Conjunctival nevi in Denmark 1960-1980. A 21-year follow-up

The clinicopathological characteristics of 343 naevi of the conjunctiva were studied. A significant increase in the number of naevi excised per year was observed. This may have been caused by an increased exposure to actinic rays. An approximately even distribution was found between the three main locations: caruncle, limbal area and eye ball. Intrastromal naevi were excised at a higher median age than compound naevi, and the lowest median age at excision was for junction naevi, which is in accordance with the known histopathological nature of naevi. Recurrence occurred in nine patients (2.7%), and one had transformed into a malignant melanoma. Eight of the recurring naevi were located in the limbal area. Eight of the nine patients were women, suggesting hormonal factors as a possible cause. Recommendations for the handling of conjunctival naevi are given, based on the present findings and on previous reports.     

Preservation with 8-bromo-cyclic GMP improves pulmonary function after prolonged ischemia

BACKGROUND: Cyclic guanosine monophosphate (cGMP) is a potent second messenger for the nitric oxide pathway in the pulmonary vasculature. Increased cytosolic cGMP levels elicit pulmonary vasodilatation resulting in decreased pulmonary vascular resistance and maximized pulmonary function after ischemia-reperfusion injury. We hypothesized that the addition of a membrane-permeable cGMP analogue (8-bromo-cGMP) to a Euro-Collins (EC) preservation solution would ameliorate pulmonary reperfusion injury better than prostaglandin E1 injection alone after prolonged hypothermic ischemia. METHODS: All lungs from New Zealand White rabbits (weight, 3 to 3.5 kg) were harvested en bloc, flushed with EC solution, and reperfused with whole blood for 30 minutes. Group 1 lungs (immediate control) were immediately reperfused. Group 2 lungs (control) were stored inflated at 4 degrees C for 18 hours before reperfusion. Groups 3 and 4 lungs were flushed with EC solution containing 200 micromol/L 8-bromo-cGMP and stored at 4 degrees C for 18 and 30 hours, respectively. Fresh, nonrecirculated venous blood was used to determine single-pass pulmonary venous-arterial oxygen gradients at 10-minute intervals. Assays for cGMP, cyclic adenosine monophosphate, nitric oxide synthase activity, and myeloperoxidase were performed on all lung tissue samples. Wet to dry weight ratios were determined after 2 weeks of passive desiccation. RESULTS: Oxygenation (venous-arterial oxygen gradient), pulmonary artery pressure, pulmonary vascular resistance, and edema formation were significantly improved in groups 3 and 4 (addition of 8-bromo-cGMP to EC plus 18 or 30 hours of hypothermic ischemia). Hypothermic storage (groups 2, 3, and 4) decreased both nitric oxide synthase activity and myeloperoxidase levels compared with immediate reperfusion (group 1). CONCLUSIONS: These results suggest that the addition of a membrane-permeable cGMP analogue to an EC pulmonary flush solution improves pulmonary function after prolonged storage compared with EC and prostaglandin (E1) preservation alone. The finding of myeloperoxidase reduced levels after hypothermic storage and subsequent reperfusion may suggest a more important role for pulmonary hemodynamic control in mitigating pulmonary reperfusion injury.     

Localization of metallothionein-I and -III expression in the CNS of transgenic mice with astrocyte-targeted expression of interleukin 6

The effect of interleukin-6 (IL-6) on metallothionein-I (MT-I) and MT-III expression in the brain has been studied in transgenic mice expressing IL-6 under the regulatory control of the glial fibrillary acidic protein gene promoter (GFAP-IL6 mice), which develop chronic progressive neurodegenerative disease. In situ hybridization analysis revealed that GFAP-IL6 (G16-low expressor line, and G36-high expressor line) mice had strongly increased MT-I mRNA levels in the cerebellum (Purkinje and granular layers of the cerebellar cortex and basal nuclei) and, to a lesser degree, in thalamus (only G36 line) and hypothalamus, whereas no significant alterations were observed in other brain areas studied. Microautoradiography and immunocytochemistry studies suggest that the MT-I expression is predominantly localized to astrocytes throughout the cerebrum and especially in Bergman glia in the cerebellum. However, a significant expression was also observed in microglia of the GFAP-IL6 mice. MT-III expression was significantly increased in the Purkinje cell layer and basal nuclei of the cerebellum, which was confirmed by Northern blot analysis of poly(A)+ mRNA and by ELISA of the MT-III protein. In contrast, in the G36 but not G16 mice, transgene expression of IL-6 was associated with significantly decreased MT-III RNA levels in the dentate gyrus and CA3 pyramidal neuron layer of the hippocampus and, in both G36 and G16 mice, in the occipital but not frontal cortex and in ependymal cells. Thus, both the widely expressed MT-I isoform and the CNS specific MT-III isoform are significantly affected in a MT isoform- and CNS area-specific manner in the GFAP-IL6 mice, a chronic model of brain damage.     

Mutations in either nucleotide-binding site of P-glycoprotein (Mdr3) prevent vanadate trapping of nucleotide at both sites

Vanadate trapping of nucleotide and site-directed mutagenesis were used to investigate the role of the two nucleotide-binding (NB) sites in the regulation of ATP hydrolysis by P-glycoprotein (mouse Mdr3). Mdr3, tagged with a hexahistidine tail, was overexpressed in the yeast Pichia pastoris and purified to about 90% homogeneity by Ni-affinity chromatography. This protocol yielded purified, reconstituted Mdr3 which exhibited high verapamil stimulation of ATPase activity with a Vmax of 4.2 micromol min-1 mg-1 and a KM of 0.7 mM, suggesting that Mdr3 purified from P. pastoris is highly functional. Point mutations were introduced into the core consensus sequence of the Walker A or B motifs in each of the two NB sites. The mutants K429R, K1072R (Walker A) and D551N, D1196N (Walker B) were functionally impaired and unable to confer cellular resistance to the fungicide FK506 in the yeast Saccharomyces cerevisiae. Single and double mutants (K429R/K1072R, D551N/D1196N) were expressed in P. pastoris, and the effect of these mutations on the ATPase activity of Mdr3 was characterized. Purified reconstituted Mdr3 mutants showed no detectable ATPase activity compared to proteoliposomes purified from negative controls (<5% of wild-type Mdr3). Vanadate readily induced trapping of 8-azido-nucleotide in the wild-type enzyme after a short 10 s incubation, and specific photolabeling of Mdr3 after UV irradiation. No such vanadate-induced trapping/photolabeling was observed in any of the mutants, even after a 60 min trapping period at 37 degrees C. Since vanadate trapping with 8-azido-ATP requires hydrolysis of the nucleotide, the data suggest that 8-azido-ATP hydrolysis is dramatically impaired in all of the mutant proteins (<0.3% activity). These results show that mutations in either NB site prevent single turnover and vanadate trapping of nucleotide in the nonmutant site. These results further suggest that the two NB sites cannot function independently as catalytic sites in the intact molecule. In addition, the N- or C-terminal NB sites appear functionally indistinguishable, and cooperative interactions absolutely required for ATP hydrolysis may originate from both sites.     

Thyroid hormone-induced alterations in phospholamban-deficient mouse hearts

Total serum IgE, Phadiatop, and the skin prick test (SPT) are commonly used to diagnose atopic diseases. However, no large study has ever been done to test their diagnostic efficiency. We studied the diagnostic value of these three atopic markers in 8329 well-randomized adults from the Swiss Population Registry. The prevalence of current allergic asthma (CAA) was 1.8% and of current allergic rhinitis (CAR) 16.3%. The prevalences of positive Phadiatop, positive SPT (at least, one out of eight SPT to common aeroallergens with a wheal of > or = 3 mm), and positive total IgE (IgE > or = 100 kU/l) were 29, 23, and 23%, respectively. To diagnose CAA and CAR, the sensitivity of Phadiatop was significantly higher than that of SPT (72.5% vs 65.4%, 77.1% vs 68.4% respectively; P < 0.01 and < 0.001) and IgE (72.5% vs 56.9%, 77.1% vs 43.9%, respectively; both P < 0.001). The sensitivity of SPT was significantly higher (68.4% vs 43.9% P < 0.001) than that of IgE to diagnose CAR. When CAA and CAR were excluded, the SPT specificity was significantly higher than that of Phadiatop (77.8% vs 71.9% and 85.9% vs 80.5%, respectively; both P < 0.001): when CAR was excluded, SPT was significantly higher than IgE (85.9 vs 81.4%; P < 0.001). SPT had significantly the best positive predictive value for CAA (5.2% for SPT vs 4.6% for both IgE and Phadiatop; both P < 0.001) and CAR (48.7% for SPT vs 43.5% for Phadiatop and 31.6% for IgE; both P < 0.001). The three markers of atopy had roughly the same negative predictive value (NPV) for CAA, but IgE had a significantly lower NPV for CAR than SPT and Phadiatop (88.1% vs 93.3% and 94.7%, respectively; both P < 0.001). The diagnostic efficiency of SPT was significantly higher than that of Phadiatop (83.1% vs 79.9% and 77.6 vs 71.9%, respectively; both P < 0.001) to diagnose CAR and CAA. IgE and SPT had equal efficiency (77.6%), which was significantly higher than that of Phadiatop, to diagnose CAA (71.9%; both P < 0.001). In conclusion, SPT have the best positive predictive value and the best efficiency to diagnose respiratory atopic diseases. Furthermore, SPT give information on sensitivity to individual allergens and should therefore be used primarily by clinicians to assess respiratory allergic diseases. Moreover, they are cheaper and provide immediate, educational information for both patient and physician.     

Effect of the novel antiplatelet agent cilostazol on plasma lipoproteins in patients with intermittent claudication

Cilostazol is an antiplatelet agent and vasodilator marketed in Japan for treatment of ischemic symptoms of peripheral vascular disease. It is currently being evaluated in the United States for treatment of symptomatic intermittent claudication (IC). Cilostazol has been shown to improve walking distance in patients with IC. In addition to its reported vasodilator and antiplatelet effects, cilostazol has been proposed to have beneficial effects on plasma lipoproteins. We examined the effect of cilostazol versus placebo on plasma lipoproteins in 189 patients with IC. After 12 weeks of therapy with 100 mg cilostazol BID, plasma triglycerides decreased 15% (P<0.001). Cilostazol also increased plasma high density lipoprotein cholesterol (HDL-C) (10%) and apolipoprotein (apo) A1 (5.7%) significantly (P<0.001 and P<0.01, respectively). Both HDL3 and HDL2 subfractions were increased by cilostazol; however, the greatest percentage increase was observed in HDL2. Individuals with baseline hypertriglyceridemia (>140 mg/dL) experienced the greatest changes in both HDL-C and triglycerides with cilostazol treatment. In that subset of patients, HDL-C was increased 12.2% and triglycerides were decreased 23%. With cilostazol, there was a trend (3%) toward decreased apoB as well as increased apoA1, resulting in a significant (9.8%, P<0.002) increase in the apoA1 to apoB ratio. Low density lipoprotein cholesterol and lipoprotein(a) concentrations were unaffected. Cilostazol treatment resulted in a 35% increase in treadmill walking time (P=0.0015) and a 9.03% increase in ankle-brachial index (P<0.001). These results indicate that in addition to improving the symptoms of IC, cilostazol also favorably modifies plasma lipoproteins in patients with peripheral arterial disease. The mechanism of this effect is currently unknown.     

The renal and hepatic distribution of Bence Jones proteins depends on glycosylation: a scintigraphic study in rats

The aim of the present study was to evaluate renal and liver distribution of two monoclonal immunoglobulin light chains. The chains were purified individually from the urine of patients with multiple myeloma and characterized as lambda light chains with a molecular mass of 28 kDa. They were named BJg (high amount of galactose residues exposed) and BJs (sialic acid residues exposed) on the basis of carbohydrate content. A scintigraphic study was performed on male Wistar rats weighing 250 g for 60 min after i.v. administration of 1 mg of each protein (7.4 MBq), as the intact proteins and also after carbohydrate oxidation. Images were obtained with a Siemens gamma camera with a high-resolution collimator and processed with a MicroDelta system. Hepatic and renal distribution were established and are reported as percent of injected dose. Liver uptake of BJg was significantly higher than liver uptake of BJs (94.3 vs 81.4%) (P < 0.05). This contributed to its greater removal from the intravascular compartment, and consequently lower kidney accumulation of BJg in comparison to BJs (5.7 vs 18.6%) (P < 0.05). After carbohydrate oxidation, there was a decrease in hepatic accumulation of both proteins and consequently a higher renal overload. The tissue distribution of periodate-treated BJg was similar to that of native BJs: 82.7 vs 81.4% in the liver and 17.3 vs 18.6% in the kidneys. These observations indicate the important role of sugar residues of Bence Jones proteins for their recognition by specific membrane receptors, which leads to differential tissue accumulation and possible toxicity.     

Low-dose sodium nitroprusside reduces pulmonary reperfusion injury

BACKGROUND: Reperfusion injury is a significant cause of early allograft dysfunction after lung transplantation. We hypothesized that direct pulmonary arterial infusion of an intravascular nitric oxide donor, sodium nitroprusside (SNP), would ameliorate pulmonary reperfusion injury more effectively than inhaled nitric oxide without causing profound systemic hypotension. METHODS: Using an isolated, ventilated, whole-blood-perfused rabbit lung model, we studied the effects of both inhaled and intravascular nitric oxide during lung reperfusion. Group I (control) lungs (New Zealand White rabbits, 3 to 3.5 kg) were harvested en bloc, flushed with Euro-Collins solution, and then stored inflated for 18 hours at 4 degrees C. Lungs were then reperfused with whole blood and ventilated with 60% oxygen for 30 minutes. Groups II, III, and IV received pulmonary arterial infusions of SNP at 0.2, 1.0, and 5.0 micrograms.kg-1.min-1, respectively, whereas group V was ventilated with 60% oxygen and nitric oxide at 80 ppm during reperfusion. RESULTS: Pulmonary arterial infusions of SNP even at 0.2 microgram.kg-1.min-1 (group II) showed significant improvements in pulmonary artery pressure (31.35 +/- 0.8 versus 40.37 +/- 3.3 mm Hg; p < 0.05) and pulmonary vascular resistance (38,946 +/- 1,269 versus 52,727 +/- 3,421 dynes.s/cm-5; p < 0.05) when compared with control (group I) lungs after 30 minutes of reperfusion. Infusions of SNP at 1.0 microgram.kg-1.min-1 (group III) showed additional significant improvements in dynamic airway compliance (1.98 +/- 0.10 versus 1.46 +/- 0.02 mL/mm Hg; p < 0.05), venous-arterial oxygenation gradient (116.00 +/- 24.4 versus 34.43 +/- 2.5 mm Hg; p < 0.05), and wet-to-dry ratio (6.9 +/- 0.9 versus 9.1 +/- 2.2; p < 0.05) when compared with control (group I) lungs. Lungs that received inhaled nitric oxide at 80 ppm (group V) were significantly more compliant (1.82 +/- 0.13 versus 1.46 +/- 0.02 mL/mm Hg; p < 0.05) than control (group I) lungs. CONCLUSIONS: Pulmonary arterial infusion of low-dose SNP during lung reperfusion significantly improves pulmonary hemodynamics, oxygenation, compliance, and edema formation. These effects were achieved at doses of SNP that did not cause profound systemic hypotension. Direct intravascular infusion of SNP via pulmonary arterial catheters could potentially abate reperfusion injury immediately after allograft implantation.