Localization of Mycobacterium avium-intracellulare within a skin lesion of bacillary angiomatosis in a patient with AIDS.

We report a 39-year-old man who had AIDS and who presented with an unusual cutaneous vascular lesion, which was clinically thought to be Kaposi's sarcoma. Histologically, the lesion was characterized by capillary proliferation and a mixed inflammatory infiltrate that included numerous histiocytes. The lesion was found to contain slender intracellular acid-fast bacilli, as well as plump extracellular Warthin-Starry-positive bacilli. The acid-fast bacilli were confirmed to be Mycobacterium avium-intracellulare by subsequent positive blood cultures for this organism. To further investigate the lesion, polymerase chain reaction DNA amplification and sequencing was performed, and the lesion was found to contain DNA sequences identical to those previously established for the agent of bacillary angiomatosis. The lesion is thought to represent a lesion of bacillary angiomatosis with secondary involvement by M. avium-intracellulare.     

Regulation of cardiac cAMP synthesis and contractility by nucleoside diphosphate kinase B/G protein beta gamma dimer complexes

Heterotrimeric G proteins are pivotal regulators of myocardial contractility. In addition to the receptor-induced GDP/GTP exchange, G protein alpha subunits can be activated by a phosphate transfer via a plasma membrane-associated complex of nucleoside diphosphate kinase B (NDPK B) and G protein betagamma-dimers (Gbetagamma). To investigate the physiological role of this phosphate transfer in cardiomyocytes, we generated a Gbeta1gamma2-dimer carrying a single amino acid exchange at the intermediately phosphorylated His-266 in the beta1 subunit (Gbeta1H266Lgamma2). Recombinantly expressed Gbeta1H266Lgamma2 were integrated into heterotrimeric G proteins in rat cardiomyocytes but were deficient in intermediate Gbeta phosphorylation. Compared with wild-type Gbeta1gamma2 (Gbeta1WTgamma2), overexpression of Gbeta1H266Lgamma2 suppressed basal cAMP formation up to 55%. A similar decrease in basal cAMP production occurred when the formation of NDPK B/Gbetagamma complexes was attenuated by siRNA-mediated NDPK B knockdown. In adult rat cardiomyocytes expressing Gbeta1H266Lgamma2, the basal contractility was suppressed by approximately 50% which correlated to similarly reduced basal cAMP levels and reduced Ser16-phosphorylation of phospholamban. In the presence of the beta-adrenoceptor agonist isoproterenol, the total cAMP formation and contractility were significantly lower in Gbeta1H266Lgamma2 than in Gbeta1WTgamma2 expressing cardiomyocytes. However, the relative isoproterenol-induced increased was not affected by Gbeta1H266Lgamma2. We conclude that the receptor-independent activation of G proteins via NDPK B/Gbetagamma complexes requires the intermediate phosphorylation of G protein beta subunits at His-266. Our results highlight the histidine kinase activity of NDPK B for Gbeta and demonstrate its contribution to the receptor-independent regulation of cAMP synthesis and contractility in intact cardiomyocytes.     

Postoperative beta radiation treatment of pterygium

A retrospective analysis of 69 patients with diagnosis of pterygium who underwent surgical removal of the pterygium and postoperative beta radiation from a Strontium-90 (Sr-90) applicator from January, 1973, to December, 1977, is presented. The radiation treatment was delivered 2–48 hrs postoperatively after surgical removal of the pterygium. Those few patients who received beta radiation after more than 56 hours postoperatively were not included in the analysis because of the small number of patients in this group. Thirty-two patients had bilateral pterygium; 18 patients from this group received radiation treatment to one eye only. A total of 83 eyes have been irradiated in the whole group. A total dose of 1800–2200 rad equivalent of beta radiation was delivered to the edge of the cornea and surgical bed of the pterygium in the conjunctiva. Measurement by phantom showed that the dose to the anterior surface of the lens will be approximately 70–90 rad, and the dose to the retina will be 4–8 rad during a single dose of 1800–2200 rad equivalent of beta radiation to the conjunctiva and pterygium bed. Thirty-nine percent of the nonirradiated eyes after removal of the pterygium developed recurrence, whereas only 5% of the irradiated eyes developed recurrence. Nineteen percent of the irradiated eyes developed cataract as well as 10% of the nonirradiated eyes. These include all detectable cataracts, some of which did not require lens removal. Local cortisone therapy reduced the progression of the recurrent disease for a few months and partial regression was seen in four eyes, but there was no complete regression of any recurrent pterygium with topical cortisone therapy. This retrospective study showed that postoperative 1800–2200 rad beta radiation from a Strontium-90 applicator, if delivered 2–48 hours postoperatively, is effective in reducing the recurrence rate. It has acceptable range of complication if it is administered by an experienced radiation therapist and calculation and calibration are done precisely. The immediate and late side effects and complications of beta radiation from a Strontium applicator are discussed, and the dose delivered to the cornea, sclera, lens, and retina with this radiation treatment are shown.     

Expression of nitric oxide related enzymes in coronary heart disease

Enzymes involved in the metabolism nitric oxide (NO) and reactive oxygen species (ROS) may play a role for the decreased availability of NO in atherosclerosis. We, therefore, hypothesized that the pattern of gene expression of these enzymes is altered in atherosclerosis. Myocardial tissue from patients with coronary heart disease (CHD) or without CHD (control group) was investigated. The level of enzymes related to NO/ROS metabolism was determined both at mRNA level and protein level by rt-PCR, real-time PCR, and western blot. The expression of NOS1-3 (synthesis of NO), arginase1 (reduction of L-arginine), p22phox (active subunit of NADPH oxidase), GTPCH (rate limiting enzyme for tetrahydrobiopterin), SOD1-3 (scavengers of superoxide anions), PRTMT1-3, and DDAH2 (involved in the metabolism of ADMA) was determined. All enzymes were found to be expressed in human myocardium. NOS isoforms were decreased in CHD in protein level, but only the downregulation of NOS3 expression reached statistical significance. The expression of PRMT1 and PRMT3 was increased. In addition, the expression of DDAH2 was reduced, both theoretically leading to an increase of ADMA concentration. SOD3 was downregulated in tissue from patients with CHD. Taken together, in myocardial tissue from patients with atherosclerosis, the expression of genes increasing ADMA levels is enhanced in contrast to a reduced expression of genes promoting NO synthesis. These results may contribute to the explanation of increased oxidative stress in atherosclerosis on the level of gene expression.     

Sepiapterin reduces postischemic injury in the rat heart

A reduced availability of tetrahydrobiopterin (BH4), an essential cofactor for NO-synthesis, is causally involved in the development of endothelial dysfunction associated with ischemia/reperfusion. We, therefore, investigated the effect of sepiapterin, a substrate for BH4 synthesis, on postischemic injury in myocardial infarction and myocardial stunning. In rats, myocardial stunning was induced by repetitive ischemia (5×10-min ligature of the left coronary artery, 5×20-min reperfusion) and myocardial infarction by 50-min ligature and 60-min reperfusion. Myocardial blood flow was determined by H₂-clearance, regional myocardial function by pulsed Doppler and infarct size by tetrazolium staining. Myeloperoxidase (MPO) activity was measured as a marker of neutrophil extravasation. cGMP was determined in rat serum as an indicator of increased NO synthesis. In animals treated with sepiapterin, regional myocardial function was significantly improved in both myocardial stunning and infarction and infarct size was significantly reduced. MPO activity decreased with sepiapterin treatment in both models. The systemic level of cGMP was reduced both following myocardial stunning and myocardial infarction in the control group. Pretreatment with sepiapterin induced a significant increase of cGMP level at the end of the protocol in both models. Substitution of sepiapterin reduces postischemic injury both in myocardial stunning and infarction apparently by ameliorating the availability of NO, thereby attenuating the activation of neutrophils in ischemia/reperfusion.     

Sublingual versus vaginal misoprostol for second trimester termination: a randomized clinical trial

Purposes

To evaluate the efficacy of two routes of administration of misoprostol (sublingual and vaginal) for medical termination of second trimester pregnancies.

Methods

One hundred and thirty-four women referred for second trimester termination were enrolled in this randomized clinical trial. They were divided to receive 400 μg every 6 h misoprostol either sublingually or vaginally. They were followed for 48 h, at which point they underwent D&C if the termination was not complete. Efficacy was defined as successful termination without the need for interventions.

Results

There were no differences between the vaginal and sublingual groups in terms of tablets mean dose of misoprostol applied (1360 ± 2.4 vs. 1320 ± 2.3) or endometrial thickness after termination of pregnancy (13.02 ± 5.2 vs. 13.3 ± 6.6 mm). The success rate was 61.2 % (n = 41) in the vaginal group versus 70.1 % (n = 47) in the sublingual group (p = 0.3). Twenty-six patients (38.8 %) in the vaginal group underwent D&C due to retained tissue, compared with 20 patients (29.8 %) in the sublingual group. In primigravids, the success rate was significantly higher in the sublingual group than vaginal group. There was no significant difference with regards to complications between the two groups.

Conclusion

The sublingual route of misoprostol administration has the same efficacy as the vaginal route and can be applied for second trimester pregnancy termination in primigravid women in outpatient settings due to its simple administrations.     

Treatment of a patient with epidermodysplasia verruciformis carrying a novel EVER2 mutation with imiquimod

Epidermodysplasia verruciformis (EV) is a rare disorder characterized by widespread human papillomavirus infection and malignant transformation. EV may be caused by mutations of the genes EVER1 or EVER2, which are located on the EV1 locus, 17q25. We describe a patient with EV and a novel homozygous gene mutation of EVER2 gene who was treated successfully with topical imiquimod.     

Competition for Gβγ dimers mediates a specific cross-talk between stimulatory and inhibitory G protein α subunits of the adenylyl cyclase in cardiomyocytes

Heterotrimeric G proteins are key regulators of signaling pathways in mammalian cells. Beyond G protein-coupled receptors, the amount and mutual ratio of specific G protein α, β, and γ subunits determine the G protein signaling. However, little is known about mechanisms that regulate the concentration and composition of G protein subunits at the plasma membrane. Here, we show a novel cross-talk between stimulatory and inhibitory G protein α subunits (Gα) that is mediated by G protein βγ dimers and controls the abundance of specific Gα subunits at the plasma membrane. Firstly, we observed in heart tissue from constitutively Gαi2- and Gαi3-deficient mice that the loss of Gαi2 and Gαi3 was accompanied by a slight increase in the protein content of the nontargeted Gαi isoform. Therefore, we analyzed whether overexpression of selected Gα subunits conversely impairs endogenous G protein α and β subunit levels in cardiomyocytes. Integration of overexpressed Gαi2 subunits into heterotrimeric G proteins was verified by co-immunoprecipitation. Adenoviral expression of increasing amounts of Gαi2 led to a reduction of Gαi3 (up to 90 %) and Gαs (up to 75 %) protein levels. Likewise, increasing amounts of adenovirally expressed Gαs resulted in a linear 75 % decrease in both Gαi2 and Gαi3 protein levels. In contrast, overexpression of either Gαi or Gαs isoform did not influence the amount of Gαo and Gαq, both of which are not involved in the regulation of adenylyl cyclase activity. The mRNA expression of the disappearing endogenous Gα subunits was not affected, indicating a posttranslational mechanism. Interestingly, the amount of endogenous G protein βγ dimers was not altered by any Gα overexpression. However, the increase of Gβγ level by adenoviral expression prevented the loss of endogenous Gαs and Gαi3 in Gαi2 overexpressing cardiomyocytes. Thus, our results provide evidence for a novel mechanism cross-regulating adenylyl cyclase-modulating Gαi isoforms and Gαs proteins. The Gα subunits apparently compete for a limited amount of Gβγ dimers, which are required for G protein heterotrimer formation at the plasma membrane.