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PubMed2005

Partitioning of airway and parenchymal mechanics in unsedated newborn infants.

The recent trend toward development of noninvasive methods that can accurately evaluate the lung periphery has particular relevance for the predominantly parenchymal nature of neonatal respiratory disease. Concerns regarding the safety of sedating newborn (especially preterm) infants have also stimulated a drive toward measurements obtained during natural sleep. This study aimed to adapt existing methodology for the low-frequency forced oscillation technique to obtain partitioned measurements of airway and parenchymal mechanics during unsedated, quiet sleep in newborn infants without a history of previous respiratory disease. A face mask was positioned over the infant's mouth and nose and a brief (4-5 s) breathing pause was induced by evoking the Hering-Breuer reflex via end-inspiratory occlusion at raised lung volume (airway opening occluded at 2 kPa). Airway opening pressure and flow were measured while a pseudorandom noise (2-14 Hz) was applied to the airway. Acceptable pulmonary impedance data were collected in 11 of the 12 infants studied (34.1-42.6 wk postmenstrual age, 1.9-3.9 kg body weight) on 17 (total of 20) occasions. Airway parameters (resistance and inertance) and respiratory tissue parameters were calculated from the resultant impedance spectra. Tissue resistance and tissue elastance decreased with increasing body length albeit at different rates such that hysteresivity (tissue resistance/tissue elastance) also decreased. There was a trend toward reduction in airway resistance with increasing length. Measurements of lung function are feasible in the unsedated newborn infant using low-frequency forced oscillations and confirm the important contribution of tissue resistance to lung mechanics in the developing lung.

Airway Resistance↗

PubMed1977

Carcinoid tumors, vascular elastosis, and ischemic disease of the small intestine.

Ischemic enteritis or infarction occurred in four of 15 patients who had carcinoid tumors of the small intestine. All four, in addition, had elastic vascular sclerosis of the mesenteric vessels. Both arteries and veins were involved, and the change occurred in the region of tumor deposit. In none of the cases was the tumor occluding the lumen of the vessels, nor was there any evidence of thrombosis. Similar elastosis is seen in cancers of the colon, stomach, and breast, and occurs also with thermal injury and irradiation. The findings of the present study would suggest a direct rather than a humoral effect. It would appear that cancer cells exert an inductive effect on the fibroblast or smooth-muscle cell in vascular walls, with excess production of elastic tissue.

Adult↗

PubMed1995

Study of the elastic fibres' framework of the rat lung.

A combination of intravascular resin injection and formic acid incubation was used to study the three-dimensional organization of the elastic fibres of the adult rat lung by scanning electron microscopy (SEM). After SEM observations, the same samples were further processed for transmission electron microscopy (TEM) in order to confirm the presence of the elastic fibres and to complement some aspects of its surface morphology observed under the SEM. Complementary studies by light microscopy (LM) and TEM using specific histochemical methods for the elastic fibres were also performed. The SEM study clearly demonstrated that the cast of the microvasculature acted as a scaffold to preserve the in vivo arrangement of the easily collapsible elastic tissue. The methodology used allowed the observation of a fine framework of elastic fibres representing remnants of the alveolar walls in close association with the capillaries interwoven with the network of elastin. Each thick elastic fibre was composed of a bundle of thin fibres. Some of these thin fibres separated from the main fibre, join other fibres, giving the appearance of an anastomosing net. The interwoven network of elastin and its proximity with the capillaries suggests that the distensibility of the alveolar wall should contribute to the subtle rhythmical change of the alveolar microcirculation at each respiratory movement. On the sub-pleural region of the lung, the elastic fibres were observed forming a continuous and fine mesh network. The elastic fibres linking the walls of the intrapulmonary conducting airways, the vessels wall and the alveolar and sub-pleural elastic network establish an interrelated and interlaced continuous framework, certainly with great physiological implications to the overall process of the mechanics of the lung respiratory function. The methodology applied was a useful tool in order to study the spatial organization of the pulmonary elastic fibres, its branching and close relation with the other lung structures.

Animals↗

PubMed2006

Evaluation of histological techniques for quantifying haemodialysis arteriovenous (AV) graft hyperplasia.

BACKGROUND: Assessing treatment efficacies for preventing haemodialysis arteriovenous (AV) graft stenosis requires a reproducible method for quantifying intimal hyperplasia. We identified sources of variability in three histological methods for assessing hyperplasia in a porcine AV graft model. METHODS: Carotid-jugular synthetic grafts were placed in pigs. After explantation at 3-6 weeks, the tissue was stained with haematoxylin and eosin (H&E), Masson's trichrome or elastic tissue Van Gieson (EVG) stains and examined histologically. Hyperplasia at the anastomosis of 14 grafts was quantified using three different methods, each by four blinded observers. These methods were visual scoring, ratio of intima-to-media surface area (I/M ratio), and ratio of intra-graft hyperplasia to graft surface area (H/G ratio) at the graft-vessel interface. RESULTS: The EVG stain proved superior in delineation of the elastic lamina yet quantification of the intimal and medial layers was still often difficult. This is illustrated by the greater inter-observer median coefficient of variances (CV) found using the I/M ratio method (intimal area CV=13.7%; medial area CV=32.7%; I/M ratio CV=44.0%) than with the H/G method (intra-graft hyperplasia area CV=7.3%, graft area CV=5.3%; H/G ratio CV=6.9%) or by visual scoring (CV=26.8%). The H/G ratios correlated positively with visual scores (r=0.941; P=0.0007; n=14) and the I/M ratio (r=0.719; P=0.0095; n=14). While hyperplasia was seen in both native vessel and graft lumen, in only one of the 14 anastomoses was the degree of hyperplasia greater in the native vessel than in the graft lumen, suggesting that the degree of hyperplasia occurring within the graft lumen predicted the total hyperplasia around the anastomosis. CONCLUSIONS: The H/G method for assessing hyperplasia is preferred in a porcine model of AV graft because it is quantitative, less variable and does not require the delineation of the elastic lamina, although it infrequently underestimates the total hyperplasia that occurs.

Animals↗

PubMed2005

Collagen and elastic system in the remodelling process of major types of idiopathic interstitial pneumonias (IIP).

AIMS: Structural remodelling in acute and chronic idiopathic interstitial pneumonia (IIP) has been extensively investigated, but little attention has been directed to the elastic tissue in these situations. The aim of this study was to determine whether elastic deposition accompanies collagen deposition in the four major histological patterns of IIP: diffuse alveolar damage (DAD), organizing pneumonia (OP), non-specific interstitial pneumonia (NSIP) and usual interstitial pneumonia (UIP). METHODS AND RESULTS: We measured, by image analysis, the content of fibres of the collagenous and elastic systems of the alveolar septum in histological slides of open lung biopsies, using the picrosirius-polarization method and Weigert's resorcin-fuchsin stain, respectively. Five groups were studied: 10 cases of DAD; nine cases of OP; nine cases of NSIP; and 10 cases of UIP. Four normal lungs were used for comparison. The content of collagen fibres was significantly higher in UIP when compared to DAD, NSIP, OP and normal lung. The content of elastic fibres was increased in comparison with normal lungs but this was not significantly different among the histological patterns. CONCLUSION: Acute and chronic IIP cause a similar increase in the collagen and elastic contents of the lungs, representing a process of 'fibroelastosis' rather than an exclusive process of fibrosis. A profibrogenic mechanism is responsible for the unparallelled collagen augmentation observed in UIP subjects, the nature of which is yet to be determined.

Aged↗

PubMed1988

Scanning electron microscopy of elastic networks from the bifurcation region of guinea pig carotid arteries.

We isolated the elastic network from the bifurcation region of guinea pig carotid arteries by treatment with hot alkali and examined its adventitial and adluminal components by SEM. The thickness of networks from common and external carotid arteries averaged 87.5 microns (+/- 6.9 SD) and from the carotid sinus averaged 46.8 microns (+/- 2.4 SD). The networks consisted of a mesh of elastic tissue that became a continuous sheet, 2 microns thick, which formed the internal elastic lamina (IEL). The IEL was fenestrated; the perforations varied in number among the vessels (occipital greater than carotid sinus greater than common = external carotid), and some were spanned by delicate elastic fibers. The IEL's adluminal surface was a smooth membranous sheet, which in some specimens bore unidirectional loose fibers, or was composed of tightly fused bundles of uni- or multidirectional fibers. The interior region of the cranial carotid sinus contained unique blister-like structures and dense clusters of fenestrations, together with a honeycomb-like mesh near the ascending pharyngeal artery. The outer, adventitial elastic layer consisted of a network of loose elastic fibers that were fused with the inner layers. We conclude that the structural differences noted among the common and external carotid arteries and carotid sinus are related to the sinus's unique pressure-sensing functions.

Animals↗

PubMedDate not supplied

Aortic valve replacement with the Unique Suture Line Stentless USL porcine valve: A new, simple, and safe stentless valve implantation technique.

The Stentless USL, Unique Suture Line porcine valve, is a stentless bioprosthesis developed following the advantages of the studies of the physiology of the aortic root as a functional unit. The direct suturing of the porcine tissue on the soft and elastic tissue of the host's aortic annulus and root gives the bioprosthesis the possibility to follow the physiological movements of the natural valve during the cardiac cycle. For the same reason, there is decreased stress on the valve tissue, especially at the commissural level. There is less technical demand for surgeons who have limited experience with the freehand or miniroot technique due to the limited availability of the homografts because the Stentless USL valve can be implanted with the same technique used with a conventional stented valve. The implant technique used for the Stentless USL valve has advantages, especially in the small aortic calcified annulus in elderly patients where the freehand technique can be difficult and the second suture line can be dangerous (i.e., coronary ostium near the aortic ring or in calcified aortic wall). Our experience with this stentless valve in approximately 200 patients (> 70 years old) shows it to have excellent hemodynamic results even in small valve sizes. The use of this valve and the simple implantation technique avoids the need for complicated aortic root enlargement procedures.

Aged↗

PubMed1979

Staining properties of aldehyde fuchsin analogs.

This investigation was designed to clarify the role of the aldehyde component of aldehyde fuchsin in its staining reactions. Several aldehyde fuchsin analogs were prepared by using different aldehydes. The staining quality of these analogs and pararosaniline-HCl was compared with that of aldehyde fuchsin prepared with paraldehyde in the usual way. The major findings of this investigation include: 1) Aldehyde fuchsin staining of nonoxidized pancreatic B cells requires a stain prepared with either paraldehyde or acetaldehyde. 2) An aldehyde moiety is required for aldehyde fuchsin staining of strong tissue anions. 3) Staining of elastic tissue with aldehyde fuchsin analogs resembles staining of strong tissue anions more than staining of nonoxidized pancreatic B cells. Possible reaction mechanisms of aldehyde fuchsin with tissue substrates are discussed.

Aldehydes↗

PubMed1990

Type II pneumocytes in mixed cell culture of human lung: a light and electron microscopic study.

Alveolar Type II epithelial cells dedifferentiate rapidly in vitro. Studies with animal tissue suggest that cell-cell and extracellular matrix-cell interactions are important in the retention of Type II cell morphology in vitro. Thus, in this study with human tissue, alveolar Type II cells, alveolar macrophages, and spindle cells were prepared from the same sample of lung (obtained following lobectomy for cancer, n = 3), cocultured on glass cover slips or tissue culture plastic, and studied by light microscopy with scanning (SEM) and transmission (TEM) electron microscopy for 8 days. The primary cell isolates contained approximately 45% Type II cells; the remainder were macrophages or unidentifiable cells. Clusters, made up of a single layer of cuboidal Type II cells around a central core of connective tissue (largely collagen and some elastic tissue), formed above a monolayer of spindle cells. The Type II cells were morphologically similar to those seen in vivo. The cells were still cuboidal at 8 days but had lost their lamellar bodies, which were released into the medium via the apical surface. The clusters increased in size with time (area, microns 2: day 1, 29(5-143) x 10(2); day 8, 63(10-311) x 10(2); mean(range); p less than 0.02) without changing in number per culture, suggesting Type II cell proliferation. This may have been due to factors produced by the other cells and adherence to the extracellular matrix (ECM); (free collagen fibers, present in the original preparation, spindle cells, and/or Type II cells could be responsible for presence of ECM). We propose this as a useful model for the study of human Type II epithelial cells in vitro.

Cell Differentiation↗

PubMed2002

Treatment of periodontal disease in a patient with Ehlers-Danlos syndrome. A case report and literature review.

BACKGROUND: Ehlers-Danlos syndrome (EDS) designates a heterogeneous group of connective tissue disorders characterized by skin elasticity, tissue fragility, and chronic joint pain. Dental findings have been reported with some types of EDS. This case report describes the periodontal findings in a patient with a previously undiagnosed EDS type VIII. METHODS: Diagnostic aids utilized included microbial testing, histological examination, gingival crevicular fluid (GCF) analysis for the levels of C-telopeptide pyridinoline cross-links (ICTP), and genetic counseling. Periodontal treatment consisted of mechanical debridement and adjunctive antibiotic therapy. RESULTS: Genetic counseling and clinical presentation confirmed the diagnosis of EDS type VIII. Periodontal treatment led to marked clinical improvements and GCF levels of the bone resorptive marker ICTP were significantly reduced. The patient and her siblings are currently pursuing appropriate medical care and genetic counseling. CONCLUSION: Periodontal involvement may lead to the diagnosis of an underlying systemic condition. Identification of suspected etiological factors of periodontal disease may prove critical for the general well-being of some patients.

Alveolar Bone Loss↗

PubMedDate not supplied

[Breast reconstruction by pedicled transverse rectus abdominis myocutaneous flap].

Reconstruction of the amputated breast in female patients after surgical management of breast carcinoma is possible with the use of autologous tissue, synthetic implants, or by combining autologous tissue and synthetic materials. Autologous tissue provides soft and sufficiently elastic tissue, which is usable for breast reconstruction and eventually obtains original characteristics of the surrounding tissue on the chest wall. The use of the TRAM flap for breast reconstruction was introduced in 1982 by Hartrampf, Scheflan, and Black. The amount of the TRAM flap tissue allows breast reconstruction in the shape most adequate to the remaining breast. The possibilities of using the TRAM flap as pedicled myocutaneous flap or as free TRAM flap make this flap a superior choice for breast reconstruction in comparison with other flaps.

Adult↗

PubMed1992

[Pseudoxanthoma elasticum. A rare cause of upper digestive hemorrhage].

Pseudoxanthoma Elasticum (PXE) is a rare inherited elastic tissue disorder with degeneration of elastic fibres involving mainly skin, eyes and the cardiovascular system. Upper gastro-intestinal hemorrhage occurs in 13% of cases and is often resistant to non-surgical methods of treatment. One case report involving recurrent gastric hemorrhage in a young patient with PXE and treated with total gastrectomy is presented. Diagnosis was made, after surgery, by biopsy of skin lesions of the neck. The characteristics of PXE are reviewed and the case is discussed.

Adolescent↗

PubMed1985

[Histological and biochemical studies of collagen in human uterine leiomyomas].

Forty eight human uteri including normal group (16 cases), adenomyosis group (5 cases) and myoma group (27 cases) were studied to clarify the pathogenesis of uterine leiomyomas on the viewpoint of the collagen metabolism. The leiomyomas in the myoma group were histologically divided into the three types; cellular leiomyoma type (7 cases), fibromyoma type (14 cases) and hyaline degeneration type (6 cases). After collagen contents were determined, collagen molecules were extracted and purified, then they were examined by the techniques of SDS-polyacrylamide gel electrophoresis and amino acid analysis. The results were as follows: The collagen content of the myoma group (62.3 +/- 2.7%, mean +/- S.E.) was higher than those of the normal group (48.5 +/-3.2%) and the adenomyosis group (52.0 +/- 5.2%) (P less than 0.05), and it was consistent with the histological collagen amount in the three types of the myoma group respectively. The normal group, the adenomyosis group and the myoma group contained mainly type I collagen [alpha 1 (I)2 alpha 2] and a little type III collagen [alpha 1 (III)3], but alpha 1(III)/alpha 1(I) ratio decreased in order of the normal group (20.6 +/- 0.3%), the adenomyosis group (16.4 +/- 0.2%) and the myoma group (12.9 +/- 0.4%); the cellular leiomyoma type (15.8 +/- 0.2%), the fibromyoma type (12.4 +/- 0.2%) and the hyaline degeneration type (10.5 +/- 0.6%) (P less than 0.001). Decrease of the type III collagen was related to decrease of the tissue elasticity and increase of the tissue firmness. Though hydroxylation ratio of proline showed no remarkable change, hydroxylation ratio of lysine in the myoma group (26.8 +/- 0.5%) was higher than those in the normal group (23.4 +/- 0.4%) (P less than 0.001) and the adenomyosis group (24.3 +/- 0.9%) (P less than 0.05). In the three types of myoma group, its ratio of the cellular leiomyoma type (28.8 +/- 1.1%) was higher than that of the fibromyoma type (25.8 +/- 0.5%) (P less than 0.05). This suggests that intermolecular, rather than intramolecular, cross-linking formation was accelerated in the collagen metabolism of uterine leiomyomas. In conclusion, it was suspected that these abnormalities in the collagen metabolism led to the development of the uterine leiomyoma.

Adolescent↗

PubMed1977

The surgical pathology of thoracic aortic aneurysms.

In 63 resected thoracic aortic aneurysms, the commonest histological finding (45 cases, 71.4%) was cystic medionecrosis. These cases formed two groups, 29 with widespread fragmentation and loss of elastic tissue (elastopathy) and 16 cases without elastopathy who were older and included most of the 18 cases of dissecting aneurysms. Thirteen patients had the Marfan syndrome, 10 showing cystic medionecrosis with elastopathy, indistinguishable from the cases with no Marfan stigmata although partial 'dissections' were mainly found in the Marfan patients, Histological appearances ranged from normal to complete loss of media. Cystic changes in muscle fibres apparently preceded elastic fragmentation. Fourteen cases (22%) had aortitis: 4 were syphilitic and 3 of other known aetiology. In 7 patients the aetiology of the inflammatory process was unknown and appearances included granulomatous infarct-like lesions and necrotizing aortitis or changes indistinguishable histologically from syphilis.

Adult↗

PubMed1981

The urethral syndrome: morphological studies.

Tissue removed at Richardson urethroplasty from 50 patients with the urethral syndrome, together with material obtained from the urethras of 44 cadavers, was examined in an attempt to elucidate the pathological basis for this syndrome. There was a significant increase in fibrous tissue in the urethrovaginal septum, accompanied by a loss of smooth muscle fibres and focal clumping of elastic tissue, in patients with the urethral syndrome.

Collagen↗

PubMed1991

Linear focal elastosis. An ultrastructural study.

We studied an 86-year-old Japanese man with linear focal elastosis. The lesions were asymptomatic yellow striae in the lumbar region, histologically composed of massive, well-demarcated basophilic fibers that stained positively with elastic tissue stains. Electron microscopy revealed fine, reticular or granular electron-dense materials, and elastic fiber microfibril-like materials in the matrix, in addition to numerous mature and immature elastic fibers. These findings suggest that active elastogenesis was occurring in the lesions. The four cases reported so far have the three common features of age, sex, and lesion location.

Actin Cytoskeleton↗

PubMed1980

The fine structure of smooth muscle cells and their relationship to connective tissue in the rabbit portal vein.

The smooth muscle of rabbit portal vein was studied by electron microscopy with particular emphasis on the mechanical linkage between the muscle cells and on the distribution of connective tissue. The media of this vein is composed of inner circular and outer longitudinal muscle layers which are orientated almost perpendicularly to each other. The muscle of the inner circular layer shows very irregular contours with much branching and anastomosing of the cytoplasmic processes, which often make membrane contacts with neighbouring cells to form an extensive network of cytoplasmic processes. The muscle cells of the outer longitudinal layer are arranged in densely packed bundles and are spindle-shaped, with no branching processes. Opposing dense areas from neighbouring cells, with variable gap distances (30--100 nm) and close membrane contacts (intermediate junctions) with a gap of 11 nm were observed in both circular and longitudinal muscle layers. In the terminal regions of muscle cells in both circular and longitudinal layers a specialized anchoring structure was present which was closely related to extracellular elastic tissue. Muscle cells in the longitudinal layer showed the most elaborate structure, the tapering end of the muscle cell showing a honeycomb-like structure penetrated by columns of connective tissue compounds. The functional implications of these structures are discussed.

Animals↗

PubMed1996

Increased elafin expression in cystic, dysplastic and neoplastic oral tissues.

Expression of human leukocyte elastase inhibitor, elafin, otherwise known as skin-derived antileukoproteinase inhibitor (SKALP), was investigated in normal and abnormal oral tissues using a specific anti-SKALP rabbit antiserum. Weak staining was observed in keratinizing epithelia of normal oral mucosa but not in non-keratinizing mucosa. Increased expression was also observed in the suprabasal layers of dysplastic oral epithelia and in well-differentiated squamous cell carcinoma, but not in basal cell carcinoma. A uniform strong expression was observed in all supra-basal layers of odontogenic keratocyst epithelia, except in regions where inflammatory infiltrate was adjacent to keratocyst epithelia. In contrast, elafin expression in a small number of dentigerous cysts and ameloblastomas was more patchy. The increased levels of elafin in keratocyst epithelia and dysplastic tissue may be a cellular homoeostatic response to generate a protective barrier preventing proteolytic degradation of underlying elastic tissue.

Ameloblastoma↗