Maxillary antral mucocele and its relevance for maxillary sinus augmentation grafting: a case report.

Paranasal sinus mucoceles are benign, locally expansile cyst-like masses that are filled with mucus and lined with epithelium. Most occur in the frontal sinus. Maxillary sinus mucoceles are presumably uncommon in the United States and European countries, although they have been frequently reported in Japan, particularly following Caldwell-Luc surgery. Clinical symptoms may not appear for at least 10 years postoperatively. Chronic sinus inflammation and allergic disease are also common causes of paranasal mucoceles. This paper provides an overview of maxillary sinus mucoceles and presents a case study involving a 62-year-old Latin male whose asymptomatic maxillary sinus mucocele was not revealed until he presented for maxillary sinus grafting and implant placement.

Trauma-induced Kaposi's sarcoma of the hallux. An unusual case.

Kaposi's sarcoma is the most common malignant lesion in patients who test seropositive for the human immunodeficiency virus. Although many cases of this tumor have been described in the literature, only a few cases have been related to Koebner's phenomenon following trauma. Biopsy of lesions remains the standard method of diagnosis, but the numerous treatment options available today require treatment to be determined on a case-by-case basis. The authors present an unusual case of trauma-induced, acquired immunodeficiency syndrome-related Kaposi's sarcoma of the hallux with successful treatment through radiotherapy.

Cutaneous disseminated histoplasmosis in AIDS patients in south Florida.

BACKGROUND: Histoplasma capsulatum is a dimorphic pathogenic fungus endemic to the Mississippi and Ohio river valleys. In the immunocompetent it causes a self-limited disease, but in the immunocompromised may lead to disseminated disease (disseminated histoplasmosis (DH)). It is one of the opportunistic infections which defines the acquired immunodeficiency syndrome (AIDS) and is rarely encountered outside endemic regions. METHODS: Clinical, laboratory, and histologic information concerning seven patients with DH and AIDS in South Florida was recorded. RESULTS: We report seven cases of DH with mucocutaneous lesions in patients infected with the human immunodeficiency virus (HIV). All patients had markedly depressed CD4 counts of less than 40 cells/mm3, and only two had traveled to endemic areas. Two out of the seven patients were diagnosed with HIV/AIDS at the time DH was identified. All of our patients had mucocutaneous lesions at the time of diagnosis, which clinically presented as a generalized papular eruption, ulcers, and erythematous scaly plaques. CONCLUSIONS: Even in non-endemic regions, HIV-positive patients presenting with fever, chills, weight loss, hepatosplenomegaly, anemia, cough, lymphadenopathy, and mucocutaneous lesions should have an early skin biopsy specimen taken for mycologic tissue culture and histopathologic evaluation for disseminated fungal infections.

Primary angiosarcoma of the rib.

A 64-year-old man had a lytic rib lesion that dramatically increased in size in 4 weeks. A bone scan showed a corresponding photopenic focus. Biopsy revealed a malignant tumor with sarcomatous areas suggestive of angiosarcoma. Review of the literature shows that angiosarcoma is rarely seen as a primary rib lesion.

Propane thermal injuries: case report and review of the literature.

"Burn-like" propane thermal injury is produced by evaporative heat loss causing damage to vital structures. Acute appearance is that of heat burn with progressive vascular compromise. Histopathologic study demonstrates epidermal and dermal necrosis followed by vascular thrombosis. Physicians should be aware of this injury and its consequence in light of the widespread use of pressurized propane storage.

Adaptive responses of coronary circulation and myocardium to chronic reduction in perfusion pressure and flow.

We tested the hypothesis that chronic reduction in perfusion pressure and flow in the coronary circulation induces a state of myocardial "hibernation" characterized not only by a steady-state reduction in myocardial O2 consumption (MVO2) but also by evidence of persistent dilator reserve of the distal vasculature. Biochemical and morphological changes in the coronary vasculature were also assessed. Experiments were conducted in swine with an extraluminal coronary stenosis placed 4-32 wk before study. Stenosis reduced lumen diameter by approximately 80% at the time of final experimentation. Baseline, regional myocardial blood flow distal to the stenosis in both endocardial and epicardial layers was reduced vs. that of the normal zone. Vasodilator reserve persisted in both endocardial and epicardial layers of the stenosis zone. Flow increased in each layer in response to adenosine plus phenylephrine and failed to decline despite a marked reduction in perfusion pressure in response to adenosine alone. Regional MVO2 at baseline was reduced vs. historical controls without coronary stenosis. Protein synthesis rate in coronary vessels of the stenosis zone was reduced vs. that of the normal zone. Morphological responses of stenosis zone vessel walls were heterogeneous. Smaller microvessels exhibited mild hypertrophy of their walls, whereas walls of larger microvessels tended to atrophy. Thus chronic reduction in perfusion pressure and flow induces a state of myocardial hibernation characterized by a steady-state reduction in MVO2 in association with persistent dilator capacity. Biochemical and morphological changes occur in microvessel walls and may contribute to observed physiological responses.

A new bioabsorbable intravascular stent: in vitro assessment of hemodynamic and morphometric characteristics.

Currently available intracoronary stents are permanent and their placement may be complicated by thrombosis and restenosis. We have developed a new bioresorbable stent constructed of type I collagen. This stent has a compliant tubular structure that is self expanding and carries a net negative surface charge to increase hemocompatibility. In vitro histologic and morphometric examination was performed by deploying the stent in six pressure fixed explanted porcine arteries. Morphometry revealed a close relationship between the stent external diameter 2.9 +/- 0.4 mm) and the arterial lumen diameter (3.0 +/- 0.4 mm). A relative reduction in arterial lumen diameter secondary to stent placement of 17% to 26% was observed. Folding of the stent wall was noted in those preparations where the stent external diameter was larger than the arterial lumen diameter. Polyvinyl chloride (PVC) tubing was used as a mock arterial segment for flow studies. Flow at baseline and following stent placement was determined at perfusion pressures of 10, 50, and 80 mmHg. A modest reduction in flow following stent placement of between 2% and 6% was observed. Thus, type I collagen may be used to construct a self expanding tubular stent. Morphometric and hemodynamic evaluation reveals a modest impact on arterial lumen dimensions and flow.

Role of endogenous prostacyclin in myocardial blood flow regulation distal to a severe coronary stenosis.

To test the hypothesis that endogenous prostacyclin is required to maintain reduced arteriolar tone distal to a severe coronary arterial stenosis under basal conditions and during challenge with a vasoconstrictor eicosanoid such as thromboxane A2 10 closed chest, domestic swine were prepared with an artificial stenosis, which reduced the luminal diameter of the left anterior descending coronary artery by 80%. Haemodynamic variables, regional myocardial blood flow (microsphere method), and lactate metabolism were measured at control (1); after infusion of U46619 (thromboxane A2 mimetic) distal to the stenosis at 1 microgram.min-1 for 10 min and 5 micrograms.min-1 for 10 min; at control (2); after indomethacin infusion distal to the stenosis; and after repeat infusion of U46619. At the end of the study the animal hearts were removed and their coronary vessels harvested for in vitro determination of prostacyclin (PGI2) production. Regional myocardial blood flow in all layers of the heart distal to the stenosis did not change compared with control during the initial 1 microgram.min-1 dose of U46619 but was reduced significantly after the 5 micrograms.min-1 dose (approximately 20% vs control). Distal zone flow (all layers) returned to baseline at control (2) and remained unchanged after indomethacin infusion. Although distal zone flows were reduced significantly in response to the second 5 micrograms.min-1 dose, the reduction in each layer after indomethacin was comparable to that observed with the 5 micrograms.min-1 dose before indomethacin infusion. Finally, the in vitro production of PGI2 by coronary vessels was considerably impaired by indomethacin infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of serotonin on myocardial blood flow in the presence and absence of a coronary arterial stenosis: observations in domestic swine.

This study tested the hypothesis that 5-HT may impair coronary flow regulation by inappropriately increasing arteriolar tone in the coronary circulation. Ten closed chest, domestic swine were studied both in the presence and in the absence of a severe artificial intraluminal coronary stenosis. A 5-French micromanometer catheter with fluid lumen was placed in the left anterior descending coronary artery and used to record pressure and infuse 5-HT (40 and 100 micrograms/min) into the coronary circulation. For the stenosis phase of the protocol the catheter was embedded in the artificial stenosis. Hemodynamics, regional myocardial blood flow (microsphere technique), coronary vascular resistance, lactate consumption, and oxygen metabolism were measured at control and at 5 min of each 5-HT dose. In the absence of coronary artery stenosis (i.e., full vasodilatory reserve), there was no change in regional myocardial blood flow or coronary vascular resistance during 5-HT infusion. In the presence of a severe coronary stenosis (i.e., limited vasodilator reserve) 5-HT produced a significant (P less than 0.05) decrease versus control in the distal left anterior descending: circumflex zone endocardial blood flow ratio (0.63 +/- 0.19, mean +/- 1 SD, to 0.55 +/- 0.15) and a significant (P less than 0.05) increase versus control in endocardial (50.6 +/- 16.6 to 61.2 +/- 19.8 mm Hg/ml/min/g) and transmural (49.9 +/- 9.5 to 57.2 +/- 12.8) coronary vascular resistance. Thus, 5-HT does not impair coronary flow regulation when full vasodilatory reserve is present. When coronary vasodilatory reserve is impaired by the presence of a severe proximal stenosis, 5-HT causes modest impairment of endocardial flow regulation.

Experience with fully bioresorbable aortic grafts in the dog.

Reorganization of the arterial wall through natural processes on the resorption of a totally bioresorbable graft was investigated in dogs with Vicryl prostheses coated with two different blends of bioresorbable polyesters capable of slowing down considerably the disintegration of a Vicryl fabric in vivo. The prostheses (8 to 9 mm in internal diameter, 8 to 10 cm long) were implanted in the infrarenal aortic position for up to 24 weeks. All 18 animals implanted with coated prostheses survived, whereas one animal implanted with an uncoated Vicryl prosthesis died because of early rupture of the graft. Patent tubular conduits were present in 14 animals at the time of retrieval. On resorption of the synthetic polymers, the tissue layers that formed on both sides of the prosthetic material either fused or remained separated, depending on the polymer used as a retardant coating. We conclude that polymer composition influences the repair process and that a fully resorbable vascular graft can function effectively in a canine model, provided that tissue organization is sufficiently advanced by the time the prosthesis has lost its mechanical integrity. Further studies are needed to document the performance of the newly formed blood conduit over extended periods, in hypertensive subjects, and when presented with a bacterial challenge.

Tissue reaction to fabrics coated with turbostratic carbon: subcutaneous versus vascular implants.

A technique allowing the deposition of an adherent thin film of turbostratic, high-density carbon on heat-sensitive polymers was recently developed. The biological response to this biomaterial on yarns and fabrics of the type used in cardiovascular surgery has been studied. Polyester yarns, knitted Dacron sheets and knitted uncrimped Dacron vascular grafts were coated with a thin film (less than 1 micron) of turbostratic carbon using a physical vapour deposition process. Coated and control discs of knitted material, as well as coated and uncoated yarns, were implanted in pairs in the subcutaneous tissue of mice, using for each type of implant two cohorts of 12 animals, with observation periods of 4 and 8 wks respectively. Vascular grafts (8 cm long, 8 mm i.d.) coated with carbon on the luminal side only, were implanted for 12 wks in the infrarenal aortic position in six dogs, and compared to uncoated Dacron grafts of the same dimensions inserted in the same location and for the same duration in the infrarenal aortic position in six control animals. With subcutaneous implants, there was no significant difference in the tissue reaction to either coated or uncoated patches. In contrast, the vascular grafts, all of which were patent upon retrieval, showed a much lower extent of thrombosis on the blood-exposure surface in the case of carbon-coated Dacron, as compared to the luminal surface of control prostheses. The internal capsule (tissue formed between the polymer fabric and the blood interface) was thinner in carbon-coated grafts than in control grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired arteriolar vasodilation induced by thrombosis of a coronary arterial stenosis.

This study tested the hypothesis that aggregation of platelets and release of thromboxane A2 at the site of a coronary arterial stenosis may contribute to myocardial ischemia by impairing flow regulation of the distal coronary bed. Measurements of hemodynamics, flow (microspheres), lactate metabolism, and prostaglandin (PG) metabolites (thromboxane B2 and 6-keto-PGF1 alpha) were made in closed-chest anesthetized pigs instrumented with a stenosis (65% diam reduction) in the left anterior descending (LAD) coronary artery. Data were acquired prior to stenosis insertion (control) and 5 and 15 min after insertion, during which time thrombotic occlusion of the device was occurring. Heart rate was controlled by atrial pacing. Distal LAD zone endocardial flow (ml X min-1 X g-1) declined versus control (1.15 +/- 0.20, mean +/- SD) at 5 min (0.89 +/- 0.40, P less than 0.05) and 15 min (0.41 +/- 0.36, P less than 0.01) of occlusion. Distal endocardial resistance (mmHg X ml-1 X min X g), however, did not change versus control (72 +/- 12) at 5 (66 +/- 12) or 15 min (61 +/- 38). Distal epicardial resistance (mmHg X ml-1 X min X g) declined versus control (90 +/- 17) at 5 (66 +/- 35, P less than 0.05) and 15 min (43 +/- 26, P less than 0.01) postinsertion. Finally, lactate extraction (%) at control (42 +/- 19) changed to production 15 min postinsertion (-36 +/- 93, P less than 0.05) and arterial-anterior interventricular vein thromboxane B2 difference (pg/0.1 ml) changed from 13.1 +/- 17.8 pre to -15.8 +/- 30.0 at 5 min post (P less than 0.05). Thus platelet aggregation and release at a spontaneously thrombosing stenosis contribute to ischemia not only by reduction of stenosis diameter but also by impairment of flow regulation in endocardial layers distal to it.

Measurement by electrical impedance aggregometry of porcine platelets response to selected physiological agonists.

Although the domestic swine is commonly employed for physiological studies of the coronary circulation, there is relatively little data available concerning the responsiveness in whole blood of normal porcine platelets to standard physiological agonists. Such information is essential if the domestic swine is to be used as an animal model for studying potential interactions between platelets and the coronary circulation. Accordingly, the present study was undertaken to characterize the responses (aggregation and ATP release) observed in whole blood of normal porcine platelets to selected physiological agonists. The responses of platelets from 10 normal human volunteers also were studied with this system for comparison. Agents tested included ADP, arachidonic acid, collagen, epinephrine, norepinephrine, and thrombin. Studies were conducted with the Chronolog impedance aggregometer. The results demonstrate that platelets of domestic swine are reactive to ADP, arachidonic acid, and collagen. In contrast, neither epinephrine nor norepinephrine alone induced aggregation or release. Norepinephrine, however, caused modest potentiation of aggregation in response to ADP only. At 1 mM concentration each catecholamine inhibited the release response to collagen while at 10 mM each inhibited aggregation and release in response to either ADP or collagen. The data obtained indicate the domestic swine may be employed as a useful model to examine interactions between platelets and the coronary circulation.

Cutaneous lymphoma masquerading as granuloma faciale.

Granuloma faciale is a presumably benign disorder of the skin--usually of the face--characterized by a dense, polymorphous, inflammatory infiltrate including numerous eosinophils, separated from the epidermis by a clear or "grenz" zone, and possessing a small vessel, leukocytoclastic vasculitis. Primary malignant lymphoma of the skin, other than mycosis fungoides, is an unusual entity that may follow a widely variable course and is often extremely difficult to diagnose definitively. A patient is presented in whom a lesion consistent with granuloma faciale changed its histological appearance and clinical behavior into that of a malignant lymphoma.