Lung Surface Research Articles

Intratracheal Administration of siRNA Dry Powder Targeting Vascular Endothelial Growth Factor Inhibits Lung Tumor Growth in Mice

Inhalation therapy using small-interfering RNA (siRNA) is a potentially effective therapeutic strategy for lung cancer because of its high gene-silencing effects and sequence specificity. Previous studies reported that intratracheal administration of siRNA using pressurized metered dose inhalers or nebulizers could suppress tumor growth in murine lung metastatic models. Although dry powder inhalers are promising devices due to their low cost, good portability, and preservability, the anti-tumor effects of siRNA dry powder have not been elucidated. To evaluate the gene-silencing and anti-tumor effects of intratracheally delivered siRNA dry powder, vascular endothelial growth factor-specific siRNA (VEGF-siRNA) dry powder was administered intratracheally to mice with metastatic lung tumors consisting of B16F10 melanoma cells or Lewis lung carcinoma cells. A single intratracheal administration of VEGF-siRNA dry powder reduced VEGF levels in both bronchoalveolar lavage fluid and lung tumor tissue. Furthermore, repeated intratracheal administration of VEGF-siRNA dry powder suppressed the number of visible metastatic foci on the lung surface and tumor area in lung tissues. Taken together, intratracheal administration of siRNA dry powder could be a novel therapeutic strategy for lung cancer through the suppression of specific genes expressed in lung tumor tissue.

Postoperative Bedside Critical Care of Thoracic Surgery Patients.

Postoperative Bedside Critical Care of Thoracic Surgery Patients.

Toward Lung Tumor Localization based on Strain Variability of Lung Surface during Video-Assisted Thoracoscopic Surgery.

Tumor localization, especially in case of minimally invasive lung tumor resection surgery, is extremely challenging due to the continuous motion of the organ. This motion can be troublesome as it results in spatial discrepancy corresponding to preoperative and intraoperative tumor location. In order to characterize lung tissue stiffness for the purpose of lung tumor localization, in this paper, we present a novel characterization approach based on variability in resistance of the healthy region vs. the tumorous region resulting from lung motion. The proposed approach is numerically validated on a Finite Element (FE) model of the lung with varying surface stiffnesses, where higher stiffness represents tumor and lower stiffness corresponds to healthy lung tissue. The numerical simulation validates the sensitivity of our mechanism for different grades of tumors by demonstrating that the strain on the healthy tissue is 31.8 and 67.1 times higher than that on the tumor surface for a selected relative stiffness variation of 3.6x and 24.4x respectively, at a pressure of 1.6 KPa. Additionally, a framework is developed to validate the proposed approach in a video of a video-assisted thoracoscopic surgery (VATS), where multiple landmarks on the lung surface are tracked. This enables us to quantify the motion of points residing on healthy surface and tumorous surface. The motion data is further analyzed to study the relative surface strain, and it is shown that the proposed approach differentiates a tumor from healthy surface.

Sympatho-excitatory response to pulmonary chemosensitive spinal afferent activation in anesthetized, vagotomized rats.

The sensory innervation of the lung is well known to be innervated by nerve fibers of both vagal and sympathetic origin. Although the vagal afferent innervation of the lung has been well characterized, less is known about physiological effects mediated by spinal sympathetic afferent fibers. We hypothesized that activation of sympathetic spinal afferent nerve fibers of the lung would result in an excitatory pressor reflex, similar to that previously characterized in the heart. In this study, we evaluated changes in renal sympathetic nerve activity (RSNA) and hemodynamics in response to activation of TRPV1‐sensitive pulmonary spinal sensory fibers by agonist application to the visceral pleura of the lung and by administration into the primary bronchus in anesthetized, bilaterally vagotomized, adult Sprague‐Dawley rats. Application of bradykinin (BK) to the visceral pleura of the lung produced an increase in mean arterial pressure (MAP), heart rate (HR), and RSNA. This response was significantly greater when BK was applied to the ventral surface of the left lung compared to the dorsal surface. Conversely, topical application of capsaicin (Cap) onto the visceral pleura of the lung, produced a biphasic reflex change in MAP, coupled with increases in HR and RSNA which was very similar to the hemodynamic response to epicardial application of Cap. This reflex was also evoked in animals with intact pulmonary vagal innervation and when BK was applied to the distal airways of the lung via the left primary bronchus. In order to further confirm the origin of this reflex, epidural application of a selective afferent neurotoxin (resiniferatoxin, RTX) was used to chronically ablate thoracic TRPV1‐expressing afferent soma at the level of T1–T4 dorsal root ganglia pleura. This treatment abolished all sympatho‐excitatory responses to both cardiac and pulmonary application of BK and Cap in vagotomized rats 9–10 weeks post‐RTX. These data suggest the presence of an excitatory pulmonary chemosensitive sympathetic afferent reflex. This finding may have important clinical implications in pulmonary conditions inducing sensory nerve activation such as pulmonary inflammation and inhalation of chemical stimuli.

Pulmonary Capillary Hemorrhage Induced by Diagnostic Ultrasound in Ventilated Rats

Pulmonary capillary hemorrhage (PCH) can be induced by diagnostic ultrasound—a potential safety issue. Anesthetized rats were intubated for intermittent positive-pressure ventilation (IPPV) with 0 end-expiratory pressure, +4 cm H2O end-expiratory pressure (PEEP) and −4 cm H2O end-expiratory pressure (NEEP). Rats were imaged at 7.6 MHz with a Philips HDI 5000 ultrasound machine. The output was low (mechanical index [MI] = 0.22) for aiming and then was raised for 5 min in 20 different exposure groups with n = 8. Peak rarefactional pressure amplitudes were measured in water and de-rated for chest attenuation. The PCH areas were measured on the lung surface. At 2.2 MPa, PCH was 9.3 ± 6.6 mm2 for IPPV, 1.6 ± 3.2 mm2 for PEEP (p < 0.001) and 26.8 ± 6.4 mm2 for NEEP (p < 0.001). Thresholds were 1.3 MPa for IPPV, 2.1 MPa for PEEP and 1.0 MPa for NEEP. The small ventilator pressures subtracted or added to trans-capillary stress generated by diagnostic ultrasound pulses, virtually eliminating PCH for PEEP but enhancing PCH for NEEP.

KAI1/CD82 Genetically Engineered Endothelial Progenitor Cells Inhibit Metastasis of Human Nasopharyngeal Carcinoma in a Mouse Model.

BackgroundEndothelial progenitor cells (EPCs) are regarded as promising targeted vectors for delivering therapeutic genes or agents in cancer therapy. The purpose of this study was to investigate the role of intravenously administered KAI1/CD82 genetically transduced EPCs in the tumorigenesis and metastasis of nasopharyngeal carcinoma (NPC).Material/MethodsEPCs were isolated from human umbilical cord blood, expanded in culture, and stably transduced with lentiviral vectors expressing KAI1/CD82. The KAI1/CD82 EPCs were injected intravenously into nude mice bearing human NPC xenografts. Tumor growth and the incidence of liver and lung metastases were observed. Expression of KAI1/CD82 was determined by immunofluorescent staining.ResultsThe NPC model was successfully established. Tumor growth was not suppressed when mice were injected with KAI1/CD82 EPCs (KAI1/CD82 EPCs group) compared with when non-transduced EPCs was present (EPCs group) or the control (1.485±0.234, 1.388±0.204, and 1.487±0.223g, respectively; P>0.05). However, the incidence of lung metastasis was significantly reduced in the KAI1/CD82+ EPCs group compared with the EPCs group and the control group (10%, 55% and 45%, respectively; P=0.005), and there was a significant decrease in the number of metastatic foci on the lung surface (17.50±3.54, 34.27±5.35, and 38.44±9.63 respectively; P=0.007). Moreover, KAI1/CD82 was expressed in lung metastatic foci of the KAI1/CD82 EPCs group, but not in the EPCs group and control group.ConclusionsEPCs can be used as a delivery vehicle for suppressor genes KAI1/CD82 to NPC, and the migration of KAI1/CD82 genetically engineered EPCs can inhibit NPC lung metastasis in a mouse model.

The Development of a Four-Electrode Bio-Impedance Sensor for Identification and Localization of Deep Pulmonary Nodules.

Identifying and localizing of deep pulmonary nodules are among the main challenges that thoracic surgeons face during operations, particularly in thoracoscopic procedures. To facilitate this, we have tried to introduce a non-invasive and safe method by measuring the lung electrical bio-impedance spectrum with a four-electrode array sensor. To study the feasibility of this method, since any change in the depth or diameter of the nodule in the lung tissue is not practical, we used the finite element modeling of the lung tissue and pulmonary nodule to allow changes in the depth and diameter of the nodule, as well as the distance in between the injection electrodes. Accordingly, a bio-impedance sensor was designed and fabricated. By measuring the electrical impedance spectrum of pulmonary tissues in four different specimens with a frequency band of 50kHz to 5MHz, 4 pulmonary nodules at four different depths were identified. The obtained bio-impedance spectrum from the lung surface showed that the magnitude and phase of electrical bio-impedance of the tumoral tissue at each frequency is smaller than that of the healthy tissue. In addition, the frequency characteristic varies in the Nyquist curves for tumoral and healthy lung tissues.

TRPA1‐Induced Pulmonary Spinal Sympathetic Afferent Activation is Attenuated in Rats with Chronic Heart Failure

In a recent preliminary study (Association of the University Anesthesiologists 64th annual meeting, Abstract #1109, 2017), we reported that activation of pulmonary spinal afferents by topical application of bradykinin (BK) and the TRPV1 agonist capsaisin on to lung surfaces (especially on the ventral surface) evokes a previously undocumented potent sympatho‐excitatory reflex that includes increased bood pressure (BP), heart rate (HR) and renal sympathetic nerve activity (RSNA) in urethane‐α‐chloralose anesthetized, vagotomized rats. These data suggested a new pulmonary sympathetic afferent reflex (PSAR) in rats. However, it remains unclear whether pulmonary sympathetic afferents can also be activated by the transient receptor potential ankyrin 1 (TRPA1) agonist, allyl isothiocyanate (AITC). In the current study, we examined the TRPA1‐induced PSAR in both normal and chronic heart failure (CHF) states. After bilateral vagotomy, we applied filter paper (3 × 3 mm) saturated with 30 mM AITC to the ventral lung surfaces to stimulate the PSAR in urethane‐ α‐chloralose anesthetized sham‐operated and CHF (8 weeks post myocardial infarction) rats. We found that application of AITC to the lungs resulted in a biphasic BP response whereas HR and RSNA remained elevated during the AITC application in sham rats (Table 1). Compared to sham rats, AITC caused a predominantly depressor response in CHF rats. The increases in HR and RSNA in response to AITC were also attenuated in CHF rats. These data suggest that activation of the TRPA1 receptor in pulmonary spinal afferents can cause sympatho‐excitation in normal rats whereas this response was blunted in CHF rats. Ongoing studies are validating TRPA1 receptor protein expression in pulmonary sensory neurons in sham and CHF rats.Support or Funding InformationThis work was, in part, supported by grants from the National Heart, Lung, and Blood Institute (1R01HL121012‐01 and 1R01HL126796‐01).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Anatomy of the Respiratory System of the African Grey Parrot (Psittacus erithacus)

The morphology and function of the avian respiratory system has been studied and debated for over a century due to its distinct features, such as: unidirectional airflow, aerodynamic valves, and a volume‐constant lung ventilated by non‐vascularized, compliant air sacs. Intra‐ and interspecific variation in the shape, size, and number of avian bronchi and ventilatory air sacs has been described from gross dissections and latex injections, but little has been done to describe the three dimensional (3D) morphology and variation of the avian respiratory system in situ, largely due to the destructive nature of dissection. This research aims to generate a detailed anatomical description and 3D digital models of the lower respiratory system of the African grey parrot (Psittacus erithacus). Four micro‐computed tomography (micro CT) datasets of deceased P. erithacus specimens were segmented to produce 3D tetrahedral surface meshes of the pulmonary tree, lung surfaces, air sac surfaces, and skeleton. The anatomical models were then validated via latex injections. Bronchial tree measurements of P. erithacus (n=8) were collected for intraspecific and interspecific comparisons with two other well‐studied archosaurian taxa: the ostrich (Struthio camelus, n=10) and the American alligator (Alligator mississippiensis, n=10). Similarities in the relationships between the carina and the first four large secondary airways of the bronchial tree suggest a role in maintaining unidirectional airflow patterns in these taxa that would have been present in a common ancestor. In some P. erithacus specimens, the cervical air sacs were found to have a broad, thin, and sub‐sternal expansion that extended caudally to encapsulate more than half the ventral abdominal viscera. In another specimen, the right and left abdominal air sacs merged along the midline to form a single, common abdominal sac. These results suggest that the shape and extent of the air sacs in P. erithacus are more variable than previously described for other avian taxa. The models, which will be made available as a detailed 3D digital anatomical atlas through the Grey Parrot Anatomy Project, will likely become an invaluable resource to avian veterinarians for surgical planning.Support or Funding InformationAssociation of Avian Veterinarians (AAV) Research Grant AwardThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Influence of dietary nitrate supplementation on lung function and exercise gas exchange in COPD patients

BackgroundDuring exercise as pulmonary blood flow rises, pulmonary capillary blood volume increases and gas exchange surface area expands through distention and recruitment. We have previously demonstrated that pulmonary capillary recruitment is limited in COPD patients with poorer exercise tolerance. Hypoxia and endothelial dysfunction lead to pulmonary vascular dysregulation possibly in part related to nitric oxide related pathways. PurposeTo determine if increasing dietary nitrate might influence lung surface area for gas exchange and subsequently impact exercise performance. MethodsSubjects had stable, medically treated COPD (n = 25), gave informed consent, filled out the St George Respiratory Questionnaire (SGRQ), had a baseline blood draw for Hgb, performed spirometry, and had exhaled nitric oxide (exNO) measured. Then they performed the intra-breath (IB) technique for lung diffusing capacity for carbon monoxide (DLCO) as well as pulmonary blood flow (Qc). Subsequently they completed a progressive semi-recumbent cycle ergometry test to exhaustion with measures of oxygen saturation (SpO2) and expired gases along with DLCO and Qc measured during the 1st work load only. Subjects were randomized to nitrate supplement group (beetroot juice) or placebo group (black currant juice) for 8 days and returned for repeat of the above protocol. ResultsExhaled nitric oxide levels rose >200% in the nitrate group (p < 0.05) with minimal change in placebo group. The SGRQ suggested a small fall in perceived symptom limitation in the nitrate group, but no measure of resting pulmonary function differed post nitrate supplementation. With exercise, there was no influence of nitrate supplementation on peak VO2 or other measures of respiratory gas exchange. There was a tendency for the exercise DLCO to increase slightly in the nitrate group with a trend towards a rise in the DLCO/Qc relationship (p = 0.08) but not in the placebo group. The only other significant finding was a fall in the exercise blood pressure in the nitrate group, but not placebo group (p < 0.05). ConclusionDespite evidence of a rise in exhaled nitric oxide levels with nitrate supplementation, there was minimal evidence for improvement in exercise performance or pulmonary gas exchange surface area in a stable medically treated COPD population.

Pleural fluid may pose no measurable effect on lung stiffness in lung ultrasound surface wave elastography

Lung ultrasound surface wave elastography (LUSWE) was developed as a non-invasive tool for assessing pulmonary fibrosis. In this research, the effect of the fleural fluid on surface wave speed measurement of the lung is studied. Low-cost sponges [J. Ultrasound Med. 2017; 36, 2133], as good lung phantoms, were used in this study. The ultrasound transmission gel was used to simulate the pleural fluid. A harmonic vibration was generated at sponge surfaces using a shaker at 100, 150, and 200 Hz. The sponge surface wave speeds were measured with a 6 MHz ultrasound probe for both with and without a thin layer gel. The ultrasound features of A and B-lines were clearly observed in every sponge model in our experiment. The surface wave speeds for the sponges with the gel were indistinguishable from those without the gel for each frequency. The surface wave speeds were faster at higher excitation frequencies which is consistent with our patient study results. It was conclude that the pleural fluid may not affect the lung surface wave speed measurement based upon our lung phantom sponge models.

Effects of general anesthesia with or without epidural block on tumor metastasis and mechanisms.

The present study aimed to assess whether different anesthesia methods (general anesthesia and general anesthesia combined with epidural block) were associated with tumor metastasis during the perioperative period and the possible molecular mechanisms of tumor metastasis. A rat hepatoma tumor xenograft model was constructed via the subcutaneous injection of Morris hepatoma 3924A cells into the upper axillary fossa. General anesthesia and general anesthesia combined with epidural block prior to hepatectomy were conducted on tumor-bearing rats. The average numbers of metastatic nodules on the lung surface were calculated in the different groups and the presence of abdominal lymph node metastases, rate of malignant ascites and abdominal wall-implanted nodules were recorded. Blood samples were collected from the orbits of rats immediately prior to surgery and at 2, 7 and 30 days following surgery. Plasma levels of interferon-γ, transforming growth factor-α and vascular endothelial growth factor (VEGF) were measured. Finally, the expression of phosphorylated signal transducer and activator of transcription-3 and phosphorylated VEGF were measured by western blot analysis. The results of this analysis demonstrated that tumor metastasis was greatly suppressed when the rats underwent general anesthesia combined with epidural block prior to hepatectomy, compared with general anesthesia alone. The results of cytokine quantification and western blot analysis revealed that the anti-metastatic effect of general anesthesia combined with epidural block may have been mediated by inhibition of STAT3 and the relevant cytokines.

Development of the pulmonary pleura with special reference to the lung surface morphology: a study using human fetuses.

In and after the third trimester, the lung surface is likely to become smooth to facilitate respiratory movements. However, there are no detailed descriptions as to when and how the lung surface becomes regular. According to our observations of 33 fetuses at 9–16 weeks of gestation (crown-rump length [CRL], 39–125 mm), the lung surface, especially its lateral (costal) surface, was comparatively rough due to rapid branching and outward growing of bronchioli at the pseudoglandular phase of lung development. The pulmonary pleura was thin and, beneath the surface mesothelium, no or little mesenchymal tissue was detectable. Veins and lymphatic vessels reached the lung surface until 9 weeks and 16 weeks, respectively. In contrast, in 8 fetuses at 26–34 weeks of gestation (CRL, 210–290 mm), the lung surface was almost smooth because, instead of bronchioli, the developing alveoli faced the external surfaces of the lung. Moreover, the submesothelial tissue became thick due to large numbers of dilated veins connected to deep intersegmental veins. CD34-positive, multilayered fibrous tissue was also evident beneath the mesothelium in these stages. The submesothelial tissue was much thicker at the basal and mediastinal surfaces compared to apical and costal surfaces. Overall, rather than by a mechanical stress from the thoracic wall and diaphragm, a smooth lung surface seemed to be established largely by the thick submesothelial tissue including veins and lymphatic vessels until 26 weeks.

Video-assisted thoracoscopic diagnosis of trapped lung in malignant pleural effusions

PURPOSE. The aim of this study is to present the role of video-assisted thoracoscopy to assess the ability of the lung to expand in malignant pleural effusions. METHODS. The survey was conducted for a 3-year period in 13 patients with histologically diagnosed malignant pleural effusion and trapped lung. In each of the patients video-assisted thoracoscopy was performed. RESULTS. Two reasons for trapped lung were identified. In 10 of the patients it was due to multiple metastatic nodules. In 3 cases the cause was a diffuse fibrotic involvement of the lung resulting from the metastatic process.CONCLUSIONS. Our research confirmed two causes of trapped lung in malignant pleural effusions: multiple metastases on the lung surface and diffuse lung fibrosis, induced by the metastatic process, with the increased role of multiple metastases on the lung surface

Reduction of Pulmonary Air Leaks with a Combination of Polyglycolic Acid Sheet and Alginate Gel in Rats

Postoperative air leaks remain a major cause of morbidity after lung resection. This study evaluated the effect of a combination of polyglycolic acid (PGA) sheet and alginate gel on pulmonary air leaks in rats. Four pulmonary sealing materials were evaluated in lung injury: fibrin glue, combination of PGA sheet and fibrin glue, alginate gel, and combination of PGA sheet and alginate gel. With the airway pressure maintained at 20 cmH2O, a 2 mm deep puncture wound was created on the lung surface using a needle. Lowering the airway pressure to 5 cmH2O, each sealing material was applied. The lowest airway pressure that broke the seal was measured. The seal-breaking pressure in each experimental group was fibrin, 10.4 ± 6.8 cmH2O; PGA + fibrin, 13.5 ± 6.5 cmH2O; alginate gel, 10.3 ± 4.9 cmH2O; and PGA + alginate, 35.8 ± 11.9 cmH2O, respectively. The seal-breaking pressure was significantly greater in the PGA + alginate gel group than in the other groups (p < 0.01). There were no significant differences among the other three groups. Alginate gel combined with a PGA sheet is a promising alternative to fibrin glue as a safe and low-cost material for air leak prevention in pulmonary surgery.

Pathological investigations on an outbreak of avian Tuberculosis (AvTB) in a Turkey flock in Dhaka

A flock of four-week old turkey chicks showed clinical signssuch as fatigue, in-appetence, gasping and eventual death after having a very brief illnesses. Postmortem examinations showed non-mineralized elevated nodules in the lung, costal membranes and inner surface of the abdominal cavity. Histopathologic findings were typical of avian tuberculosis, with necrotic debris in the lung parenchyma. The lesions were found to be surrounded by epithelioid macrophages, lymphocytes, and multinucleated giant cells. Laboratory confirmation was made based on lesions and using Ziehl-Neelsen(ZN) acid-fast stain. The presence of granulomas in the lungs of the infected chicks may suggest that the exposure to the infective agent was via the respiratory route rather than the alimentary route. The case was diagnosed as tuberculus peri-bronchial pneumonia.

Inhibition of p38 and ERK1/2 pathways by Sparstolonin B suppresses inflammation-induced melanoma metastasis

BackgroundCancer related inflammation plays a fatal role in the metastatic process, which can foster tumor growth, angiogenesis and dissemination. Sparstolonin B (SsnB), derived from Chinese medicine of the tubers of Scirpus yagara, is a TLR2 and TLR4 antagonists. It has exhibited multiple activities of anti-inflammatory, anti-cancer, anti-obesity and anti-hepatitis. However, whether SsnB is involved in the regulation of inflammation-induced tumor metastasis is not well elucidated. PurposeThe aim of this study was to investigate the effectiveness of SsnB as a treatment of inflammation-induced tumor metastasis and identify the underlying mechanisms of its anti-tumor metastatic activity. MethodThe anti-tumor metastatic activity in vitro was estimated by MTT, wound-healing assay, matrigel invasion analysis and extracellular matrix adhesion assay. Mice lung metastasis and hepatic metastasis experiments were performed to assess the activities in vivo. Lungs or livers were weighed and the number of metastatic nodules was determined after mice were sacrificed. The levels of pro-inflammatory cytokines in the serum, lungs and livers were detected by using enzyme-linked immunosorbent assay (ELISA). Micro-metastasis nodules in lungs or livers were analyzed by histological examination. Immunohistochemistry and western blot analysis were conducted to determine protein expression. ResultHerein, SsnB dose-dependently inhibited cell migration and invasion in mouse melanoma B16 cells with or without stimulation of lipopolysaccharide (LPS), Pam3csk4 or molecules from damaged tumor cells (DTC-Ms). The expression of matrix metalloproteinases (MMP)-2 was also significantly abated by SsnB in LPS-modulated B16 cells. And SsnB reduced LPS-activated B16 cells adhesion to extracellular matrix components collagen I and fibronectin in a dose-dependent manner. In vivo, SsnB obviously attenuated LPS-activated pulmonary metastasis in mice by reduction the number of metastatic nodules on the lung surfaces, lung weight and levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in serums and lungs. Moreover, in experimental hepatic metastasis model mice, SsnB remarkably repressed LPS-stimulated the number of metastatic nodules along with liver weight; and SsnB significantly suppressed LPS-activated increase levels of TNF-α and IL-6 in livers. Immunohistochemistry analysis indicated that SsnB inhibited the expression of TLR4 in livers. Furthermore, SsnB remarkably blocked p38 and ERK1/2 signaling pathway in LPS-induced B16 cells. P38 and ERK1/2 signaling silencing, using BIRB0796 (small molecular inhibitor of p38 MAPK) and PD184352 (inhibitor of MEK1/2 kinases that activate ERK1/2), significantly abated LPS-induced migration and invasion of B16 cells. ConclusionThe present study reports a novel use of SsnB in mitigating TLRs ligands-induced melanoma metastasis by inhibition of p38 and ERK1/2 pathway.

Retrospective Study of Pneumony by Aelurostrongylus abstrusus in Cats

Background: Aelurostrongylus abstrusus is a lungworm of cats with worldwide distribution. The adult forms of this parasite live in terminal bronchioles and alveoli, and can cause an asymptomatic disease or predominantly respiratory clinical signs, which can be occasionally cause of death. The aim of this study is to describe the epidemiological and pathological findings of infection by A. abstrusus through a necropsy retrospective study.Materials, Methods &amp; Results: the necropsy records from the Department of Veterinary Pathology of the Universidade Federal do Rio Grande do Sul were recovered and cats diagnosed with lungworm by Aelurostrongylus abstrusus were selected since January 1998 until December 2015. General data, such as age, sex, breed, clinical signs, and macroscopic lesions, were analyzed and compiled. The histological slides were reviewed by optical microscopy and detailed the microscopic aspects. In this study, were identified 22 cats with varying degrees of lungworm by A. abstrusus, and in 45.5% of the cases, this was the cause of death. Most part of the cats were mixed breed (19/22), and there were no sex predisposition. The age of the cats ranged from four months to 11 years old, and the most frequent age group was three to six years, with nine cases reported. In 37.5% of the cases were reported respiratory clinical signs, such as dyspnea and nasal discharge, and in 62.5%, clinical signs were not specific. The gross findings of the lungs ranged from reddish, or yellowish or white areas, and presence of multiples small, firm, and whitish nodules, measuring more than two centimeters in diameter, with multifocal distribution in the lung surface. Histologically, there was varied amount of parasites in different stages in the alveolar spaces, associated with the inflammatory infiltrate composed of lymphocytes, plasma cells, macrophages, neutrophils and occasional multinucleated giant cells, and hypertrophy and hyperplasia of the pulmonary smooth muscle and the wall of the arteries.Discussion: Aelurostrongylus abstrusus is the principal parasite of lung of cats, with worldwide distribution. In this study, we observed that 40.9% of cases were reported as of 2012, and may be due to a larger propagation of definitive intermediate and paratenic hosts, climate changes and/or the increase of rearing cats, and the consequent increase of hospital routine. Agreeing with the others authors, there is no sex predilection, but differ in the age group, in to the present study, the most frequent age group was between “3 to 6 years” of age (52.9%). The gross findings observed were similar to those described by other authors. Histologically was observed varied amount of parasites, and the degree of inflammatory infiltrate were very similar, but with a slight difference in discrete infiltration (36.4%). Others researchers have identified predominantly severe inflammatory infiltrate (57.9%). Hypertrophy and hyperplasia of pulmonary smooth muscle and the wall of the arteries was moderate (50%), however, in previous studies were severe. The diagnosis of aelurostrongilosis through parasitological tests have proven the occurence this lung parasite in the study region, highlighting the importance of this study by adding epidemiological and pathological data on the disease.

Location of Ruptured Bullae in Secondary Spontaneous Pneumothorax.

BackgroundThe surgical treatment of secondary spontaneous pneumothorax (SSP) can be complicated by fragile lung parenchyma. The preoperative prediction of air leakage could help prevent intraoperative lung injury during manipulation of the lung. Common sites of bulla development and ruptured bullae were investigated based on computed tomography (CT) and intraoperative findings.MethodsThe study enrolled 208 patients with SSP who underwent air leak control through video-assisted thoracoscopic surgery (VATS). We retrospectively reviewed the sites of bulla development on preoperative CT and the rupture sites during VATS.ResultsOf the 135 cases of right-sided SSP, the most common rupture site was the apical segment (31.9%), followed by the azygoesophageal recess (27.4%). Of the 75 cases on the left side, the most common rupture site was the apical segment (24.0%), followed by the anterior basal segment (17.3%).ConclusionThe azygoesophageal recess and parenchyma along the cardiac border were common sites of bulla development and rupture. Studies of respiratory lung motion to measure the pleural pressure at the lung surface could help to determine the relationship between cardiogenic and diaphragmatic movement and bulla formation or rupture.

An Ultrasound Surface Wave Technique for Assessing Skin and Lung Diseases

Systemic sclerosis (SSc) is a multi-organ connective tissue disease characterized by immune dysregulation and organ fibrosis. Severe organ involvement, especially of the skin and lung, is the cause of morbidity and mortality in SSc. Interstitial lung disease (ILD) includes multiple lung disorders in which the lung tissue is fibrotic and stiffened. The purpose of this study was to translate ultrasound surface wave elastography (USWE) for assessing patients with SSc and/or ILD via measuring surface wave speeds of both skin and superficial lung tissue. Forty-one patients with both SSc and ILD and 30 healthy patients were enrolled in this study. An external harmonic vibration was used to generate the wave propagation on the skin or lung. Three excitation frequencies of 100, 150 and 200 Hz were used. An ultrasound probe was used to measure the wave propagation in the tissue non-invasively. Surface wave speeds were measured on the forearm and upper arm of both left and right arm, as well as the upper and lower lungs, through six intercostal spaces of patients and healthy patients. Viscoelasticity of the skin was calculated by the wave speed dispersion with frequency using the Voigt model. The magnitudes of surface wave speed and viscoelasticity of patients' skin were significantly higher than those of healthy patients (p < 0.0001) for each location and each frequency. The surface wave speeds of patients' lung were significantly higher than those of healthy patients (p < 0.0001) for each location and each frequency. USWE is a non-invasive and non-ionizing technique for measuring both skin and lung surface wave speed and may be useful for quantitative assessment of SSc and/or ILD.