Metastases to the Pituitary Gland: Histological Patterns of Spread and Review of the Literature

Few studies have focused on histological patterns of metastatic spread to the pituitary gland. We review our experience and that in the literature, 1970–present. Departmental cases, 1998–2021, were assessed for anterior versus posterior gland and/or capsular involvement and cohesive tumor obliterating underlying pituitary architecture versus metastatic cells filling pituitary acini with relative acinar preservation. Eleven autopsy/15 surgical cases, including 2 metastases to pituitary adenomas, were identified. Cohesive/obliterative patterns predominated histologically in both surgical and autopsy cases, but acinar filling by metastatic cells was extensive in 3/26 cases, focal in 5/26, and had resulted in initial erroneous impressions of atypical pituitary adenoma/pituitary carcinoma in 1 case and pituitary adenoma with apoplexy in another, likely due to focusing on necrotic areas in the specimen where the acinar pattern had been broken down and not appreciating nearby areas with acinar filling by metastatic cells. Although most pituitary metastases produce readily identifiable cohesive/obliterative patterns, diagnostic challenges remain with the less frequently seen “acinar filling” pattern. A dichotomy exists between patients with symptomatic pituitary metastases occurring early in the disease course and requiring surgical excision versus patients in whom asymptomatic small pituitary metastases are found incidentally at autopsy, the latter almost invariably in late disease stages, with widely disseminated metastatic disease.

Effect of Left Ventricular Restrictive filling pattern on survival in ischemic cardiomyopathy: Implications for surgical ventricular restoration.

Background: To evaluate the effects of baseline left ventricular restrictive filling pattern (RFP; E/A>2) in ischemic cardiomyopathy (ICM) patients on prognosis. Methods: Patient data was retrospectively analyzed over a period of 4.5 years to determine the effect of Echocardiographic factors on survival and re-admission for heart failure. Results: There were 102 ICM patients who had baseline RFP. We identified two sub-groups based on geometric phenotypes of left ventricular eccentric remodeling and dilated remodeling based on the relative wall thickness (RWT >0.34 or <0.34). The patients with preserved RWT had significantly more dilated ventricles ( LVIDd and LVIDs), greater pulmonary artery systolic pressures (PASP), greater diatolic dysfunction (E/A) and less left ventricular ejection fraction (LVEF); p<0.001. The number of deaths was higher in the reduced RWT patients, as were the number of re-admissions, although the time to survival and time to re-admission was not significant. Conclusions: In this pilot study on ICM patients in advanced heart failure with baseline RFP, the presence of preserved RWT indicative of eccentric remodelling demonstrated a better clinical outcome, leading to a hypothesis that the eccentric remodelling LV phenotype might benefit with SVR.

Correlation of choriocapillaris hemodynamic data from dynamic indocyanine green and optical coherence tomography angiography

To investigate the correlation between posterior pole choroidal blood flow evaluated with digital subtraction indocyanine green angiography and enface optical coherence tomography angiography (OCTA). Imaging in animal study. The anatomy of 2 cynomogulus monkeys was studied. Each monkey was given a 0.75 mg/kg injection of indocyanine green in the saphenous vein. The dynamic angiographic filling sequence was recorded at 15 frames per second using the Heidelberg Spectralis. After image registration, sequential frame subtraction was used to image the dye front moving through the choroid. The OCTA was obtained by frame averaging nine separate choriocapillaris slab flow images obtained from the Zeiss Plex Elite 9000. Posterior pole choriocapillaris filling pattern in relation to the choriocapillaris anatomy as imaged by OCTA. In the posterior pole, the choriocapillaris fills in the pattern of discrete units with variable sizes and shapes. The cycle of dye filling begins in the peripapillary area and progresses toward the periphery in a wavelike manner. This filling pattern repeats in a cyclical manner, consistent with the cardiac cycle. OCTA shows a uniform mesh of vessels. While OCTA shows a uniform meshwork appearance of the choriocapillaris, the dynamic dye angiography suggests an irregular configuration of functional units partitioned by pressure gradients as opposed to structural boundaries. Disturbance of local perfusion pressure within choroidal vasculature may result in abnormal flow patterns, which could be evaluated in the clinic using commercially available equipment.

Experimental study on tensile strength of copper microparticles filled polymer composites printed by fused deposition modelling process

Purpose The purpose of this paper is to investigate the variables of the fused deposition modelling (FDM) process and improve their effect on the mechanical properties of acrylonitrile butadiene styrene (ABS) components reinforced with copper microparticles. Design/methodology/approach In the experimental approach, after drying the ABS granule, it was mixed with copper microparticles (at concentrations of 5%, 8% and 10%) in a single screw extruder to fabricate pure ABS and composite filaments. Then, by making the components by the FDM process, the tensile strength of the parts was determined through tensile strength tests. Taguchi DOE method was used to design the experiments in which nozzle temperature, filling pattern and layer thickness were the design variables. The analysis of variance (ANOVA) and signal-to-noise analysis were conducted to determine the effectiveness of each FDM process parameter on the ultimate tensile strength of printed samples. Following that, the main effect analysis was used to optimize each process parameter for pure ABS and its composite at different copper contents. Findings The study allows the layer thickness and filling pattern had the highest effects on the ultimate tensile strength of the printed materials (pure and composite) in the FDM process. Moreover, the results show that the ultimate tensile strength of the ABS composite containing 5% copper was nearly 12.3% higher than the pure ABS part. According to validation tests, the maximum error of experiments was about 0.96%. Originality/value In this paper, the effect of copper microparticles (as filling agent) was investigated on the ultimate tensile strength of printed ABS material during the FDM process.

Low-consistency refining of CTMP targeting high strength and bulk: effect of filling pattern and trial scale

Chemithermomechanical pulp (CTMP) is often used in central layers of multiply paperboards due to its high bulk and strength. Such a CTMP should consist of well-separated undamaged fibres with sufficient bonding capacity. The basic objective of this work is to optimize process conditions in low-consistency (LC) refining, i. e. to select or ultimately develop new optimal LC refiner filling patterns, in order to produce fibrillar fines and improve the separation of fibres from each other while preserving the natural fibre morphology as much as possible. Furthermore, the aim is to evaluate if this type of work can be done at laboratory-scale or if it is necessary to run trials in pilot- or mill-scale in order to get relevant answers. First stage CTMP made from Norway spruce (Picea abies) was LC refined in mill-, pilot- and laboratory-scale trials and with different filling patterns. The results show that an LR1 laboratory refiner can favourably be used instead of larger refiners in order to characterize CTMP with regard to tensile index and z-strength versus bulk. A fine filling pattern resulted in CTMP with higher tensile index, z-strength and energy efficiency at maintained bulk compared to a standard filling pattern.

Low Stroke Volume Index in Healthy Young Men Is Associated with the Incidence of Acute Mountain Sickness after an Ascent by Airplane: A Case-Control Study

Background. The aims of this study were to explore the characteristics of left ventricular (LV) functional changes in subjects with or without acute mountain sickness (AMS) and their associations with AMS incidence. Methods. A total of 589 healthy men were enrolled and took a trip from Chengdu (500 m, above sea level (asl)) to Lhasa (3700 m, asl) by airplane. Basic characteristics, physiological data, and echocardiographic parameters were collected both at Chengdu and Lhasa, respectively. AMS was identified by the Lake Louise Questionnaire Score. Results. The oxygen saturation (SpO2), end-systolic volume index, end-diastolic volume index (EDVi), stroke volume index (SVi), E-wave velocity, and E/A ratio were decreased, whereas the heart rate (HR), ejection fraction, cardiac index (CI), and A-wave velocity were increased at the third day after arrival, as evaluated by an oximeter and echocardiography. However, AMS patients showed higher HR and lower EDVi, SVi, CI, E-wave velocity, and E/A ratio than AMS-free subjects. Among them, SVi, which is mainly correlated with the changes of EDVi and altered LV filling pattern, was the most valuable factor associated with AMS incidence following receiver-operator characteristic curves and linear and Poisson regression. Compared with subjects in the highest SVi tertile, subjects in the middle SVi tertile showed higher multivariable Incidence Rate Ratios (IRR) for AMS with higher incidences of mild headache and gastrointestinal symptoms, whereas subjects in the lowest SVi tertile showed even higher multivariable IRR with higher incidences of all the symptoms. Conclusions. This relatively large-scale case-control study revealed that the reduction of SVi correlated with the altered LV filling pattern was associated with the incidence and clinical severity of AMS.

From diastolic dysfunction to exercise intolerance: an in silico simulation study on the phenotypic markers of heart failure with preserved ejection fraction

Background Left ventricular (LV) diastolic dysfunction, i.e. impaired LV relaxation function and/or increased LV stiffness, has been hypothesized to be responsible for at least part of the exercise intolerance in heart failure with preserved ejection fraction (HFpEF). Yet the mechanisms remain largely unknown. Purpose To determine in silico if and how abnormal LV diastolic function causes reduction in maximum cardiac output (COmax), i.e. exercise intolerance. Methods We used a cardiovascular model (CircAdapt) to simulate the effects of impaired LV relaxation and increased LV myocardial stiffness on cardiac hemodynamics. The model was initialized using a reference simulation with hypertension (systolic blood pressure: 150 mmHg) and concentric LV hypertrophy (LV wall mass: +25%). Impaired LV relaxation was introduced by increasing tau from 35 ms to 65 ms. LV stiffness was increased by increasing LV end-diastolic elastance from 0.15 mmHg/ml to 0.60 mmHg/ml and 2.00 mmHg/ml (moderate and severe LV stiffness, respectively). In each simulation, LV ejection fraction (LVEF), E/A ratio and mean left atrial (LA) pressure (mLAP) was assessed. To evaluate the effect on exercise tolerance, COmax was determined by gradually increasing cardiac output and heart rate in a predefined manner until mLAP exceeded 35 mmHg. Results In all simulations, LVEF remained unchanged and preserved (i.e. 60%). In rest, impaired LV relaxation decreased E/A ratio from 1.1 to 0.8 (impaired filling pattern) and increased mLAP from 7.2 mmHg to 8.0 mmHg (Figure top: gray vs. orange). Total LV filling time was reduced at rest, reducing diastolic reserve capacity and thereby of COmax, by 15% compared to the reference (Figure bottom: gray vs. orange). Moderate LV stiffness increased E/A ratio to 1.1 (pseudo-normal filling pattern) and mLAP to 15.0 mmHg (Figure top: gray vs. red). COmax was reduced by 40% due to a steep increase of mLAP with exercise intensity. Severe LV stiffness increased E/A ratio to 2.2 (i.e. restrictive filling pattern), but resulted in a non-physiological mLAP of 40 mmHg at rest. However, when combining moderate LV stiffness with LA dysfunction (i.e. reduced LA contractility and increased LA stiffness) also led to restrictive filling pattern (E/A ratio &gt;2.0) with mLAP 19 mmHg (Figure top: red vs. dashed blue). COmax reduced most severely by 53%, emphasizing the importance of LA function in LV diastolic dysfunction (Figure bottom: gray vs. dashed blue). Conclusions Through variations in LV and LA function, we linked the progression of LV diastolic dysfunction to LV and LA properties. Increased LV stiffness, more than impaired LV relaxation, is associated with substantially reduced exercise tolerance. The combination of LV and LA dysfunction led to the most severe exercise intolerance. Our unique in silico framework enables future studies to investigate other potential cardiac and vascular mechanisms underlying exercise intolerance in HFpEF. Figure 1 Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This work was funded by the Netherlands Organisation for Scientific Research and the Dutch Heart Foundation.