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OBJECTIVE: Kaposi's sarcoma, the most common malignancy in AIDS patients, often presents with painful cutaneous lesions that are difficult to treat effectively despite a wide variety of therapeutic approaches. We used photodynamic therapy in an attempt to provide effective palliative treatment for this disease. METHODS: Photodynamic therapy utilizes the activation by light of a photosensitizing drug that preferentially accumulates in tumor tissue such as Kaposi's sarcoma. We enrolled 25 patients who received 1.0 mg/kg of Photofrin 48 h before exposure to 100-400 J/cm2 of 630 nm light. RESULTS: Of the 348 lesions treated, 289 were evaluable: 32.5% had complete clinical response, 63.3% had partial clinical response and 4.2% were clinical failures. There was a strong correlation between response and light dose: 54% of lesions achieved a complete clinical response at optimum light dose (> 250 J/cm2). There was no correlation of response with CD4 cell count nor was there a change in CD4 cell count post-treatment. At 400 J/cm2 full field scabbing and necrosis occurred in 90% of the treated fields. Thus, the maximum tolerated dose was determined to be 300 J/cm2. At light doses of 250 J/cm2 and below the toxicities were limited to erythema and edema in the treatment field. Forty-three biopsies were taken 0.5 h to 4 months post-treatment. These showed little change in the B and T cell infiltrates identified. Kaposi's sarcoma cells disappeared post-treatment in certain lesions. CONCLUSION: Photofrin is effective palliative treatment for HIV-associated Kaposi's sarcoma.

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OBJECTIVE: To determine whether inflamed and uninflamed epidermoid cysts differ in the number and/or type of bacteria inhabiting them. DESIGN: A controlled study. We obtained aerobic and anaerobic bacterial culture specimens from 25 inflamed and 25 uninflamed epidermoid cysts. SETTING: A university medical center. PATIENTS: Nonimmunocompromised adults without recent systemic use of antibiotics. RESULTS: The 2 groups did not differ significantly with respect to number of bacterial isolates, "no growth" cultures, and aerobic, anaerobic, or potential pathogens cultured. CONCLUSIONS: The microbiological milieu of inflamed epidermoid cysts is similar to that of uninflamed cysts. Possible mechanisms for inflammation are discussed.

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BACKGROUND: Lymphoepithelioma-like carcinoma of the skin (LELCS) is a rare malignant tumor thought to be of adnexal origin. Because of its rarity, treatment parameters have not been defined. OBJECTIVE: To examine the role and success of Mohs micrographic surgery in the treatment of LELCS versus other forms of treatment previously documented in the literature. METHODS/RESULTS: A review of the previous reported cases and their treatment outcomes was compared with the present case. Three of the 12 previously reported cases were incompletely treated with initial surgical management, with one patient subsequently dying of metastatic tumor. The present case was treated with Mohs micrographic surgery for recurrent LELCS, following initial treatment with electrodessication and curettage, and is without evidence of disease 20 months postoperatively. CONCLUSION: LELCS may be successfully treated by Mohs micrographic surgery.

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BACKGROUND: Developmental work in tattoo removal is currently carried out in animal models whose skin has different optical and mechanical properties from human skin. OBJECTIVE: To observe laser effects on tattoos in a new human skin model and that of in vivo guinea pig skin. METHODS: A comparison of the efficacy of the Q-switched Alexandrite laser (750 nm, 100-120 nanoseconds) in tattooed harvested human skin and guinea pig skin was performed. Visual assessments as well as histologic and electron microscopy evaluation before and after treatment are reported. RESULTS: Mild to moderate clearing of black tattoo pigment, as judged by visual assessment, was found after one laser treatment in both the in vitro human skin model and guinea pig skin. Blue and green ink showed similar results to black ink in human skin whereas red and yellow ink did not respond in our model. CONCLUSION: Possible mechanisms of tattoo lightening and the usefulness of the in vitro human skin model are discussed.

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A neurilemmoma usually presents as a solitary subcutaneous tumor adherent to a peripheral nerve. Multiple localized neurilemmomas may occur as an isolated cutaneous finding or as part of the syndrome of neurilemmomatosis. We report a case of multiple neurilemmomas appearing on an extremity after trauma. The multiplicity and localization of the tumors are rare and illustrate that neurilemmomas are not invariably solitary tumors and that their distribution can be regional. We review the previously reported cases of multiple neurilemmomas and review the characteristics that help the clinician to differentiate between multiple localized neurilemmomas and neurilemmomatosis.

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Interactions between calcium antagonists (CA) and muscle relaxants have been reported however due to the extremely high dosages of CA used in these studies, the clinical relevance of the observed interactions has been questioned. In order to simulate clinical practice--which entails long-term oral treatment and significant reductions in systolic blood pressure--CA were administered to rats orally (by gavage) for 8 days at a dosage that induced a systolic blood pressure decrease of not more than 25 +/- 5 mmHg. Ten groups of six male Sprague-Dawley rats each, body weight (BW) 313 +/- 23 g, were subjected to oral administration of three different CA: nitrendipine (1 mg/kg BW), nisoldipine (1 mg/kg BW), and diltiazem (100 mg/kg BW) or their solvents (control) three times daily by gavage for a period of 8 days. One hour after the last dose of drug or solvent, the rats were anesthetized (pentobarbital 60 mg/kg BW) and mechanically ventilated via tracheostomy. Monitoring included rectal temperature, carotid artery pressure, central venous pressure, heart rate, blood gases, and end-tidal CO2. Evoked train-of-four (T4) twitch tension of the right tibialis anterior muscle was recorded continuously. After equilibration of vital signs and muscle twitch tension, vecuronium (150 micrograms/kg BW) or atracurium (500 micrograms/kg BW) was injected into the internal jugular vein four times at 5-min intervals after twitch tension had totally recovered and T4 fade had disappeared. Twitch depression, duration 90, and onset time of neuromuscular block in CA-pretreated animals were compared to control animals.(ABSTRACT TRUNCATED AT 250 WORDS)

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Malignant hyperthermia (MH) is a genetic disease of man, swine, dogs, cats, and horses. The syndrome is normally triggered by inhalational anesthetics or the administration of depolarizing muscle relaxants such as succinylcholine or various environmental stress factors. We have used the MH-susceptible pig as an animal model to study the hormonal changes developing during this highly lethal syndrome. High-performance liquid chromatography with electrochemical detection was used for the quantitation of the plasma levels of norepinephrine and epinephrine during MH. This research presents evidence that the rapid release of massive quantities of norepinephrine (up to 108 ng/ml) into the blood stream occurs simultaneously with the initiation of tachycardia which is the herald signal of the onset of MH. Norepinephrine levels exceed epinephrine by a 4:1 ratio early in the syndrome. Even pigs with MH which do not develop the muscle rigor phase have high levels of circulating norepinephrine. Tachycardia, pulmonary hypertension, increased venous oxygen desaturation, and increasing core temperature develop as the syndrome progresses.

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The ability of diltiazem to suppress halothane and halothane-caffeine induced contractures in malignant hyperthermia (MH) susceptible pig muscle, was tested in vitro. Muscle specimens were divided into two groups and tested with a modified halothane-caffeine contracture test. One group acted as the control; the other group was pretreated with diltiazem 20 mumol litre-1. The control muscles developed contractures attributable to halothane and halothane-caffeine, whereas the diltiazem-treated specimens did not. Increases in muscle twitch tension as a result of halothane or halothane-caffeine exposure occurred in treated and untreated specimens, but were significantly delayed in the presence of diltiazem. Muscle exhaustion observed after halothane and halothane-caffeine exposure in the control specimens did not occur in the diltiazem treated muscles.

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Vecuronium was studied in eight malignant hyperthermia (MH) susceptible pigs for its potential to either trigger or prevent MH. Two sets of experiments were performed in the same animals: 1-hr total neuromuscular blockade by vecuronium infusion with thiopental anesthesia in the absence of invasive monitoring and halothane; and 1-hr infusion of vecuronium with thiopental anesthesia with invasive monitoring in the absence of and then, followed by 30-min infusion in the presence of halothane, followed in turn by exposure to halothane alone. One-hour infusion of vecuronium in the absence of halothane and invasive monitoring did not trigger MH in any animal. During the second set of experiments, MH, evidenced by rising rectal temperature, elevated end-tidal PCO2, mixed venous oxygen desaturation and muscle rigor, occurred in one animal during vecuronium alone, in four animals during vecuronium infusion and simultaneous exposure to halothane, and in three animals during exposure to halothane alone after recovery from vecuronium neuromuscular blockade. In view of the results of control experiments, the development of MH during vecuronium neuromuscular blockade before exposure to halothane was attributed to surgical stress rather than to vecuronium itself. It is concluded that vecuronium is not a trigger to MH in susceptible pigs.

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