scholarly journals Postnatal alveolar development of the rabbit

2002 ◽  
Vol 93 (2) ◽  
pp. 629-635 ◽  
Author(s):  
Jana Kovar ◽  
Peter D. Sly ◽  
Karen E. Willet

Previous studies of alveolarization have used rats or lambs; however, neither closely reflects human alveolar development. We characterized alveolar development in rabbits ( n = 3–7 /group) at 28 days gestation (dg) to 9 mo to determine whether they followed the human pattern more closely. The right lung was made up of 30% alveolar and 50% duct space at 28 dg to 3 days and of 50 and 30%, respectively, at 14 days to 9 mo. Tissue fraction and alveolar wall thickness decreased by 40% 28 dg to birth. At birth, ∼4.5% of the number of alveoli seen at 9 mo were present, with alveolar number increasing progressively well into adulthood. The rate of alveolar formation was high around birth, decreasing progressively with age. Alveolar volume increased more than twofold (28 dg to birth) and continued to increase postnatally to 16 wk. Surface fraction decreased by 17% (28 dg to 3 days), after which it remained uniform. Our findings suggest that the timing of onset of alveolarization in humans and rabbits is similar and that rabbits may be used to model postnatal influences on alveolar development.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadya Al-Wakeel-Marquard ◽  
Tiago Ferreira da Silva ◽  
Sarah Jeuthe ◽  
Sanaz Rastin ◽  
Frédéric Muench ◽  
...  

AbstractThe right ventricle´s (RV) characteristics—thin walls and trabeculation—make it challenging to evaluate extracellular volume (ECV). We aimed to assess the feasibility of RV ECV measurements in congenital heart disease (CHD), and to introduce a novel ECV analysis tool. Patients (n = 39) and healthy controls (n = 17) underwent cardiovascular magnetic resonance T1 mapping in midventricular short axis (SAX) and transverse orientation (TRANS). Regions of interest (ROIs) were evaluated with regard to image quality and maximum RV wall thickness per ROI in pixels. ECV from plane ROIs was compared with values obtained with a custom-made tool that derives the mean T1 values from a “line of interest” (LOI) centered in the RV wall. In CHD, average image quality was good (no artifacts in the RV, good contrast between blood/myocardium), and RV wall thickness was 1–2 pixels. RV ECV was not quantifiable in 4/39 patients due to insufficient contrast or wall thickness < 1 pixel. RV myocardium tended to be more clearly delineated in SAX than TRANS. ECV from ROIs and corresponding LOIs correlated strongly in both directions (SAX/TRANS: r = 0.97/0.87, p < 0.001, respectively). In conclusion, RV ECV can be assessed if image quality allows sufficient distinction between myocardium and blood, and RV wall thickness per ROI is ≥ 1 pixel. T1 maps in SAX are recommended for RV ECV analysis. LOI application simplifies RV ECV measurements.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
N. B. Kolych ◽  
◽  
N. V. Hudz ◽  

A pathological autopsy was performed on 6 corpses of piglets in the first week of life who died from mycoplasmosis. Examination of the visible mucous membranes revealed hyperemia of the mucous membrane of the nasal cavity and thymus. Simultaneous lesions of the pharyngeal, parotid, cervical, mandibular lymph nodes were noted. They were slightly enlarged, from dark pink to dark red. The heart is irregularly shaped due to the expansion of the right ventricle or the diffuse expansion of all departments. Lungs have doughy consistency, uneven color. In some cases, there are diffuse red areas covering the entire lobe of the lungs, in other cases, there is a defeat of small areas. The liver has a smooth surface, soft or pasty consistency, the parenchyma pattern is slightly smoothed in section. The color of the liver is different: dark red areas, without clear boundaries turn into creamy-clay. Flatulence was a characteristic feature of the stomach and intestines. Catarrhal enteritis was registered in animals, which manifested itself in the form of moderate hyperemia of the intestinal mucosa and serous membranes. Microscopically, there is a significant blood supply to the vessels in the lungs. Alveoli are half fall down, in the form of slit-like lumens. In areas of tissue infiltration by inflammatory infiltrate, the alveolar wall is thickened, alveocytes are in a state of turbid swelling and vacuolar dystrophy, they are impregnated with erythrocytes. Peribronchial pneumonia of lymphocytic character is observed. The liver is in a state of acute venous hyperemia. The central and intraparticle capillaries are sharply dilated and filled with blood in some lobes, and the hepatic beams are compressed accordingly. In the center of other lobes, diffuse infiltration of liver tissue by erythrocytes as a consequence of diapedesis is noted. Hepatocytes are in a state of granular dystrophy. Destructive changes are strongly expressed in the mucous membrane of the small intestine: desquamation of the epithelium, necrosis of epitheliocytes and villi, destruction of crypts. In the brain tissue, there is dilation of the lumens of large and small blood vessels, extracellular and perivascular edema, areas of reactive necrosis.


EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
C Teres ◽  
D Soto ◽  
B Jauregui ◽  
D Penela ◽  
A Ordonez ◽  
...  

Abstract Funding Acknowledgements Dr Teres was funded by Swiss Heartrhythm Foundation Introduction pulmonary vein (PV) reconnections due to gaps on circumferential ablation lines are responsible for atrial fibrillation recurrences after catheter ablation. We sought to analyze the local left atrial wall thickness (LAWT) of PV line gaps at AF redo ablation during real-time catheter positioning. LAWT was measured on the MDCT 3D reconstruction and fused with the LA anatomy using CARTO-merge. Objective To analyze the relationship between local reconnection gaps and the LAWT during AF redo procedures. Methods Single-Center cohort study that included 41 consecutive patients referred for AF redo procedure. All patients had a MDCT prior to the ablation procedure. LAWT maps were semi-automatically computed from the MDCT as the local distance between the LA endo and epicardium. Each PV line was subdivided into 8 segments and mean LAWT was computed. During the procedure, the local gap was defined as the earliest activation site at the reconnected segment of the circumferential PV line (Figure 1A & 1B). Results 41 patients [31 (75.6%) male, age 60 ± 10 years] were included. Mean LAWT was 1.36 ± 0.20 mm. Mean PV circumferential line WT was higher in left PVs than in the right PVs 1.68 ± 0.57 vs. 1.31 ± 0.39 mm p &lt; 0.001 respectively. Mean WT of the reconnected points was 44% higher than the mean WT of the segment where the reconnection was located. Mean reconnection point WT was at the 87th percentile of the circumferential line in the LPVs and at the 76th percentile in the RPVs. The reconnected point WT was higher in the LPVs than RPVs 2.13 ± 1.14 vs. 1.47 ± 0.48 mm p &lt; 0.001 respectively.  The most frequent location for reconnections was the left anterior carina (71%), with a mean WT of 2.24 ± 0.91mm; and the right anterior carina (56%) with a mean WT of 1.57 ± 0.62mm (Figure 2A & 2B). Conclusions Reconnection points were more frequently present in the thicker segments of the PV circumferential line. The most frequently reconnected segment was the anterior carina in both right and left PVs. Atrial wall thickness maps derived from MDCT are useful to guide AF redo procedures. Abstract Figure. 1) Activation & WT map; 2) Segment WT


2007 ◽  
Vol 106 (4) ◽  
pp. 723-735 ◽  
Author(s):  
Guido Musch ◽  
Jose G. Venegas ◽  
Giacomo Bellani ◽  
Tilo Winkler ◽  
Tobias Schroeder ◽  
...  

Background Alveolar overdistension and repetitive derecruitment-recruitment contribute to ventilator-induced lung injury (VILI). The authors investigated (1) whether inflammatory cell activation due to VILI was assessable by positron emission tomography and (2) whether cell activation due to dynamic overdistension alone was detectable when other manifestations of VILI were not yet evident. Methods The authors assessed cellular metabolic activity with [(18)F]fluorodeoxyglucose and regional gas exchange with [(13)N]nitrogen. In 12 sheep, the left ("test") lung was overdistended with end-inspiratory pressure of 50 cm H(2)O for 90 min, while end-expiratory derecruitment of this lung was either promoted with end-expiratory pressure of -10 cm H(2)O in 6 of these sheep (negative end-expiratory pressure [NEEP] group) or prevented with +10 cm H(2)O in the other 6 (positive end-expiratory pressure [PEEP] group) to isolate the effect of overdistension. The right ("control") lung was protected from VILI. Results Aeration decreased and shunt fraction increased in the test lung of the NEEP group. [(18)F]fluorodeoxyglucose uptake of this lung was higher than that of the control lung and of the test lung of the PEEP group, and correlated with neutrophil count. When normalized by tissue fraction to account for increased aeration of the test lung in the PEEP group, [(18)F]fluorodeoxyglucose uptake was elevated also in this group, despite the fact that gas exchange had not yet deteriorated after 90 min of overdistension alone. Conclusion The authors could detect regional neutrophil activation in VILI even when end-expiratory derecruitment was prevented and impairment of gas exchange was not evident. Concomitant end-expiratory derecruitment converted this activation into profound inflammation with decreased aeration and regional shunting.


1996 ◽  
Vol 271 (6) ◽  
pp. R1759-R1769 ◽  
Author(s):  
B. N. Van Vliet ◽  
L. Hu ◽  
T. Scott ◽  
L. Chafe ◽  
J. P. Montani

We investigated cardiac morphometry 6 wk after sinoaortic baroreceptor denervation (SAD) in Long-Evans rats. SAD (n = 19) was associated with an 11% increase in the weight of the left ventricle (LV) plus septum (P < 0.001) and a 39% increase in that of the right ventricular (RV) free wall (P < 0.001), relative to sham-operated rats (n = 18). RV wall thickness was significantly increased in SAD animals, but there was no difference in the LV wall thickness and volumes of the RV and LV between groups. Constrictor responses to methoxamine and dilation responses to acetylcholine were assessed in an in vitro perfused mesenteric circulation preparation, but neither response was affected by SAD. Baroreceptor denervation was associated with marked and significant increases in the variability (2.8-fold) and daily peak (39 mmHg) levels of telemetered mean arterial pressure (MAP) and small (5%) but significant increases in the daily mean MAP level. Our results are consistent with an effect of increased MAP variability on ventricular weight but cannot rule out possible contributions from other mechanisms.


1980 ◽  
Vol 59 (6) ◽  
pp. 485-492 ◽  
Author(s):  
T. C. Amis ◽  
G. Ciofetta ◽  
J. M. B. Hughes ◽  
L. Loh

1. The distribution of regional function in the lungs of six patients with bilateral diaphragmatic paralysis was investigated by continuous inhalation and infusion of the radioactive gases 81mKr and 85mKr during tidal breathing. 2. In the supine and right lateral decubitus postures the vertical distribution of ventilation per unit alveolar volume was less in the dependent zones, the reverse of that found in normal subjects. In the upright posture ventilation was slightly decreased at the lung base. Perfusion per unit alveolar volume was more uniformly distributed than normally in the upright posture, and decreased from superior to inferior in the supine posture. In the lateral decubitus posture, perfusion of the lower lung was greater than that of the upper. Ventilation/perfusion ratios were more uniformly distributed in the patients than in normal subjects, except in the right lateral decubitus posture. 3. Alterations in the distribution of ventilation may be explained in terms of the altered mechanical interaction of chest wall, mediastinal and abdominal contents, with selective use of intercostal and accessory muscles. The effects on the distribution of blood flow are probably related to the low end-expiratory lung volume.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
M Boussoussou ◽  
B Vattay ◽  
B Szilveszter ◽  
M Kolossvary ◽  
M Vecsey-Nagy ◽  
...  

Abstract Introduction The CLOSE protocol is a novel contact-force guided technique for enclosing pulmonary veins in patients with atrial fibrillation (AF). Consistency and lesion contiguity are essential factors for procedural success. We sought to determine whether left atrial (LA) wall thickness (LAWT) and pulmonary vein (PV) dimensions as assessed by coronary CT angiography (CTA) could influence the efficacy of successful first-pass isolation using the CLOSE protocol. Methods In a single center, prospective study we enrolled 94 patients with symptomatic, drug-refractory AF who underwent pre-ablation left atrial CTA and initial radiofrequency catheter ablation between 2019.01–2020.09. The LA was divided into 11 regions when assessing LAWT. Additionally, the diameter and area of the PV orifices were obtained. First pass isolation was recorded separately for the right and left PVs. After the first pass ablation circles were ready, additional ablations were applied in those cases where first pass isolation was not achieved, to reach complete PV isolation. Predictors of successful first pass isolation were determined using logistic regression models that included anthropometrical, echocardiographic and CTA derived parameters. Results A total of 94 patients were included in the analysis with mean CHA2DS2-VASc score of 2.1±1.5 (mean age 62.4±12.6 years, 39.5% female). 61.7% were paroxysmal, 38.3 were persistent AF patients. Mean procedure times were 81.2±19.3 minutes. Complete isolation of all four PVs was achieved in 100% of patients. First-pass isolation rate was 76%, 71% and 54%, for the right PVs, left PVs and all four PVs, respectively. No difference was found regarding comorbidities and imaging parameters between those with and without first pass isolation. LAWT (mean of all 11 regions or separately) had no effect on the procedural outcome (all p&gt;0.05). Out of all assessed parameters, only RSPV diameter was associated with right sided successful PVI on first pass isolation (p=0.04, OR 1.01). Conclusion The use of CLOSE protocol in AF patients resulted in high periprocedural success rate in terms of first pass isolation, independently from the thickness of the LA wall. RSPV diameter could influence the results of first pass isolation. FUNDunding Acknowledgement Type of funding sources: None.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245924
Author(s):  
Tejas R. Karhadkar ◽  
Darrell Pilling ◽  
Richard H. Gomer

SARS-CoV-2 is a single stranded RNA (ssRNA) virus and contains GU-rich sequences distributed abundantly in the genome. In COVID-19, the infection and immune hyperactivation causes accumulation of inflammatory immune cells, blood clots, and protein aggregates in lung fluid, increased lung alveolar wall thickness, and upregulation of serum cytokine levels. A serum protein called serum amyloid P (SAP) has a calming effect on the innate immune system and shows efficacy as a therapeutic for fibrosis in animal models and clinical trials. Here we show that aspiration of the GU-rich ssRNA oligonucleotide ORN06 into mouse lungs induces all of the above COVID-19-like symptoms. Men tend to have more severe COVID-19 symptoms than women, and in the aspirated ORN06 model, male mice tended to have more severe symptoms than female mice. Intraperitoneal injections of SAP starting from day 1 post ORN06 aspiration attenuated the ORN06-induced increase in the number of inflammatory cells and formation of clot-like aggregates in the mouse lung fluid, reduced ORN06-increased alveolar wall thickness and accumulation of exudates in the alveolar airspace, and attenuated an ORN06-induced upregulation of the inflammatory cytokines IL-1β, IL-6, IL-12p70, IL-23, and IL-27 in serum. SAP also reduced D-dimer levels in the lung fluid. In human peripheral blood mononuclear cells, SAP attenuated ORN06-induced extracellular accumulation of IL-6. Together, these results suggest that aspiration of ORN06 is a simple model for both COVID-19 as well as cytokine storm in general, and that SAP is a potential therapeutic for diseases with COVID-19-like symptoms and/or a cytokine storm.


Author(s):  
Uiase Bin Farooq ◽  
Adarsh Kumar ◽  
Shabir Ahmad ◽  
Rajni Chaudhary

The objective of this study was to develop baseline topographical data of landmarks for locating kidneys and urinary bladder and to generate sonographic calliper measurements along with dynamic parameters of these organs. Ultrasonography was performed on 50 native adult (Spiti horses and Himalayan hill mules) healthy unsedated equines of either sex. The thickness, character and echo-architecture of these organs were recorded. The right kidney was found from 15th (±1) intercostal space (ICS) extending upto first lumbar vertebra, both in horses as well as in mules. The height of right kidney varied from 112.7 to 118.3 mm (Mean± SE= 115.6±1.01 mm) and its thickness varied from 58.4 to 71.2 mm (Mean± SE= 64.3±2.37 mm). While in mules height of right kidney varied from 90.7 to 109.2 mm (Mean± SE= of 101.1±3.14 mm) and its thickness varied from 47.3 to 56.8 mm (Mean± SE= 52.3±1.57 mm). The left kidney in horses was found between 16th ICS to 2nd lumbar vertebra, while in mules it was found from 16th ICS to 3rd lumbar vertebra. The height of left kidney varied from 87 to 107.8 mm (Mean± SE= 99.0±3.67 mm) and its thickness varied from 49.5 to 53.8 mm (Mean± SE= 51.8±0.72 mm). In mules the height of left kidney varied from 85.5 to 111.4 mm (Mean± SE= 95.3±2.36 mm) and its thickness varied from 43.4 to 55.7 mm (Mean± SE= 50.6±2.53 mm). During transrectal ultrasonography urinary bladder was observed as an oval to round structure in the caudal ventral abdomen, the wall thickness of urinary bladder varied from 2.7 to 2.8 mm (Mean± SE= 2.74±0.02 mm), 2.4 to 2.7 mm (Mean± SE= 2.62±0.05 mm) in horses and mules respectively. Hence detailed ultrasonographic examination of these organs helped us to compile baseline data, which will be helpful in future in management of the affections of these organs.


2011 ◽  
Vol 368-373 ◽  
pp. 1513-1516
Author(s):  
Chuan Li Chang ◽  
Jian Xue Song

Ten construction sites are chosen as survey places, and several parameters for scaffold designing are collected, such as the wall thickness of steel tube, the weight of three kinds of couplers, the working tighten-moment on belts of couplers. Corresponding to different tighten-moment of the right angle coupler and anti-slipping tests are carried out. Reliability of 97% and wall thickness of 2.7mm should be considered in scaffold designing only about 10% of the practical used couplers comply with the National Code. The working tighten-moment of couplers should be 40 ~ 50N • m, which is up to the load bearing capacity of coupler.


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