Acute endotoxemia protracts leukocyte / endothelium interaction after local ischemia and reperfusion in striated muscle

Postischemic reperfusion injury and endotoxemia have been shown to promote multiple organ failure in polytraumatized patients. Both pathomechanisms comprise endothelial injury, leukocyte activation, and enhanced leukocyte/endothelium interaction in the microcirculation. Using a dorsal skinfold chamber model for intravital microscopy in striated muscle of awake hamsters, we investigated whether acute endotoxemia enhances postischemic leukocyte/endothelium interaction. - In control animals (n = 8), reperfusion after 2 hours of pressure induced ischemia elicited the rolling and adhesion of fluorescently stained leukocytes to the endothelium of postcapillary venules with a maximum at 0.5 and 2 hours after reperfusion and a decline towards preischemic values after 24 hours. Postischemic leukocyte adhesion was enhanced and protracted in animals where acute endotoxemia was induced through intravenous injection of endotoxin (Salmonella abortus equi, 0.1 microg¿kg superset-1) either 10 minutes prior to ischemia (n = 8) or to reperfusion (n = 8). - These results suggest that acute endotoxemia has the potential to aggravate the leukocyte-triggered reperfusion damage to striated muscle and presumably to vital organs and thus favours the development of multiple organ failure after primarily successful reperfusion.

Role of L-selectin in leukocyte sequestration in lung capillaries in a rabbit model of endotoxemia

After a variety of pathophysiologic stimuli, neutrophils accumulate in lung capillaries and contribute to the pathogenesis of acute lung injury. Lung neutrophil sequestration has previously been attributed to mechanical retention of stiffened neutrophils, but L-selectin-mediated leukocyte/endothelial interaction may be an essential step. We investigated the effect of the anti-L-selectin antibody HuDreg 200 on leukocyte sequestration and microhemodynamics in alveolar capillaries in a model of acute endotoxemia. We used in vivo fluorescence microscopy to analyze kinetics of fluorescently labeled red and white blood cells in alveolar capillary networks of the rabbit lung. Investigations were performed over 2 h after an intravenous infusion of 0.2 ml/kg body weight (bw) NaCl, 2 mg/kg bw HuDreg 200, 20 microg/kg bw lipopolysaccharide (LPS) of Escherichia coli 0111:B4, or the combination of HuDreg 200 and LPS, respectively. Infusion of LPS induced leukocyte sequestration in alveolar capillaries, which was accompanied by a reduction of alveolar capillary perfusion and functional capillary density. These effects could be completely blocked by pretreatment of animals with HuDreg 200. We conclude that L-selectin-mediated leukocyte/endothelial interaction is a necessary prerequisite for leukocyte sequestration in alveolar capillaries in this model. Impaired alveolar capillary perfusion appeared to result directly from capillary leukocyte sequestration.

[Effect of humanised anti-L- selectin antibody HuDreg 200 on leukocyte kinetics in pulmonary microcirculation in endotoxinemia]

In the pulmonary circulation, endotoxemia induces leukocyte/endothelium interaction in pulmonary arterioles and venules. Thus, leukocytes may contribute to the pathogenesis of acute lung injury. In order to investigate, whether this interaction can be inhibited by early blockade of the adhesion cascade, we studied the effect of the humanized anti-L-selectin antibody HuDreg 200 on leukocyte kinetics in pulmonary arterioles and venules following i.v.-infusion of endotoxin. In endotoxemia HuDreg 200 reduces sticking of leukocytes in both pulmonary arterioles and venules. Thus, we were able to demonstrate that early blockade of the adhesion cascade effectively prevents leukocyte accumulation in pulmonary microvessels in endotoxemia. Therefore, HuDreg 200 may exhibit protective effects on the manifestation of leukocyte-mediated acute lung injury.

Phacolytic glaucoma and lens-induced uveitis

The pathogenesis of lens-induced uveitis and phacolytic glaucoma is still not fully understood. The authors report a case of a 62-year-old white female, with bilateral lens dislocation into the vitreous, who presented clinical and pathological features of phacolytic glaucoma in the left eye. The ultrastructural study of aqueous and vitreous aspirates showed lenticular fragments and macrophages with lipofuscin granules and phagocytic vacuoles containing lens proteins. Immunocytochemistry revealed foamy macrophages immunoreactive for CD68 and HLA-DR. One year later the right eye disclosed a mild anterior granulomatous uveitis with corneal mutton-fat keratic precipitates that remained unchanged in the course of sixteen months follow-up without further treatment. These findings corroborate the possibility that, besides their mechanical and inflammatory roles in the impairment of the outflow system of the (exciting) left eye, phacolytic macrophages might also have been involved in the afferent phase of the mild chronic uveitis of the (fellow) right eye.

Percutaneous transluminal ultrasonic angioplasty: preliminary clinical report of ultrasound plaque ablation in totally occluded peripheral arteries

Peripheral arterial obstructive disease has been treated with ultrasound ablation. Thirty two patients (pts), mean age 67 +/- 10 years underwent angiosonoplasty, with a prototype ultrasonic system, due to severe claudication (31%), rest pain (44%), rest pain and ulceration (25%). Angiosonoplasty was successful in 26/32 (81%) stenoses, (1/2 iliac, 9/2 femorals, 11/12 popliteal, 5/6 tibial). Angiography before and after angiosonoplasty confirmed that the lesions were successfully opened, (81%, p less than 0.05). A mean of 3 +/- 2 passes were required to adequately remove sufficient plaque. Balloon angioplasty was used in combination with angiosonoplasty in 11/32 (34%) occluded vessels. Complications included groin hematoma in 4 pts (12%) and vascular spasm in two patients (6%). Within 24 hours, 27/32 (94%) pts were discharged clinically improved. Reocclusion occurred in 4 pts (12%) immediately after the procedure. Ankle brachial indices significantly increased from 0.52 +/- 0.10 before to 0.70 +/- 0.12 after (p less than 0.05). In conclusion, the use of ultrasound energy to ablate atherosclerotic plaque would appear safe, and has shown no restenosis and a low incidence of complications over a six month period.

Effects of repeated photic exposures on the monkey macula

The posterior pole of the eyes of rhesus monkeys was exposed to the light of an indirect ophthalmoscope. The tissue changes caused by repeated (three to five) photic injuries were compared with those produced by a single photic insult. The ophthalmoscopic and angiographic examinations showed a progressive involvement of the foveal area after multiple exposures to light. Histopathologic study showed that after one exposure the retinal pigment epithelium appeared focally atrophic. Plaques of proliferated retinal pigment epithelium could also be seen, and on the anterior surface of these plaques a layer of relatively cuboidal hypopigmented retinal pigment epithelial cells was present. With multiple exposures, focal areas of total absence of retinal pigment epithelium were seen in these eyes. The eyes that received only one exposure showed partially regenerated photoreceptor outer segments. After repeated photic exposures, the photoreceptor outer segments failed to regenerate even 6 to 8 months after the last exposure. In one eye exposed five times for 60 minutes, areas of total absence of photoreceptor cells could be seen, and the inner nuclear layer was directly apposed to Bruch's membrane. These experimental exposures to the light of an indirect ophthalmoscope were 60 to 120 minutes long and were not comparable to clinical exposures of the ophthalmoscope in patient examination. Our observation highlighted the cumulative effects of repeated light injury to the retinal pigment epithelial and photoreceptor cells and also showed the similarity between this animal model of photic maculopathy and the changes present in the eyes of human patients with atrophic agerlated macular degeneration.

Magnetic resonance imaging in retinoblastoma and retinocytoma: a case report

Magnetic resonance imaging (MRI) is playing a growing role in the evaluation of ocular and orbital tumors. We report the case of a 26-month-old child presenting an undifferentiated retinoblastoma with a differentiated retinocytoma component in his left eye. After the eye was enucleated, we could correlate the clinicopathologic findings with the MRI scans. Both the undifferentiated retinoblastoma and the differentiated retinocytoma components could be determined on magnetic resonance imaging. Because different levels of metabolic activity within a tumor mass may influence largely T1 and T2 parameters, accurate determination of these values may be useful in determining the differentiation of a retinoblastoma, enabling a better therapeutic approach and assessment of the response to treatment.

Study of a new analgesic compound in the treatment of tension headache

The effect of a new analgesic compound (propoxyphene, acetaminophen, caffeine, hydroxyzine) was investigated in a single-blind study comparing it with plain acetaminophen administered to forty patients with tension headache. For the study, patients were assigned to one of two groups of twenty each. Starting dose for each group was one to two tablets followed by one tablet every four to six hours. The results show that 90% clinical success was obtained with the analgesic compound, while a 45% success was obtained with plain acetaminophen. This is a statistically significant difference. Side-effects observed with analgesic compound were primarily drowsiness and dizziness of mild intensity; acetaminophen caused gastro-intestinal alterations (nausea, vomiting) and dizziness of greater severity. Therapy was withdrawn in 20% of patients taking acetaminophen because of side-effects. The dosage of analgesic compound required to control each episode of tension headache was smaller than that of acetaminophen. These results can be explained by a possible potentiation of pharmacological activity of the compound's components. It can be concluded that the analgesic compound is a new and effective combination for the symptomatic treatment of tension headache.

Manual Colorimetric Methods for Pseudocholinesterase and Red Cell (True) Cholinesterase

This report describes both an improved version of Garry and Routh’s colorimetric assay for serum pseudocholinesterase [Clin. Chem. 11, 91 (1965)] and a variation of this method for use in measuring cholinesterase in red cells. These procedures require either 0.1 ml of serum (diluted 10-fold) cr 0.1 ml of packed, heparinized erythrocytes (diluted 100-fold). The reaction involves the hydrolysis of acetylthiocholine to acetic acid and thiocholine, and the quantitation of the thiocholine with 5,5'-dithiobis-2-nitrobenzoic acid. In the procedure, the sample of diluted serum or cells is added to the combined buffer—color-substrate reagent at 37°C. After incubation for 10 min, quinidine sulfate is added to retard the reaction and the color is read at 450 nm. Blanks are required with each red cell sample, but not for sera. The results correlate well with those obtained by Michel’s standard ΔpH assay, Kalow’s benzoylcholine uv-rate reaction, Caraway’s colorimetric procedure, and Ellman’s colorimetric rate reaction. A method for determination of dibucaine-inhibited serum pseudocholinesterase is also described.