Connective Tissue Necrosis Research Articles

Incidence of multiple bacterial infections in Pacific whiteleg shrimp, Litopenaeus vannamei

A rare incidence of multiple bacterial infections was reported in Litopenaeus vannamei grow-out ponds in India. The pathogenic organisms identified are Aeromonas veronii, Bacillus flexus, Kurthia gibsonii, Shewanella decolorationis, Bacillus cereus and Shewanella amazonensis. The infected shrimp showed various clinical and morphological changes such as mucus secretion in the hepatopancreas, bacterial spots in the carapace, red or pink discoloration of abdomen with black stripes and highly melanized body. The Histological studies of the hepatopancreas revealed bacterial plaque in the lumen, inflammatory response, necrosis of connective tissue and lipid droplets. The histology of stomach detected degradation of spongy connective tissue, hypertrophied nucleus and the abdomen showed bacterial plaques in the gaps of the muscle fibre. Histochemically, both gram-positive and gram-negative bacteria's were identified in the hepatopancreas and the presence of mucus in the lumen of hepatopancreatic microtubules was confirmed by Alcian blue staining. The electron microscopic studies of the infected shrimp showed multiple bacterial infections and cellular responses like phagocytosis in the hepatopancreas, using transmission electron microscope and scanning electron microscopic confirmed the presence of bacillus and coccobacillus-shaped bacteria in carapace.

Infective myositis, an uncommon presentation of melioidosis: a case report and review of the literature

BackgroundMelioidosis is considered endemic in certain areas of the world. Musculoskeletal and soft tissue involvement are relatively uncommon presentations in melioidosis. We present a case of infective myositis in a patient with melioidosis in Sri Lanka, which is not considered an endemic country. Even though multiple cases of melioidosis have been reported with an increasing number in Sri Lanka, infective myositis secondary to melioidosis was not reported previously.Case presentationA 60-year-old Sinhalese man with diabetes presented with fever of 4 months’ duration and a limp with a painful lump on the right side of the upper thigh of 2 months’ duration. He had been treated in a local hospital for community-acquired pneumonia 3 weeks prior to this admission, for which he had received intravenous meropenem and teicoplanin with intensive care unit admission. He had a 0.5-cm × 0.5-cm tender lump over the right vastus lateralis muscle, and contrast-enhanced computed tomography of the area showed an ill-defined, heterogeneously enhancing, hypodense area involving the vastus lateralis, vastus intermedius, and quadratus femoris, suggestive of infective myositis but without abscess formation. Histopathology of the muscle biopsied from the vastus lateralis showed suppurative inflammation of subcutaneous fat with connective tissue necrosis and muscle infiltrated by lymphocytes. These features are suggestive of infective myositis possibly due to melioidosis. Although the result of a culture taken from the muscle biopsy was negative, the patient’s antibody titer was strongly positive for melioidosis. He did not show any other areas with infected foci. He was treated with intravenous meropenem for 2 weeks and responded well. He was discharged with trimethoprim-sulfamethoxazole for 6 months as a maintenance therapy.ConclusionMelioidosis is commonly an undiagnosed disease that has a wide variety of clinical presentations. Myositis in melioidosis is uncommon, and careful evaluation is mandatory to avoid misdiagnosis of this treatable but fatal disease. The clinician should have a high index of clinical suspicion, and further clinical and epidemiological studies are needed to determine the true burden of the disease.

Alveolar mucosa necrosis induced by utilisation of calcium hydroxide as root canal dressing

This case demonstrates the ability of calcium hydroxide to cause connective tissue necrosis. A patient with a history of trauma exhibited a large area of external inflammatory root resorption affecting the cervical and middle thirds of tooth 12. After root canal cleaning, a calcium hydroxide root canal dressing was applied to control the resorption process. After three days when the patient attended for replacement of the dressing an irregular zone of necrosis was observed on the buccal aspect of the alveolar mucosa. Careful curettage and irrigation was then performed to remove the extruded calcium hydroxide and necrotic tissue. After curettage, the root canal was accessed and irrigated with saline solution for removal of remnants of the dressing. The dressing was than replaced taking care to avoid contact with soft tissue, which might induce further damage, minimising the overflow of material. Improvement in healing was observed at 15-day follow-up, with complete closure of the lesion by soft tissue. At the 120-day follow-up, no scar was detected. At 180-day follow-up, the root canal was filled only with mineral trioxide aggregate (MTA) with aid of K files #20 and #50. At two-year follow-up, there were no symptoms and the resorption process seemed to have ceased. It is important to emphasise the damage that may occur when calcium hydroxide is in close and extended contact with the soft tissues, which could happen when dressing material is extruded through a root resorption.

HISTOPATHOLOGY OF MODIOLUS BARBATUS

Infection of Gymnophallus sp. in the bearded horse mussel (Modiolus barbatus) was studied in samples collected during 1 year in the Mali Ston Bay (eastern Adriatic Sea). Mean prevalence of sporocyst was low (3.5%), which peaked in February (7.1%), whereas the mean metacercariae prevalence was 8.1%, peaking in September (16.7%). Histologically the Gymnophallus sp. sporocyst infection in bearded horse mussel resulted in clear reaction of bivalve tissue, where the induced changes depend strongly on the site of trematode infection. Retardation of gametogenesis, necrosis of connective tissue and hemocytic infiltration are the main histological features of infection in this new host.

Synergistic necrotizing cellulitis as a complication of peritonsillar abscess

Peritonsillar abscess, a complication of tonsillitis, is not uncommon. The usual treatment consists of needle aspiration or surgical drainage and antibiotic treatment. Tonsillectomy may be used in the management of this condition, either at the time of diagnosis or after an interval period. Severe complications of peritonsillar abscess are rare. Synergistic necrotizing cellulitis is a fulminant infection associated with spread along fascial plains, necrosis of connective tissue and muscle, and high mortality. It is usually otondogenic in origin in the cervicofacial area and occurs in debilitated or immune compromised patients. We discuss cervicofacial-necrotizing soft tissue disease and report an unusual case of extensive synergistic necrotizing cellulitis of the neck, chest, and shoulder as a result of a peritonsillar abscess. (Am J Otolaryngol 2001;22:415-419. Copyright © 2001 by W.B. Saunders Company)

Zum histochemischen und färberischen Verhalten des Koriums bei der Solardermatitis des Rindes

Early changes in photodynamic dermatitis of a 12-year-old black-spotted cow (Holstein cross) were characterized by splitting of collagen fibers and loss of acid mucopolysaccharides which were believed to be the result of a process of disaggregation and depolymerization. The resorcin- and fuchsinophilic material in the chronically inflammed corium was shown histochemically to be a mucoprotein similar to the cement substance in pathologically altered elastic fibers. Necrosis of connective tissue and a defective but increased synthesis of fibers were considered responsible for the production of this material. Finally, the comparative pathological aspects of this “elastotic” degeneration of connective tissue were discussed.

Reactions of Connective Tissues After Protracted Fractionated Irradiation of Laryngeal Carcinoma

With increasing experience in protracted fractionated irradiation, it has been thought that one of the advantages of this method is that the connective stroma remains functionally and also morphologically almost unaltered, and that this is responsible to a large extent for the improved radiation effects. Clinical observations, however, of the fibrin reaction of the mucous membrane in the early stages of protracted fractionated irradiation, and of the atrophy, sclerosis, edema, and necrosis of connective tissue in later stages, are contradictory to this view. Thus it seems justified to describe microscopic findings on the connective tissue observed in the larynx one to ten months after protracted fractionated irradiation. At the time of fibrinous epithelitis, the connective tissue is definitely altered. Absence or irregularity of nuclear staining, large nuclei, vacuolization of the cytoplasm, and fatty degeneration are exhibited microscopically. In this stage, various amounts of fibrin are present in the subepithelial and deep connective-tissue layers (Fig. 1). The changes are less advanced than those in the epithelial cells, which are completely disintegrated at the time of the fibrinous radiomucositis. One to two months after irradiation, the most frequent change in the connective tissue is a fibrinoid necrosis. This is best demonstrable with Weigert fibrin stains. With ordinary methods of staining, it is not recognizable as such. In some cases, one may later observe transition of areas of fibrinoid necrosis into colliquation, and spotty disintegration of the involved structures. On the other hand, a transformation into hyaline sclerotic scar tissue is often seen. In the latter cases, the entire lamina propria of the larynx becomes atrophic to such an extent that the glands seem to be located immediately below the regenerated epithelium, due to the atrophy of connective layers (Fig. 2). The elastic fibers lie close to each other in such conditions. Necrotic areas of the connective tissue are located chiefly in the internal layer, near the lumen. This suggests that, in addition to the direct effects of radiation, there may be secondary accidents precipitating retrogressive connective-tissue changes. The almost constant finding of fusiform bacilli and of gram-positive cocci in disintegrated connective tissue indicates that secondary infections progressing from the lumen may play an important role in the development of such changes. The boundaries of the necrotic areas often display characteristic retrogressive nuclear changes and also a mild lymphoid cellular reaction. After more intense irradiation, lymphoid cells may be absent, the boundaries of the necrotic areas being marked only by a zone of nuclei in all stages of karyorrhexis, pyknosis, and karyolysis.