Layer Of Fibrous Connective Tissue Research Articles

Histomorphological and histochemical study of the fallopian tube during pregnancy and post-partum of the cape hare rabbit (Lepus Capensis)

This research was investigate the Anatomical and Histochemical structure of uterine tube during period of pregnancy and postpartum in cap hare rabbits. Eighteen female rabbits were used. The target samples were processing with paraffin embedding technique the tissue sections stained with H&E stain, and Masson's trichrom stain. Results; The length and weight of the uterine tube were (91.31 ± 0.72mm), (0.53 ±0.01g) at pregnancy. While. its (84.76 ±0.22mm), (0.41 ±0.01g) at post-partum. The infundibulum has a funnel-shaped end. Simple mucosal folds are bordered with pseudo stratified columnar epithelium. The lamina propriea-sub-mucosa is made up of connective tissue that is both vascular and cellular. The ampulla was highly vascularized and had a twisted appearance. The mucosal folds of the ampulla were lined by pseudo stratified columnar epithelium, which consisted of three cell types: mucous secretory cells, non-secretory cells and basal cells. The lamina propria was a thin layer of fibrous connective tissue that exposed a significant amount of fibroblast. The isthmus was short and straight at post-partum, and it was held in place by the mesosalpinx. Mucosal folds in the tunica mucosa are mild and short.

Microscopic and ultramicroscopic structure of typical chordae tendineae of the human’s left ventricle bicuspid valve

Objective – to determine the features of the micro- and submicroscopic structure of typical chordae tendineae of the mitral valve of the human heart.Materials and methods. This study was made on preparations of 35 human hearts, in particular the chordae tendineae of the bicuspid valves of the left ventricles of children and people of early and middle adulthood using the methods of light and electron microscopy.Results. The study of typical chordae tendineae of the mitral valve leaflets was made using the microscopic method and the method of electron microscopy. The areas where the chordae tendineae diverge from the papillary muscles, the middle third of the chordae tendineae, and the place of attachment of the chordae tendineae to the mitral valve leaflets were studied. Chordae tendineae are covered with endothelium from all sides. A peripheral collagen-elastic layer of loose fibrous connective tissue is localized under the endothelium, along the entire perimeter of the chordae tendineae and it differs in structure in different parts of the chordae at the submicroscopic level. Bundles of densely packed collagen fibers, which are oriented rectilinearly along the chordae, form the core of the chordae tendineae. Bundles of striated cardiac typical muscle cells are localized in areas where the chordae tendineae origin from the papillary muscles. It was found that in the composition of the chordae tendineae of children the cellular component in the fibrous connective tissue predominates during comparing the typical chordae tendineae of different aged people.Conclusions. This morphological study made it possible to obtain new information and to clarify the data that are already known to morphologists on the micro- and submicroscopic structure of typical chordae tendineae of the mitral valve of the human heart. We found that differences in the histological structure are more typical for the areas of origin of typical chordae tendineae from the papillary muscles and areas of their attachment to the leaflets of the mitral valve. The diameter of the core of the chordae tendineae increases and the thickness of the loose peripheral collagen-elastic layer decreases with age. The received data can serve as a theoretical basis for the further comparative morphological and clinical studies of the mitral valve of the human heart. That, in turn, will facilitate to an increasing the level of diagnostic, to improve methods of prevention and treatment of minor heart anomalies, congenital and acquired defects of the valvular apparatus of the heart.

Morphological, histochemical and histological study of the ileum in the Iraqi Black Partridge (Francolinus francolinus)

Objective: This project aimed to study the morphological description and histological structure of ileum in Iraqi black partridge (Francolinus francolinus). Methods: To conduct this investigation, 20 healthy Iraqi black partridge were collected from local suppliers. Birds were euthanized, dissected and then specimens were processed for histological and histochemical staining techniques. Results: A morphological study showed that the ileum appears as a short narrow tubular structure. It extends from the wide end of the jejunum and ends in the Ileo-caecal junction region. Histologically, the wall ileum consists of four tunica mucosa, submucosa, muscularis and serosa. The mucosa was lined by simple columnar epithelium with goblet cells. The muscularis mucosa is arranged in two thick layers of smooth muscle fibers, outer longitudinal and inner circular bundles. The tunica submucosa was a thin layer of fibrous connective tissue. Tunica serosa was loose connective tissue covered by mesothelium. The goblet cells gave a positive reaction with PAS stain. Conclusion: Goblet cells neutral mucopolysaccharide secretions; in fact, the latter stain is an indicator mucin substance which are very important in digestion and absorption and subsequent body growth of the bird.

Zoning inside the renal fascia: The anatomical relationship between the urinary system and perirenal fat

ObjectivesTo examine the anatomical relationship between the urinary system and perirenal fat, and to clarify the zoning inside the renal fascia.MethodsUsing computed tomography images from 50 men, we examined perinephric veins to reveal vessel communication in perirenal fat. Nine cadavers were dissected to investigate connective tissue continuity and vessel communication inside the renal fascia. Eight retroperitoneal specimens were macroscopically observed: four from the anterior and four from the posterior aspects. One specimen was used to obtain retroperitoneal transverse sections to study macroscopic anatomy and histology.ResultsPerinephric veins were classified into four types (superior, middle, inferior and lateral) using computed tomography. Most of the inferior perinephric veins were connected to the ipsilateral gonadal vein. In the cadaveric study, the superior and middle perinephric veins communicated with veins deriving from the ipsilateral adrenal gland. A fibrous connective tissue gap between perirenal fat and renal hilar fat was observed in posterior aspect dissection. From the gap, we could dissect the urinary system from perirenal fat en bloc along with a thin fibrous connective tissue layer. Communicating vessels between perirenal fat and the urinary system were rare.ConclusionsOur results suggest that perirenal fat belongs to the connective tissue of the gonad and the adrenal gland. The urinary system is separate from perirenal fat, and is located on the dorsal side inside the renal fascia. This concept of zoning inside the renal fascia is valuable particularly in retroperitoneoscopic donor nephrectomy.

Gross and histopathological alterations associated with cystic echinococcosis in small ruminants.

Hydatidosis, an important parasitic zoonoses is a major public health as well as economic concern throughout the world. A total of 2100, sheep (2052) and goats (48), slaughtered or spontaneously dead, from various areas of Kashmir valley were screened for the presence of hydatidosis. Out of 2100 cases, 85 were positive for hydatidosis. The frequently infected organs were lungs and liver. The liver was observed to be the most frequently infected organ with relative prevalence of 61.17% followed by lungs (38.82%). The pulmonary cysts were more fertile (55%) compared to hepatic cysts (45%). Histopathologicallly, the cyst wall consisted of the inner germinal, middle lamellated/laminated, and outer fibrous layer. Inflammatory reaction around the cyst was variable and was characterized by an inner zone of loosely arranged fibroblasts infiltrated with mononuclear cells, followed by densely arranged fibroblasts along with mononuclear cells; and an outer layer of fibrous connective tissue. Fibroplasia and calcification were noted at places. In liver besides the cellular reaction against the expanding cyst, hepatocellular degeneration and cirrhosis were observed, the severity of which was inversely related to the distance from the cyst. The structural details of the protoscolices were clearly discernable.

Liver of the fish Gymnotus inaequilabiatus and nematode larvae infection: Histochemical features and expression of proliferative cell nuclear antigen.

Histopathological lesions due to third-larval stage of nematode Brevimulticaecum sp. within the liver of a subpopulation of 31 Gymnotus inaequilabiatus from the Pantanal Region (Brazil) were studied with histochemical and immunohistochemical methods. In 93.5% of fish, livers harboured nematode larvae and the intensity of infection ranged from 8 to 293. In livers with highest number of larvae, the hepatic tissue was occupied primarily by the nematodes. Each larva was encircled by focal inflammatory granulomatous reaction. Within the thickness of the granuloma, three concentric layers were recognized: an inner layer of densely packed epithelioid cells, a middle layer of mast cells (MCs) entrapped in a thin fibroblast-connective mesh and an outer layer of fibrous connective tissue with fibroblasts. Epithelioid cells and fibroblasts within the thickness of the granuloma wall were positive for proliferative cell nuclear antigen (PCNA). Moreover, several hepatocytes in infected liver were immunoreactive to PCNA. Occurrence of rodlet cells and MCs in parenchyma, in close proximity to the encysted nematode larvae and near the blood vessel of infected liver, was observed. Macrophage aggregates (MAs) were numerous within the granulomas and scattered in parenchyma of the infected liver. High quantity of haemosiderin was encountered in MAs and hepatocytes of infected liver.

Nematode infection in liver of the fish Gymnotus inaequilabiatus (Gymnotiformes: Gymnotidae) from the Pantanal Region in Brazil: pathobiology and inflammatory response.

BackgroundA survey on endoparasitic helminths from freshwater fishes in the Pantanal Region (Mato Grosso do Sul, Brazil) revealed the occurrence of third-larval stage of the nematode Brevimulticaecum sp. (Heterocheilidae) in most organs of Gymnotus inaequilabiatus (Gymnotidae) also known by the local name tuvira. The aim of the present study was to examine Brevimulticaecum sp.-infected tuvira liver at the ultrastructural level and clarify the nature of granulomas and the cellular elements involved in the immune response to nematode larvae.MethodsThirty-eight adult specimens of tuvira from Porto Morrinho, were acquired in January and March 2016. Infected and uninfected liver tissues were fixed and prepared for histological and ultrastructure investigations.ResultsThe prevalence of infection of tuvira liver by the nematode larvae was 95 %, with an intensity of infection ranging from 4 to 343 larvae (mean ± SD: 55.31 ± 73.94 larvae per liver). In livers with high numbers of nematode larvae, almost entire hepatic tissue was occupied by the parasites. Hepatocytes showed slight to mild degenerative changes and accumulation of pigments. Parasite larvae were surrounded by round to oval granulomas, the result of focal host tissue response to the infection. Each granuloma was typically formed by three concentric layers: an outer layer of fibrous connective tissue with thin elongated fibroblasts; a middle layer of mast cells entrapped in a thin fibroblast-connective mesh; and an inner layer of densely packed epithelioid cells, displaying numerous desmosomes between each other. Numerous macrophage aggregates occurred in the granulomas and in the parenchyma.ConclusionsOur results in tuvira showed that the larvae were efficiently sequestered within the granulomas, most of the inflammatory components were confined within the thickness of the granuloma, and the parenchyma was relatively free of immune cells and without fibrosis. Presumably this focal encapsulation of the parasites permits uninfected portions of liver to maintain its functions and allows the survival of the host.

Ultrastructural Assessment of Granulomas in the Liver of Perch (Perca fluviatilis) Infected by Tapeworm

Granulomas caused by migration of larvae of a helminth parasite, Triaenophorus nodulosus, within the liver of perch (Perca fluviatilis) from Rimov Dam Lake (Czech Republic) were assessed by transmission electron microscopy. Lesions were found in the liver of 29 out of 34 perch examined (85.2%) and there were between 1 and 15 T. nodulosus larvae identified per host. Pathological changes were more severe in livers containing more granulomas. Within the granulomas, there were three concentric regions: an outer layer of fibrous connective tissue, a middle clear epithelioid layer and a central dark spindle cell layer. The outer layer contained mast cells, fibroblasts, thick collagen bundles and epithelioid cells. The granulomas contained few lymphocytes and macrophages. Hepatocytes adjacent to the granulomas showed pronounced degeneration (ranging from vacuolar degeneration to acute cellular swelling).

上顎洞に進展したchronic expanding hematoma の1例

Chronic expanding hematoma （CEH） is a lesion that develops gradually after trauma or surgery. Generally, it arises in the pleural cavity, lower leg, abdomen, or backj occurrence in the head and neck region is uncommon.We report a case of CEH arising in the maxillary sinus of a 47-year-old man who was referred to our hospital for further evaluation of a lesion in the left maxillary sinus. No subjective symptoms were reported at presentation, and he had no remarkable family or past medical history. Panoramic X-ray films showed a radiopaque domeshaped mass in the left maxillary sinus, and computed tomographl demonstrated a well-circumscribed round lesion. The lesion, which was clinically diagnosed as a maxillary tumor, was resected under general anesthesia. Histopathological examination revealed that the tumor consisted of an inner layer of hematoma with capillaries, a middle layer of granulation tissue, and an outer layer of dense fibrous connective tissue with calcification. The histopathological diagnosis of the lesion was CEH. There was no sign of recurrence 19 months after the operation.

Comparison of Biomaterial Implants in the Dental Socket: Histological Analysis in Dogs

Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For this reason, many researchers have evaluated the bone substitutes. The present study evaluated soft and hard tissue reactions to two different hydroxyapatites HAs (synthetic HA and natural HA) and bioactive glass implanted into the sockets immediately after extraction. First and third upper and lower premolars, on both sides, were extracted from six female dogs. The alveolar sockets were randomly assigned to four groups: Group 1 - control (unfilled), Group 2 - filled with synthetic hydroxyapatite, Group 3 - filled with bovine bone mineral (natural HA), and Group 4 - filled with bioactive glass. The animals were euthanized at 4 weeks (n = 2), 8 weeks (n = 2), and 28 weeks (n = 2) after extraction. The mandible and maxilla of each animal were removed for histological analysis to determine soft tissue reactions, newly formed bone, bone characteristics, and presence or absence of implanted materials. Most particles of synthetic hydroxyapatite had bone formation on their surface, although some particles showed a layer of fibrous connective tissue. The bovine bone mineral group exhibited particles partially replaced with bone formation. The bioactive glass group showed particles with a thin layer of calcified tissue, but was absent in some specimens, suggesting complete resorption. All biomaterials had similar behavior. Bovine bone mineral, compared to synthetic hydroxyapatite and bioactive glass, showed a larger number of particles covered with osseous tissue. All biomaterials interfered with the socket repair process.

Cemento-ossifying fibroma of mandible: A case report

Cemento Ossifying fîbroma is a benign fîbro-osseous lésion that arises from the periodontal membrane. The periodontal membrane is a layer of fibrous connective tissue surrounding the roots of teeth. It contains multipotential cells that are capable of forming cementum, lamellar bone, and fibrous tissue. These tumours occur in the third and fourth decades of life, with prédilection for women. The mandible is more commonly involved than the maxilla. This article describes a case of Cemento-ossifying fîbroma in a 45-year-old female patient. A histopathological diagnosis of Cemento ossifying fîbroma was made. An accurate diagnosis requires careful clinical, radiological and histological corrélation in order to make an optimal treatment and an excellent outcome.

１０年前にクリップされた破裂脳動脈瘤の病理学的所見とその臨床的意義

A 74-year-old man presented with subarachnoid hemorrhage (SAH) and underwent neck clipping of a left middle cerebral artery (MCA) aneurysm 10 years ago. This patient presented with SAH again due to rupture of a de novo aneurysm of the anterior communicating artery (A-com. aneurysm). The A-com. aneurysm was clipped successfully. The “old” left MCA aneurysm was then inspected. A collapsed “old” aneurysmal dome and a previously applied clip were identified. The “old” aneurysmal dome was resected for histopathological examination. The wall of this aneurysmal dome varied in thickness and consisted of a thin layer of fibrous connective tissue. Fibroblasts were scattered in the aneurysmal wall and either the muscular layer or internal elastic lamina was absent. The aneurysmal dome collapsed to a certain degree, but the lumen of the dome was completely intact. In addition, neovascularization of microcapillaries was observed both inside and outside the aneurysmal dome. Some of these microcapillaries were filled with fresh erythrocytes. Thus the aneurysmal wall was apparently “vigorous.” The previous orifice of the aneurysm did not fuse together at all and could be opened widely with ease during preparation for histopathologic examination. We speculated that the clipped aneurysmal dome survived for 10 years for the following reasons: 1) Although the mechanism of neovascularization of the microcapillaries is unclear, the clipped aneurysmal dome may have obtained nourishment from the microcapillaries. 2) The cerebrospinal fluid may have incubated the dome and provided optimal circumstances for its survival. Considering the radical cure for ruptured cerebral aneurysms by neck clipping or coil embolization, the findings described in this report will be valuable for neurosurgeons and neurointerventionists. Regardless of the time since treatment, ruptured aneurysms treated by either neck clipping and/or coil embolization are at risk of recurrent subarachnoid hemorrhage when the blood re-enters the aneurysms in cases such as clip slip-off or coil compaction.

Experimental replacement of thoracic esophageal segment with a biomaterial artificial esophagus in dogs

Objective To implant 80 mm-long artificial esophagi constructed of biomaterial in dogs, observe the perioperative survival rates and the incidence of postoperative complications, and study the mechanisms of postoperative healing. Methods Specimens of the implanted esophagus, the “neo-esophagi”, were taken for histopathologic study 1, 3, 6, 12, 24 months after operation. Results The incidence of anastomotic leakage after the artificial esophagus implantation was 3.33%. The perioperative survival rate was 96.67%. The incidence of postoperative stenosis in the “neo-esophagi” was 81.48%; the stenoses were treated by expanding with esophagoscopy and implanting a stent. Epithelization of the mucosa in the “neo-esophagi” was completed in 3 to 6 months after surgery. Structures such as submucosal muscle layers, mucous glands, nerve fibers, capillaries, etc. were regenerated after 12 months, and then reconstruction of the fibrous connective tissue layer was completed. Conclusion Implanting a biomaterial artificial esophagus accomplishes safe reconstruction of defects in the esophagus. Advanced cellular structure of “neo-esophagus” can be regenerated after 1 year. Postoperative stenosis, which is related to hyperplasia and retraction of scar tissue, is still the most common complications which limiting the clinical application of the artificial esophagus.

Prevalence and MRI-Anatomic Correlation of Bone Cysts in Osteoarthritic Knees

The objectives of this study were to determine the prevalence of cysts in the weight-bearing areas and interspinous bone cysts in tibial plateau specimens derived from knees with advanced osteoarthritis, to perform MRI-anatomic correlation of these cysts, and to define their histologic characteristics. Forty-two tibial plateau specimens were recovered from patients undergoing total knee replacement surgery for severe osteoarthritis (14 men and 28 women; mean age, 74 years; age range, 58-87 years). The tibial specimens underwent MRI with T1- and T2-weighted MR sequences. No radiographic data were available before MRI. Tibial specimens were sectioned using a high-speed rotating diamond disk into 3-mm-thick slices. MR images and anatomic specimens were analyzed for the presence of cysts in the interspinous and weight-bearing areas. Histologic staining methods included routine Harris hematoxylin stain, trichrome stain, and Alcian blue-PAS stain. Twenty-three (54%) of 42 specimens contained one or more cystic areas, with a total of 30 cystic areas. The cysts were distributed in the weight-bearing area (14/30) and interspinous area (16/30). All cysts seen on the anatomic slices could also be depicted on both MRI sequences. Histologic findings were identical for all noncommunicating cysts and revealed necrotic bone fragments with dead denuclearized cells. The cavities were surrounded by a layer of fibrous connective tissue containing adipocytes and osteoblasts. No evidence of epithelial components was found in the lining of the cavities. Interspinous and weight-bearing tibial cysts are common in severe knee osteoarthritis. The cysts contain necrotic bone fragments and are lined by a nonepithelial fibrous wall. Our findings support the hypothesis that interspinous cysts could result from repetitive bone stresses through the cruciate ligaments. Our findings do not support the use of the term "herniation cyst."

Bone response to three different chemical compositions of fluorcanasite glass‐ceramic

The aim of this study was to evaluate the bone response to three fluorcanasite glass-ceramic compositions with different solubilities (K3, K5, and K8) after implantation in a femur rabbit model. Fluorcanasite glass-ceramic rods were implanted bilaterally in the mid-shafts rabbit femurs. Implants were harvested at 8 and 12 weeks and prepared for histological and histomorphometric analyses at the light microscope level. Bioglass 45S5 rods were used as a control material. At 8 weeks, all fluorcanasite glass-ceramics were entirely surrounded by a nonmineralized connective tissue. At 12 weeks, reduced areas of bone tissue were observed in the cortical area in direct contact with the K3 and K5 fluorcanasite glass-ceramics compared to Bioglass 45S5, whereas no bone tissue was observed in direct contact with the K8 surface. Bone-to-implant contact in the cortical area was affected by the material chemical composition and ranked as follows: Bioglass 45S5>K3>K5>K8 (p=0.001). In the bone marrow, a layer of fibrous connective tissue formed in direct contact with the fluorcanasite glass-ceramics and Bioglass 45S5, and only rarely exhibited contact osteogenesis. All the fluorcanasite glass-ceramics appeared to degrade in the biological environment. The solubility ratio did not alter significantly the biological reply of the fluorcanasite glass-ceramics in vivo. Further modifications of the chemical composition of the fluorcanasite glass-ceramic are required to increase the stability of the material in vivo.

Benign pulmonary epithelial inclusions within the pleura: a case report

BackgroundThe normal visceral and parietal pleura are composed of a mesothelium-lined layer of fibrous connective tissue, consisting predominantly of collagen and elastin fibers, with interspersed nerves, lymphatics, and blood vessels. There is no normal epithelial component to the pleura, and the histologic finding of epithelial cells within pleural tissue typically indicates the presence of a malignant process. The one documented exception to this rule is the occasional occurrence of endometriotic implants, which can result in cyclic thoracic symptomatology and occasionally even hemothorax.Case PresentationWe present a case of seemingly benign epithelial inclusions within the pleura of a sixty year-old male patient who underwent exploratory thoracotomy and subsequent resection of bullous emphysematous blebs. Examination of the surgical specimen revealed well-defined nests of benign-appearing epithelial cells in glandular configurations at multiple sites within the pleura. These cells were immunopositive for TTF-1 and CK7 and immunonegative for calretenin, CK20, and CEA, indicating pulmonary epithelial derivation. Six months after resection, the patient is in stable health, with no clinical or radiologic evidence of bronchogenic carcinoma.ConclusionTo our knowledge, this is the first report of benign pulmonary epithelial inclusions within pleural tissue. It is important to be aware that benign pleural inclusions occur, so as to avoid confusion with more serious processes in a population of patients who may have oncologic risk factors.

Anatomy of the male reproductive system and sperm morphology in the caterpillar‐hunting wasp Ancistrocerus antilope (Hymenoptera, Vespidae)

Abstract. The male reproductive system of the caterpillar‐hunting wasp Ancistrocerus antilope was composed of the testes, seminal vesicles, accessory glands, the penis, and the connecting ducts. The testes, which were paired structures lined with a thin layer of squamous epithelium, were composed of several lobes that contain developing spermatozoa. These spermatozoa began as spermatocytes in the distal portion of the testicular lobe and, as they matured, they moved proximally toward the seminal vesicles. Upon maturation, the spermatozoa were long, thin structures with a nucleus of ∼10–15 μm in length and 1–2 μm in width. Their tails, which were not morphologically distinct from their heads at the gross level, averaged 388±25 μm in length. Once the spermatozoa had fully developed, they traveled from the testes to the seminal vesicles, where they were stored. The walls of the seminal vesicles were composed of a ciliated, pseudostratified, columnar epithelium. A layer of fibrous connective tissue termed the testicular capsule encapsulated both the testes and the seminal vesicles. Upon ejaculation, the spermatozoa moved through the deferent ducts, where they combined with granular fluid from the accessory glands. From here, they traveled via the ejaculatory duct to the penis, where they were expelled. In this study, these anatomical descriptions are discussed in reference to other species of the Hymenoptera.

General morphology of the oral cavity of the Nile crocodile, <i>Crocodylus niloticus</i> (Laurenti, 1768). II. The tongue

The heads of nine 2.5 to 3-year-old Nile crocodiles (Crocodylus niloticus) were obtained from a commercial farm where crocodiles are raised for their skins and meat. The animals from which these specimens were obtained appeared clinically healthy at the time they were slaughtered. A description of the macroscopic and microscopic features of the tongue of the Nile crocodile is presented and the results are compared with published information on this species and other Crocodylia. The histological features are supplemented by information supplied by scanning electron microscopy. Macroscopic features of interest were the dome shaped structures grouped in a triangular formation on the posterior two-thirds of the dorsum of the tongue. These structures were identified by light microscopy to contain well-developed branched, coiled tubular glands and associated lymphoid tissue. Other histological features included a lightly keratinised stratified squamous surface epithelium supported by a thick layer of irregular dense fibrous connective tissue. Deep to this region was a clearly demarcated adipose tissue core with a dense mass of striated lingual musculature. Localised thickenings were present in the epithelium which were associated with ellipsoid intra-epithelial structures resembling taste buds.

Tissue response to poly‐L‐lactide acid‐polyglycolic acid absorbable screws in autogenous bone grafts: a histologic morphological analysis

To evaluate the local bone condition of autogenous chin grafts in contact with resorbable polymers fixation devices. Seven patients presenting severe maxillary and mandibular atrophy underwent alveolar ridge reconstruction with autogenous chin grafts fixed with conventional metallic screws, who received poly L-lactide acid-polyglycolic acid and titanium test screws for histological evaluation after 4 months of implantation. Viable bone tissue could be seen in the specimens related to titanium test screws, with no signs of bone resorption or inflammation. A thick layer of fibrous connective tissue was observed between the resorbable test screws and bone tissue, which presented a few areas of resorption. There are no contraindications of both materials for use as fixation devices in autogenous bone grafts. However, care must be taken when using absorbable screws in a period of 4 months, which can interfere with the sequence of the treatment with endosseous dental implants.

Long-term effects of polyacrylamide hydrogel on human breast tissue.

Polyacrylamide hydrogel is an atoxic, stable, nonresorbable sterile watery gel consisting of approximately 2.5% cross-linked polyacrylamide and nonpyrogenic water. Polyacrylamide hydrogel is widely used in ophthalmic operations, drug treatment, food packaging products, and water purification. In the former Soviet Union, polyacrylamide hydrogel has been used in plastic and aesthetic surgery for more than 10 years, and Kiev City Hospital treats approximately 300 women a year for breast augmentation using the polyacrylamide hydrogel Interfall (Contura SA, Montreux, Switzerland). Capsule shrinkage following these injections has never been observed. The authors examined breast tissue samples from a total of 27 women who had polyacrylamide hydrogel injected at Kiev City Hospital up to 8 years and 10 months earlier. Age at operation, duration of polyacrylamide hydrogel implantation, history of possible side effects to the gel injection, other intercurrent diseases, the reason for present open breast operation, and breast palpation findings before operation were in each case compared with the histological findings on samples taken from breast tissue bordering the gel. The gel presented itself as a dark violet, homogenous mass with a rounded or ragged outline in large or medium-size deposits and as elongated strands, which mimicked the extracellular matrix, in small deposits. Histological findings of the breast tissue bordering the gel showed three different patterns: large collections of gel gave rise to a thick, soft-looking cellular membrane of macrophages and foreign-body giant cells; medium-size deposits were surrounded by just a thin layer of macrophages; and small deposits were not associated with any reaction in the surrounding tissue. Projections of the cellular soft membrane, known as granulomas, were seen in six patients. The granulomas were composed of macrophages, foreign-body giant cells, lymphocytes, and blood cells. A thin layer of fibrous connective tissue was occasionally present around the foreign-body membrane, but the thick fibrous capsule, which has been described in connection with silicone implants, was completely absent. The gel changes could be correlated to neither time since gel injection nor a history of recent injury or inflammation. It is concluded that the polyacrylamide hydrogel Interfall, which has been used in the former Soviet Union, is stable over time, nondegradable, confined to the breast, and diffusion and migration resistant. When the hydrogel is injected in medium-size or large quantities a cellular foreign-body reaction occurs, but in small amounts it is capable of splitting up individual connective tissue fibers and fat cells, substituting for the extracellular connective tissue matrix without eliciting any foreign-body reaction. As far as these data are concerned, polyacrylamide hydrogel is well tolerated by the breast and does not give rise to severe fibrosis, pain, or capsule shrinkage. However, to determine safety with more certainty, a larger sample size would be necessary.