Severe Tissue Necrosis Research Articles

Arachidonic and Linoleic Acids Elicit Isoflavonoid Phytoalexin Accumulation in Phaseolus vulgaris (French bean)

AbstractArachidonic and linoleic, but not α‐linolenic or γ‐linolenic acids, induced necrosis and the accumulation of isoflavonoid phytoalexins in leaves of French bean (Phaseolus vulgaris L.) cv. ‘Red Mexican'. The levels of phytoalexins which accumulated were similar to those found in an incompatible interaction between cv. ‘Red Mexican’and an avirulent race 1 isolate of Pseudomonas syringae pv. phaseolicola. Maximum amounts of phytoalexins accumulated in response to 1.6 mM fattyacids, as opposed to 3.3 or 0.6 mM. The most severe tissue necrosis was not accompanied by the highest levels of phytoalexin accumulation. In contrast to leaves, only trace amounts of phytoalexins were elicited in hypocotyls. The possible significance of, these results is discussed in terms of mechanisms leading to plant cell death and phytoalexin accumulation.

Measure of Tissue Resistivity in Experimental Electrical Burns

Studies were conducted in 14 mongrel dogs to compare resistivities in normal muscle with those from muscle subjected to electrical burns. One-ampere, 60-Hz currents were passed between the hind limbs of the dogs producing injury in three measurement regions of the gracilis muscle. Histology, heart rate, body temperature, arterial and pulmonary artery pressure, cardiac output, hematocrit, leukocyte counts, fibrinogen levels, and platelet levels were determined. Muscle resistivity associated with severe tissue necrosis was 70% lower than control values. Resistivity in tissue showing edema and minimal necrosis decreased 20 to 40% from control values. Muscle showing only edema had a 10 to 30% decrease in resistivity.

Measure of tissue resistivity in experimental electrical burns.

Studies were conducted in 14 mongrel dogs to compare resistivities in normal muscle with those from muscle subjected to electrical burns. One-ampere, 60-Hz currents were passed between the hind limbs of the dogs producing injury in three measurement regions of the gracilis muscle. Histology, heart rate, body temperature, arterial and pulmonary artery pressure, cardiac output, hematocrit, leukocyte counts, fibrinogen levels, and platelet levels were determined. Muscle resistivity associated with severe tissue necrosis was 70% lower than control values. Resistivity in tissue showing edema and minimal necrosis decreased 20 to 40% from control values. Muscle showing only edema had a 10 to 30% decrease in resistivity.

Carcinoma of the base of the tongue: results of radical irradiation with surgery reserved for irradiation failure.

Between 1964 and 1977, 95 previously untreated patients with squamous cell carcinoma of the base of the tongue received treatment with curative intent at the University of Florida. Eighty-six of the 95 patients (91%) had Stage III or IV disease at presentation. Eighty-nine patients received radical courses of irradiation to the primary with or without neck dissection(s), with surgery reserved for salvage of irradiation failure. Six patients underwent planned combined treatment of the primary lesion. Of the 89 patients whose primary lesions were radically irradiated, failure at the primary site occurred in 24% of those with T1-3 lesions and 78% with T4 lesions. Control results were related to irradiation treatment technique. None of the 9 patients with Stage I-II disease died of the cancer. Actuarial survival at 5 years for Stage III patients was 46%. Within the Stage IV population there is a subgroup of patients with highly treatable and curable disease. The addition of a neck dissection following irradiation of N2-N3 neck disease decreased the incidence of failure in the neck. No patient developed severe soft tissue necrosis or required mandibulectomy for bone exposure following irradiation.

Regeneration of submandibular salivary gland autografted in the rat tongue.

Autologous SMG fragments were implanted in tongues of male rats which were sacrificed 15-20 min, 24 hr, 72 hr, 1 week, or 8 weeks after implantation. The tongues were excised, fixed, and processed for light and electron microscopy. In addition, some rats were injected with [3H]-thymidine 1 hr before sacrifice and the labeling indices (L.I.) of the salivary epithelial and interstitial cells were calculated. Twenty-four hours after implantation, SMG autografts showed massive central necrosis with some acini and ducts surviving at the periphery of the lobules. There was marked infiltration of the autografts with neutrophils and macrophages. Also the basal laminae surrounding the necrotic acini and ducts remained intact. The morphology of the autografts after 72 hr was similar to that after 24 hr except that there was additional necrosis and acini and ducts could no longer be identified in the autografts. By 1 week after implantation, the autografts showed lobular morphogenesis, ductal branching, and revascularization. At this time, the regenerating salivary epithelium appeared undifferentiated with no evidence of secretory granules. The L.I. of interstitial and ductlike structures showed significant increases over control values at 1 week after implantation, and then declined toward control levels by 3 weeks after implantation. By 8 weeks after implantation, there was evidence of acinar and striated ductal cytodifferentiation in two autografts. The results emphasize the potential of SMG autografts to regenerate subsequent to severe tissue necrosis.

Reactions of the dental pulp to microbial provocation of calcium hydroxide treated dentin.

The purpose of the present study was to determine whether treatment of dentin with calcium hydroxide reduces pulp irritation caused by microbial products. The experiment was carried out in three young monkeys. Cavities were prepared on the buccal tooth surface deep into dentin of 62 teeth. Calcium hydroxyde mixed with distilled water was placed in one group of cavities. A set of control cavities received treatment with saline soaked filter-paper discs. The calcium hydroxide dressing and the saline discs were separated from the oral cavity for a period of 14 or 60 d by a Teflon disc and a layer of zinc oxide-eugenol cement. At the end of these periods the content of each cavity was removed and substituted by lyophilized material from cultivated plaque bacteria. After 3 d of exposure the monkeys were killed and the teeth subjected to histologic treatment. Assessments made in the light microscope revealed that pulps subjacent to calcium hydroxide-treated dentin in the majority of cases showed no or only slight infiltrates of inflammatory cells. In controls, 13 out of 22 pulps showed severe inflammatory cell infiltrates or total pulp tissue necrosis. It was concluded that treatment of dentin with calcium hydroxide may reduce the possibility for bacterial components to cause pulp tissue damage.

Extensive local necrosis following the intravenous use of X-ray contrast medium in the upper extremity

Local complications after the intravenous introduction of contrast media, though rare, are well recognized. Most of the reported cases of local soft tissue necrosis are related to leg phlebography. There is little information in the medical literature concerning the occurrence of such complications inthe upper extremity. Here, a case of severe soft tissue necrosis resulting from an intravenous injection of Conray 325* in the hand is presented. A girl of 6½ years was admitted into the Paediatric Unit of the Princess Margaret Hospital, Hong Kong because of acute nephritic syndrome which was later shown to be due to disseminated Lupus erythematosis. Steroid treatment was started in order to arrest its rapid progress. In order to outline the kidneys for renal biopsy, 20 c.c. of Conray 325 were injected into a vein over the dorsum of the girl's right hand, using a 21 -gauge metal scalp-vein needle.

Clinical aspects of anaerobic infection

Summary This paper is a review of clinical aspects of anaerobic infections considered in the light of current anaerobic cultural techniques. Three themes recur from clinical observations, first, that certain conditions predispose to anaerobic suppuration—compromised blood supply, tissue destruction or antecedent infection with aerobic bacteria or viruses. These conditions produce low oxidation-reduction potential (Eh) favourable for growth of anaerobes. Second, that anaerobes are secondary invaders in which the inaugural event is spread of normal flora beyond the confines of mucocutaneous barriers. The third observation is that at the infected site there is, in many anaerobic infections, a complex bacteriological flora. The classical idea of, ‘one organism, one disease’ is no longer tenable in these situations. Clinical clues to the possible presence of anaerobes as a cause of infection include, site of infection (on or close to mucosal surfaces), presence of foul-smelling discharge, severe tissue necrosis, gas in tissues, failure to culture aerobes where sepsis is obvious, and failure of chemotherapy when drugs inactive against anaerobes are used. Anaerobic infections in the head and neck, chest, abdominal cavity, female pelvis and soft tissues are described in detail, relating clinical features, site of- infection and bacterial pathogens—emphasising the role of anaerobes.

ADRIAMYCIN EXTRAVASATION

Adriamycin extravasation creates a severe tissue necrosis which is unusual, because it may not appear until several weeks later, and may continue to worsen for several months. As soon as the progressive nature of the tissue necrosis is established, we recommend that an early wide excision be performed in an attempt to remove the necrotic area and the surrounding tissues containing the extravasated drugs--before it has had an opportunity to diffuse even further. Adequate debridement requires removal of any adjacent tissue that is indurated, reddened, edematous, or pale. Skin grafts take poorly if there are small amounts of Adriamycin left in the tissue of the recipient site. Synergistic effects with radiotherapy, and continued systemic Adriamycin therapy, can aggravate or recall necrosis. The administration of more dilute solutions of Adriamycin may decrease the hazard of extravasation necrosis.

An experimental investigation of tissue changes associated with dermal and mucosal contact of epoxy resins and their curing agents

In an investigation of the skin and mucosa of rabbits and dogs to study the effect of contact with non-polymerized and polymerized epoxy resins and with their curing agents (diethylenetriamine), severe tissue changes and necrosis were observed. The lesions were not due to the resin but to the curing agent. The non-polymerized epoxy resin produced a thickening of the keratinized layer of the epithelium.