businesses and schools. However, population-wide lockdowns are far from being optimal, carrying heavy economic consequences. Therefore, there is nowadays a strong interest in designing more efficient restrictions. In this work, starting from a recent kinetic-type model which takes into account the heterogeneity described by the social contact of individuals, we analyse the effects of introducing an optimal control strategy into the system, to limit selectively the mean number of contacts and reduce consequently the number of infected cases. Thanks to a data-driven approach, we show that this new mathematical model permits us to assess the effects of the social limitations. Finally, using the model introduced here and starting from the available data, we show the effectiveness of the proposed selective measures to dampen the epidemic trends. This article is part of the theme issue 'Kinetic exchange models of societies and economies'.

From agent-based models to the macroscopic description of fake-news spread: the role of competence in data-driven applications

Fake news spreading, with the aim of manipulating individuals' perceptions of facts, is now recognized as a major problem in many democratic societies. Yet, to date, little has been understood about how fake news spreads on social networks, what the influence of the education level of individuals is, when fake news is effective in influencing public opinion, and what interventions might be successful in mitigating their effect. In this paper, starting from the recently introduced kinetic multi-agent model with competence by the first two authors, we propose to derive reduced-order models through the notion of social closure in the mean-field approximation that has its roots in the classical hydrodynamic closure of kinetic theory. This approach allows to obtain simplified models in which the competence and learning of the agents maintain their role in the dynamics and, at the same time, the structure of such models is more suitable to be interfaced with data-driven applications. Examples of different Twitter-based test cases are described and discussed.

Kinetic models for epidemic dynamics with social heterogeneity

We introduce a mathematical description of the impact of the number of daily contacts in the spread of infectious diseases by integrating an epidemiological dynamics with a kinetic modeling of population-based contacts. The kinetic description leads to study the evolution over time of Boltzmann-type equations describing the number densities of social contacts of susceptible, infected and recovered individuals, whose proportions are driven by a classical SIR-type compartmental model in epidemiology. Explicit calculations show that the spread of the disease is closely related to moments of the contact distribution. Furthermore, the kinetic model allows to clarify how a selective control can be assumed to achieve a minimal lockdown strategy by only reducing individuals undergoing a very large number of daily contacts. We conduct numerical simulations which confirm the ability of the model to describe different phenomena characteristic of the rapid spread of an epidemic. Motivated by the COVID-19 pandemic, a last part is dedicated to fit numerical solutions of the proposed model with infection data coming from different European countries.

Removal of Nitrogen and Phosphorus from Thickening Effluent of an Urban Wastewater Treatment Plant by an Isolated Green Microalga

Microalgae are photosynthetic microorganisms and are considered excellent candidates for a wide range of biotechnological applications, including the removal of nutrients from urban wastewaters, which they can recover and convert into biomass. Microalgae-based systems can be integrated into conventional urban wastewater treatment plants (WW-TP) to improve the water depuration process. However, microalgal strain selection represents a crucial step for effective phytoremediation. In this work, a microalga isolated from the effluent derived from the thickening stage of waste sludge of an urban WW-TP was selected and tested to highlight its potential for nutrient removal. Ammonium and phosphate abatements by microalgae were evaluated using both the effluent and a synthetic medium in a comparative approach. Parallelly, the isolate was characterized in terms of growth capability, morphology, photosynthetic pigment content and photosystem II maximum quantum yield. The isolated microalga showed surprisingly high biomass yield and removal efficiency of both ammonium and phosphate ions from the effluent but not from the synthetic medium. This suggests its clear preference to grow in the effluent, linked to the overall characteristics of this matrix. Moreover, biomass from microalgae cultivated in wastewater was enriched in photosynthetic pigments, polyphosphates, proteins and starch, but not lipids, suggesting its possible use as a biofertilizer.

Beta 2-microglobulin Removal by Synthetic Dialysis Membranes. Mechanisms and Kinetics of the Molecule

Beta 2-microglobulin (ß2-m) accumulation represents a possible complication of long term dialysis. It is therefore important to evaluate the capacity of removal of this molecule from the patient by different dialysis membranes. The present study is aimed at evaluating the mechanisms involved in ß2-m removal by three different synthetic membranes: a) highly asymmetric hydrophobic polysulfone (Biosulfane, NMC), b) moderately asymmetric and hydrophobic polysulfone (PS600, Fresenius), c) Polyacylonitrile (AN69HF, Hospal). The adsorption capacity and sieving coefficients of the three membranes for native and labeled ß2-m were studied in vitro utilizing human blood. The amount adsorbed by the membrane was measured by the elution of the molecule obtained with a detergent solution. Clearances, total removal and membrane adsorption were studied in six patients treated in a randomized sequence with the three membranes. For this purpose, plasma and dialysate measurements as well as total collection of spent dialysate and ß2-m elution from the used dialyzers were carried out. Ex novo generation of ß2-m did not take place during in vitro circulation. The molecule was removed by the studied membranes both by filtration and adsorption. The Biosulfane membrane removed ß2-m mostly by adsorption while the PS600 membrane removed ß2-m almost entirely by filtration. Intermediate behaviour was shown by AN69 membrane. Similar quantities of ß2-m were removed from the patients with the three membranes. Total removal could only be precisely measured by adding the quantity of ß2-m eluted from the membrane to the amount recovered in the spent dialysate. Out of total removal, adsorption was more than 90% with Biosulfane, while only 5% with the PS600. These findings contribute to the understanding of the discrepancy found between the clearance measured from the plasma side and that measured from the dialysate side. In conclusion, clearance and sieving measurements for ß2-m cannot be correctly performed unless the capacity of adsorption of the membrane is taken into account.

Phytotoxicity of ionic, micro- and nano-sized iron in three plant species

Potential environmental impacts of engineered nanoparticles (ENPs) can be understood taking into consideration phytotoxicity. We reported on the effects of ionic (FeCl3), micro- and nano-sized zerovalent iron (nZVI) about the development of three macrophytes: Lepidium sativum, Sinapis alba and Sorghum saccharatum. Four toxicity indicators (seed germination, seedling elongation, germination index and biomass) were assessed following exposure to each iron concentration interval: 1.29-1570mg/L (FeCl3), 1.71-10.78mg/L (micro-sized iron) and 4.81-33,560mg/L (nano-iron). Exposure effects were also observed by optical and transmission electron microscopy. Results showed that no significant phytotoxicity effects could be detected for both micro- and nano-sized zerovalent irons, including field nanoremediation concentrations. Biostimulation effects such as an increased seedling length and biomass production were detected at the highest exposure concentrations. Ionic iron showed slight toxicity effects only at 1570mg/L and, therefore, no median effect concentrations were determined. By microscopy, ENPs were not found in palisade cells or xylem. Apparently, aggregates of nZVI were found inside S. alba and S. saccharatum, although false positives during sample preparation cannot be excluded. Macroscopically, black spots and coatings were detected on roots of all species especially at the most concentrated treatments.

Boltzmann-type control of opinion consensus through leaders

The study of formations and dynamics of opinions leading to the so-called opinion consensus is one of the most important areas in mathematical modelling of social sciences. Following the Boltzmann-type control approach recently introduced by the first two authors, we consider a group of opinion leaders who modify their strategy accordingly to an objective functional with the aim of achieving opinion consensus. The main feature of the Boltzmann-type control is that, owing to an instantaneous binary control formulation, it permits the minimization of the cost functional to be embedded into the microscopic leaders' interactions of the corresponding Boltzmann equation. The related Fokker-Planck asymptotic limits are also derived, which allow one to give explicit expressions of stationary solutions. The results demonstrate the validity of the Boltzmann-type control approach and the capability of the leaders' control to strategically lead the followers' opinion.

Body composition and heart rate variability to achieve dry weight and tolerance

Autonomic dysfunction in patients with end- stage renal disease is associated with poor prognosis. Heart rate variability (HRV), determined by the standard deviation of the normal R- R interval, has been reported to be a useful evaluation of cardiac autonomic modulation. The relationship between HRV and hydration status (HS) can be analyzed by whole body bioimpedance spectroscopy. This allows a classification of patients according the combination of HS with predialysis systolic blood pressure. Differences in HRV can be studied in patients with high over hydration, but normal or low blood pressure, with respect to fluid-overloaded/hypertensive patients and normohydrated/normotensive patients. In conclusion, the assessment of the autonomic nervous system response to the hemodialysis treatment in end- stage renal disease patients, classified according to a reliable and quantitative measurement of their fluid overload, could permit better management of both arterial blood pressure and HS.

[A pilot study comparing pulse high volume hemofiltration (pHVHF) and coupled plasma filtration adsorption (CPFA) in septic shock patients]

High-volume hemofiltration (HVHF) and coupled plasma filtration adsorption (CPFA) have shown potential to improve the treatment of sepsis in animals, but there have been no studies comparing these two treatments in humans. Our aim was to compare the hemodynamic effects of HVHF and CPFA in septic shock patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT). We performed a cross-over study enrolling patients with septic shock and AKI who were receiving CRRT. Patients were treated with pulse HVHF and continuous veno-venous hemofiltration (CVV H) on day 1 and CPFA and CVV H on day 2 or vice versa. HVHF was performed for 8-10 hours with a replacement fluid rate of 85 mL/kg/h. CPFA was performed for 8-10 hours with a plasma flow rate of 15%. CVV H was performed for the rest of the day with a replacement fluid rate of 35 mL/kg/h. The primary endpoints were changes in mean arterial pressure, vasopressor requirement (expressed as vasopressor score, VS), and noradrenaline dose after pulse HVHF and CPFA. The two treatments were compared using nonparametric tests. We enrolled 8 patients (median age 70.5 years, SOFA 12.5, SAPS II 69.5). There was a trend towards a reduction in VS with HVHF and CPFA (HVHF p=0.13, CPFA p<0.05). There was no significant difference between the two treatments in terms of percentage change in VS score (p=0.22). The data from this pilot study provide no evidence for a difference in hemodynamic effects between pulse HVHF and CPFA in patients with septic shock already receiving CRRT. A larger sample size is needed to adequately explore this issue.

The Value of Fine Needle Aspiration Cytology in Breast Fibromatosis: Study of Two New Cases and Review of the Literature

We report two new cases of breast fibromatosis studied by needle aspiration cytology observed in a 32-year-old man and a 49-year-old woman. The lesions manifested as palpable, painless, and firm masses of the para-areolar breast soft tissues. Preoperative fine needle cytology revealed scant cellularity, featuring oval and spindle cells with bland nuclei and occasional larger polygonal cells with high nuclear:cytoplasmic ratio. Histologically, interwoven fascicles of spindle cells with bland nuclei, infiltrating the adjacent breast fat, were recognized. Based on available reports in the literature, we concluded that needle aspiration cytology, although not entirely specific, may be a source of important information in patients with breast fibromatosis. In particular, it confidently allows the exclusion of breast cancer and other more common diseases and is useful in planning a surgical approach to the lesion.

Cigarette smoking is a risk factor for nephropathy and its progression in type 2 diabetes mellitus

Cigarette smoking is a risk factor for diabetic nephropathy in Type 1 diabetes (T1DM); a few reports support this possibility in Type 2 diabetes (T2DM) as well. Since heterogeneity among populations could exist, we investigated the association of cigarette smoking and nephropathy, and progression of nephropathy in Italian T2DM patients. A retrospective study was conducted in 273 long-duration T2DM subjects with a 3-year follow-up in the out-patient clinic, and at least one access per year. Albumin excretion rate, serum creatinine, and a number of other parameters implicated in the development of diabetic renal disease were evaluated. Progression of nephropathy was defined as the passage from different stages of renal involvement (no renal derangement, microalbuminuria, proteinuric disease or severe nephropathy). At baseline, 13.2% of the subjects had microalbuminuria, and 3.7% proteinuric disease. Microalbuminuria and proteinuric disease were more frequent in actual smokers than in non- and former smokers (chi2=8.35; p=0.015). Progression of nephropathy was less common in non- and former smokers than in smokers (31 of 134, 23%, and 15 of 67, 22%, and 30 of 72, 42%, respectively; chi2=9.32;p=0.009). From logistic regression analysis, smoking (p=0.0012) emerged as the most important factor associated with progression of nephropathy, followed by packyears (p=0.011), HbA1c mean value at follow-up (p=0.024), and total cholesterol (p=0.038). In conclusion, cigarette smoking is a risk factor for progression of nephropathy also in Italian T2DM patients; reducing or quitting smoking should be part of the therapy or of the preventive measures in these patients and their relatives.

Managing uncertainty in diagnosis of acute coronaric ischemia

The paper presents the reasoning mechanism of COR, a knowledge-based system (KBS) able to provide support for the diagnosis of coronaric ischemia by integrating the interpretation of chest pain, 12-lead ECG, and bio-marker concentrations. Chest pain features are collected interactively through a questionnaire. The ECG signal is acquired in SCP format. Any set of bio-markers can be considered. Data input is incremental and possibly incomplete. Reasoning is based on revised uncertainty calculus, which allows a formal treatment of verbally expressed uncertainty concerning both input data and diagnostic rules. Each diagnosis is supplemented by a linguistic label, expressing the plausibility of the disease identified, given the symptoms observed.

Papillary thyroid carcinoma of the thyroglossal duct cyst: comparative cytohistologic and immunochemical study of 2 new cases and review of the literature

We report a cytohistologic and immunohistochemical study of 2 cases of papillary thyroid carcinoma occurring in a thyroglossal duct cyst. The patients were a 21-year-old woman and a 48-year-old man. Needle aspiration cytology smears were consistent with papillary thyroid carcinoma. The Sistrunk procedure was done. Papillary carcinoma was found within a thyroglossal duct cyst. In 1 case, the tumor spread outside the cyst. Follow-up was uneventful in both patients (2 and 9 years, respectively). Our results would indicate that papillary carcinoma of thyroglossal duct cyst, though indistinguishable from its thyroid homologue, has a more indolent course and could therefore be singled out as a clinicopathologic entity. Needle aspiration cytology reliably assists in planning patient management.

Impact of biofeedback-induced cardiovascular stability on hemodialysis tolerance and efficiency

BACKGROUND

Hypotension is caused by a drop in blood volume during ultrafiltration, followed by vasoconstriction and reduced perfusion in some regions of the body.

METHODS

We carried out a prospective controlled crossover study on 12 hypotension-prone patients with two different modalities: (A) acetate-free hemodiafiltration with standard ultrafiltration control, and (B) acetate-free hemodiafiltration with monitoring of blood volume and automatic biofeedback with machine-driven adjustments on ultrafiltration and dialysate conductivity. We measured urea Kt/V and equilibrated Kt/V (eKt/V), urea rebound, and urea removal. Hypotensive episodes and interventions were recorded.

RESULTS

In group B, fewer hypotensive episodes were recorded (24 out of 72 in group B vs. 59 out of 72 in group A). Saline infusion was required in 57 cases in group A and 15 cases in group B. Urea Kt/V was 1.34 +/- 0.08 in group A and was 1.26 +/- 0.06 in group B; eKt/V was much higher in group B (1.12 +/- 0.05) than in group A (1.03 +/- 008). A significantly higher rebound was observed in group A (14.2 +/- 2.7%) compared with group B (6.4 +/- 2.3%). Discussion. A greater solute sequestration seems to occur during hemodialysis with hypotension. This results in lower eKt/V, enhanced postdialytic rebound, and lower solute removal. Higher efficiency can be observed when dialysis is carried out smoothly and cardiovascular stability is maintained. We conclude that new systems for blood volume monitoring and automatic biofeedback may not only reduce the number of hypotensive episodes during dialysis, but may also contribute to significantly increase the efficacy of the treatment.

Embryonal "Botryoid" rhabdomyosarcoma of the larynx: a clinicopathologic and immunohistochemical study of two cases

Two cases of embryonal rhabdomyosarcoma of the larynx are reported. The tumors occurred in a 16-year-old boy and in a 66-year-old man. They manifested clinically with nonspecific symptoms, including voice hoarseness and sense of throat fullness. Treatment consisted of total and partial laryngectomy, respectively. Grossly, both lesions had an exophytic growth pattern and microscopically featured a proliferation of small round to oval cells. Cell cytoplasms were occasionally stainable and fibrillary. Quite often, tumor cellularity was denser beneath the covering mucosa, recalling a "cambium layer" pattern. Tumor cells immunoreacted for desmin, actins, myoglobin, and sarcomeric actin; no immunostaining was noted for epithelial markers. No further antitumoral treatment was administered after surgery. There has been no recurrence of tumor at 2 and 10 years, respectively. Based on our series and the available literature, it seems that rhabdomyosarcoma of the larynx pursues a less-aggressive course than that seen in the homonimic juvenile or adult soft tissue lesion. Surgery alone appears to be a valid treatment option, especially when a polypoid, or "botryoid" gross pattern, coupled with the embryonal small cell histotype is encountered. In light of these findings, it is suggested that botryoid rhabdomyosarcoma of the larynx may deserve a specific consideration among the various laryngeal mesenchymal malignancies.

Migration of langerhans cells and dermal dendritic cells in skin organ cultures: augmentation by TNF-alpha and IL-1beta

Migration from sites of antigen encounter to lymphoid organs is essential to the strong immunogenic function of dendritic cells (DC). In the skin, migration proceeds through dermal lymphatic vessels and is regulated in an incompletely understood way by inflammatory mediators. We studied the effects of tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) in mouse skin organ cultures by direct enumeration of migrating DC and by immunohistochemistry. (1) Neutralizing antibodies to TNF-alpha and IL-1beta inhibited migration of DC, also in human skin explants (TNF-alpha). (2) TNF-alpha at low concentrations (50 U/mL) and IL-1beta (50-3000 U/mL) augmented migration to about 150% of spontaneous migration. (3) High concentrations of TNF-alpha (5000 U/mL) inhibited migration by approximately 50%. (4) DC migration from skin explants of TNF-alpha/lymphotoxin-alpha double-deficient mice and TNF-receptor type 1 and 2 double knockout mice was not impaired. (5) TNF-alpha effects were neutralized by anti-IL-1beta, and vice versa. We conclude that in normal animals both TNF-alpha and IL-1beta are required for DC migration to occur. In the complete absence of one cytokine (TNF-alpha), however, backup mechanisms step in.

Pulmonary thromboembolism following calf cellulitis: report of an unusual complication of dog bite

We report a case of a 75-year-old woman who died of pulmonary thromboembolism following a dog bite to the calf. The bite caused laceration of the skin and gangrenous cellulitis of leg soft tissues. Six days after hospitalization, the patient died suddenly, despite early antibiotic and heparin administration. Postmortem examination revealed extensive thrombosis of the deep veins of the calf and massive thromboembolism of the main pulmonary arteries.

Pseudoangiomatous hyperplasia of the mammary stroma: true entity or phenotype?

We report the clinical and pathologic features seen in 14 cases of pseudoangiomatous hyperplasia of the mammary stroma. The lesion manifested as a discrete palpable lump in twelve women and two men. The excisional biopsy specimens showed firm, circumscribed grey-tan lesions measuring from 3 to 5.5 cm in largest dimension. Histologic study revealed diffuse, anastomosing, enlongated slits with open lumina, covered by spindle cells with bland nuclei and no mitotic activity. Strong reactivity for vimentin and CD34 was noted. Smooth muscle actin was focally noted in most cases. Immunostains for other markers, including CD31 and factor VIII related antigen was negative. Spindle cells from two cases expressed both estrogen and progesterone receptors. In all the cases, there was some degree of glandular hyperplasia accompanying the stromal changes. Fibroadenoma or fibrocystic disease were also common features. Our study confirms that pseudoangiomatous hyperplasia of mammary stroma represents a proliferation of local myofibroblasts, likely related to a hormonal stimulus. The wide range of associated changes of breast parenchyma further indicates that this lesion may represent a local, non specific change rather than a true clinico-pathologic entity.

Polypoid osteosarcoma of the left atrium: report of a new case with autopsy confirmation and review of the literature

We describe a new case of heart osteosarcoma manifesting as a large polypoid mass of the left atrium. Clinically, the lesion presented with dyspnea, syncopal attacks, and fever. Ultrasound scans of the heart were suggestive of a cardiac myxoma, although some imaging features could retrospectively indicate a malignant neoplasm. In particular, the lesion was relatively immobile, did not show the characteristic myxoma motion during the heart cycle, and extended into the left pulmonary veins. Exploratory thoracotomy showed a nonresectable polypoid mass of the left atrium widely infiltrating the myocardium and the epicardium, histological features of a polymorphic sarcoma. The patient died 5 months after presentation with diffuse metastases. At autopsy, a 5-cm polypoid tumor was seen protruding into the left atrium. Neoplastic infiltration of the atrial myocardium, pericardium, and pulmonary veins was evident. Extensive metastatic deposits were observed in numerous sites, including the skin, lung, liver, and brain. Microscopically, a spindle cell sarcoma forming malignant osteoid was seen, admixed with areas indistinguishable from myxoid and pleomorphic malignant fibrous histiocytoma. This case provides further evidence that although rare, osteosarcoma of the heart usually presents as a polypoid mass of the left atrium and is histologically characterized by conspicuous polymorphism. It is associated with a poor prognosis and rapid appearance of distant metastases. Although at echocardiography it may mimic a myxoma, subtle features such as tumor extension into pulmonary veins and main origin from nonseptal atrial walls suggest the presence of a nonmyxomatous tumor and a preoperatory diagnosis of aggressive malignant disease.

Gestational squamous cell carcinoma of the breast: an unusual mammary tumor associated with aggressive clinical course

We report two cases of squamous carcinoma of the breast detected during the gestational period. One woman was post-partum and lactating; one was in the first trimester of pregnancy. The lesions were clinically palpable, multifocal, and measured more than 5 cm in their largest dimension; both had a cystic appearance. They were treated with radical mastectomy. One patient received pre-operatory chemotherapy. Histologically, the tumors were poorly differentiated squamous cell carcinomas. No areas of ordinary duct differentiation were seen. Lymph nodes contained metastatic squamous carcinoma in both cases. Tumor cells were negative for estrogen and progesterone receptors. Also, they expressed a high proliferative index and several markers of tumor progression, including cErb-B2, p53 protein, bcl-2, and epidermal growth factor receptor. One patient died of tumor 5 months following breast surgery and had extensive metastases proven at autopsy. The other patient had evidence of pulmonary metastases: following cisplatin therapy, she underwent clinical remission. This study shows that squamous carcinoma of the breast may occur in pregnant or lactating women: it appears clinically distinguishable from the non-gestational type that is usually associated with a better prognosis and occurs in peri- or postmenopausal women.

Entry into afferent lymphatics and maturation in situ of migrating murine cutaneous dendritic cells

An important property of dendritic cells (DC), which contributes crucially to their strong immunogenic function, is their capacity to migrate from sites of antigen capture to the draining lymphoid organs. Here we studied in detail the migratory pathway and the differentiation of DC during migration in a skin organ culture model and, for comparison, in the conventional contact hypersensitivity system. We report several observations on the capacity of cutaneous DC to migrate in mouse ear skin. (i) Upon application of contact allergens in vivo the density of Langerhans cells in epidermal sheets decreased, as determined by immunostaining for major histocompatibility complex class II, ADPase, F4/80, CD11b, CD32, NLDC-145/DEC-205, and the cytoskeleton protein vimentin. Evaluation was performed by computer assisted morphometry. (ii) Chemically related nonsensitizing or tolerizing compounds left the density of Langerhans cells unchanged. (iii) Immunohistochemical double-staining of dermal sheets from skin organ cultures for major histocompatibility complex class II and CD54 excluded blood vessels as a cutaneous pathway of DC migration. (iv) Electron microscopy of organ cultures revealed dermal accumulations of DC (including Birbeck granule containing Langerhans cells) within typical lymphatic vessels. (v) Populations of migrating DC in organ cultures upregulated markers of maturity (the antigen recognized by monoclonal antibody 2A1, CD86), but retained indicators of immaturity (invariant chain, residual antigen processing function). These data provide additional evidence that during both the induction of contact hypersensitivity and in skin organ culture, Langerhans cells physically leave the epidermis. Both Langerhans cells and dermal DC enter lymphatic vessels. DC mature while they migrate through the skin.

Pseudomesotheliomatous angiosarcoma: a pleuropulmonary lesion simulating malignant pleural mesothelioma

We report two cases of autopsy confirmed angiosarcoma in adult males, presenting as diffuse pleuropulmonary tumours and simulating malignant mesothelioma. Both the lesions grew along the serosal surfaces and were characterized by variably thick rinds of tissue encasing the lung. The pulmonary parenchyma showed diffuse, dark red, subpleural consolidations and multiple cavitations. Histologically, the lesions were composed by atypical spindle and polygonal, epithelioid cells showing rudimentary vascular differentiation and exhibiting strong positivity for factor VIII, CD31, CD34 and vimentin, We conclude that angiosarcoma may present with preponderant or exclusive involvement of pleura and peripheral lung and that it should be added to the list of tumours capable of simulating malignant mesothelioma.

Beta 2-microglobulin removal by synthetic dialysis membranes. Mechanisms and kinetics of the molecule

Beta 2-microglobulin (beta 2-m) accumulation represents a possible complication of long term dialysis. It is therefore important to evaluate the capacity of removal of this molecule from the patient by different dialysis membranes. The present study is aimed at evaluating the mechanisms involved in beta 2-m removal by three different synthetic membranes: a) highly asymmetric hydrophobic polysulfone (Biosulfane, NMC), b) moderately asymmetric and hydrophobic polysulfone (PS600, Fresenius), c) Polyacylonitrile (AN69HF, Hospal). The adsorption capacity and sieving coefficients of the three membranes for native and labeled beta 2-m were studied in vitro utilizing human blood. The amount adsorbed by the membrane was measured by the elution of the molecule obtained with a detergent solution. Clearances, total removal and membrane adsorption were studied in six patients treated in a randomized sequence with the three membranes. For this purpose, plasma and dialysate measurements as well as total collection of spent dialysate and beta 2-m elution from the used dialyzers were carried out. Ex novo generation of beta 2-m did not take place during in vitro circulation. The molecule was removed by the studied membranes both by filtration and adsorption. The Biosulfane membrane removed beta 2-m mostly by adsorption while the PS600 membrane removed beta 2-m almost entirely by filtration. Intermediate behaviour was shown by AN69 membrane. Similar quantities of beta 2-m were removed from the patients with the three membranes. Total removal could only be precisely measured by adding the quantity of beta 2-m eluted from the membrane to the amount recovered in the spent dialysate. Out of total removal, adsorption was more than 90% with Biosulfane, while only 5% with the PS600. These findings contribute to the understanding of the discrepancy found between the clearance measured from the plasma side and that measured from the dialysate side. In conclusion, clearance and sieving measurements for beta 2-m cannot be correctly performed unless the capacity of adsorption of the membrane is taken into account.

Intrapericardial thymoma: report of two incidental autopsy cases and review of the literature

OBJECTIVES

To report the pathologic features of intrapericardial thymoma and discuss their possible clinical relevance.

DESIGN

Retrospective evaluation of autopsy cases and the available clinical records.

SETTING

A large autopsy population (>31,000 postmortem examinations between 1980 and 1995) in an Italian general hospital.

RESULTS

Two cases of thymoma showing an exclusive intrapericardial growth were retrieved from autopsy files. The patients were 61 and 82 years of age, both were women, and both were referred to the hospital with terminal conditions due to either neoplastic or chronic diseases. Myasthenia gravis and/or immunologic dysfunctions were not noted, although one of the patients had serum hypogammaglobulinemia. Roentgenography showed enlargement of mediastinal profiles and suggested cardiomegaly. At autopsy, tumors were bulky, noninvasive, and from 6 to 10 cm in largest dimension. Histologically, they were spindle cell "medullary" thymomas, frequently showing cell arrangement around microcystic spaces. They were strongly immunoreactive for epithelial markers.

CONCLUSIONS

This study confirms that thymomas may occur in the pericardium. Tumor-related symptoms may be overlooked owing to concomitant heart disease or equivocal instrumental features, especially in the absence of immune system disturbances. Based on these premises, they may deserve a specific distinction in the expanding chapter of ectopic thymomas.

[A critical review of the stable changes in ventricular repolarization in ischemic cardiopathy. A correlation with the angiographic findings]

Unknown is the significance of the abnormalities of repolarization observed at rest in patients with coronary artery disease (CAD) demonstrated by coronary angiography, except for ischemic episodes, myocardial infarction, left ventricular hypertrophy, electrolyte changes or pharmacological interactions. The chronic T wave inversion and ST segment depression are usually considered as an alteration due to ischemia ("chronic myocardial ischemia"); this definition is, in our opinion, erroneous, because myocardial ischemia is an acute episode caused by a sudden lack of balance between demand and availability of myocardial oxygen, corresponding to transient electrocardiographic alterations. Thus, the definition of "chronic myocardial ischemia" referred to stable abnormalities of repolarization is incorrect, because a "chronic" lack of balance between MVO2 and O2 availability would produce necessarily irreversible myocardial damage (necrosis). To contribute to the comprehension of the stable ECG changes at rest, we have selected a group of patients with CAD demonstrated by coronary angiography, presenting stable T wave alterations and ST depression at rest. We have studied the main and regional left ventricular function through radionuclide angiocardiography (ACS). Comparing the abnormalities of repolarization (ECG) on the one hand with angio, EFR and VER on the other, we have obtained different positive correlations, according to the functional parameters considered (EFR and VER). In our study, the lowest positive correlation has been noticed comparing ECG versus angio, VER and EFR (37.5%), while the highest correlation was obtained when ECG was considered versus angio and VER (56.25%). Evaluating ECG versus angio and EFR we have obtained a positive correlation equal to 43.75%. So we have deduced that VER is the functional parameter that better relates to angio and ECG.(ABSTRACT TRUNCATED AT 250 WORDS)

Circadian rhythms of atrial natriuretic peptide, renin, aldosterone, cortisol, blood pressure and heart rate in normal and hypertensive subjects

The occurrence and extent of a circadian rhythm in the circulating concentrations of atrial natriuretic peptide (ANP) are still matters of controversy. Only a few data are available in humans relating the time structure of plasma ANP levels with the circadian patterns of other hormones and cardiovascular variables. In a group of hospitalized normal volunteers (six men and four women, 16-76 years old), and in a group of hospitalized hypertensives (seven men and three women, 18-76 years old), we investigated the circadian variability of ANP and its temporal relationship with the circadian rhythms of blood pressure (BP) and heart rate (HR), and plasma renin activity (PRA), plasma aldosterone (PA) and plasma cortisol (PC) levels, by using a chronobiological inferential statistic method. At the end of a synchronizing period of 1 week (the diet and daily schedule were standardized), the subjects underwent automatic BP and HR monitoring, and blood sampling for 24 h. A statistically significant mean circadian rhythm was demonstrated for ANP, BP, HR, PRA, PA and PC in both normal and hypertensive subjects. The mean circadian acrophase of ANP (calculated to occur at around 04.00 h) anticipated the corresponding acrophases of the other hormones; BP and HR rhythms appeared to be in antiphase with ANP rhythm, i.e. the peak of BP and HR rhythms more or less coincided with the trough in ANP rhythm. A significant increase in the daily levels (assessed by the circadian mesor) of ANP was present in hypertensive subjects when compared with normal controls. In essential hypertension the circadian rhythm of ANP was set at higher circulating levels, but otherwise it was similar to the circadian rhythm found in normals. ANP mesors correlated significantly with renin and aldosterone mesors in normal subjects but not in hypertensive patients. ANP appears to anticipate awakening in its circadian periodic rise. On the basis of the considerable acrophase asynchronism, it seems possible to exclude any causal relations between the periodic changes of ANP and the rhythmic fluctuations of the other hormones that we studied. In contrast, important relations may be hypothesized between ANP levels and BP and HR values, on the basis of their antiphase rhythms.