Subcellular localization of prostaglandin endoperoxide H synthases-1 and -2 by immunoelectron microscopy

Prostaglandin endoperoxide H synthases-1 and -2 (PGHS-1 and -2) are the major targets of nonsteroidal anti-inflammatory drugs like aspirin and ibuprofen. These enzymes catalyze the committed step in the formation of prostanoids from arachidonic acid. Although PGHS-1 and -2 are similar biochemically, a number of studies suggest that PGHS-1 and PGHS-2 function independently to form prostanoids that subserve different cellular functions. We have hypothesized that these isozymes may reside, at least in part, in different subcellular compartments and that their compartmentation may affect their access to arachidonic acid and serve to separate the functions of the enzymes. To obtain high resolution data on the subcellular locations of PGHS-1 and -2, we employed immunoelectron microscopy with multiple antibodies specific to each isozyme. Both PGHS-1 and -2 were found on the lumenal surfaces of the endoplasmic reticulum (ER) and nuclear envelope of human monocytes, murine NIH 3T3 cells, and human umbilical vein endothelial cells. Within the nuclear envelope, PGHS-1 and -2 were present on both the inner and outer nuclear membranes and in similar proportions. Western blotting data showed a similar distribution of PGHS-1 and -2 in subcellular fractions, and product analysis using isozyme-specific inhibitors suggested that both enzymes generate the same products in NIH 3T3 cells. Thus, we are unable to attribute the independent functioning of PGHS-1 and PGHS-2 to differences in their subcellular locations. Instead, the independent operation of these isozymes may be attributable to subtle kinetic differences (e.g. negative allosteric regulation of PGHS-1 at low concentrations of arachidonate (500-1000 nM)). A further conclusion of importance from a cell biological perspective is that membrane proteins such as PGHS-1 and -2, which are located on the lumenal surface of the ER, are able to diffuse freely among the ER and the inner and outer membranes of the nuclear envelope.     

Hypertension in thoracic transplant recipients

There are many mechanisms underlying the hypertension which occurs after thoracic transplantation. Previous disease, effects of cyclosporin, tacrolimus and steroid immunosuppression and cardiac denervation are major contributory factors. Abnormal sodium and water balance is an important common mediating factor. A new approach is clearly needed for classifying the severity of hypertension in these patients taking into account day-night variation and total blood pressure (BP) load. This would allow improved strategies for investigation and treatment. The evidence suggests that ambulatory BP measurements should be included in the assessment of initial severity of post-transplant hypertension as well as response to treatment. Further studies are needed to look at the effects of raised clinic and 24-h ambulatory BP and its treatment on longer term morbidity and mortality in thoracic transplant patients.     

Action of pure ethanol and some alcoholic beverages on the gastric mucosa in healthy humans: a descriptive endoscopic study

A method for the simultaneous determination of residues of 17 beta-trenbolone and 17 beta, 19-nortestosterone and their epimers in animal tissues is described, involving immunoaffinity chromatography clean-up and high-performance liquid chromatography with dual-wavelength UV detection. The method has been validated at 2 micrograms/kg in pig and cattle liver and corned beef with recoveries of 41% upwards. The method has been applied to the determination of incurred residues of 19-nortestosterone and trenbolone. Various alternative extraction steps for incurred trenbolone have been investigated, including direct extraction, protease digestion, heating and ultrasonic probe treatment. Glucuronidase digestion has been shown to be the most effective method for this analyte.     

Utility of low mA 1.5 pitch helical versus conventional high mA abdominal CT

We treated nine patients of mycoplasmal pneumonia with sparfloxacin (SPFX) the clinical efficacy, safety and usefulness of SPFX were evaluated. SPFX was administered orally at doses of 200 or 300 mg once daily, and we performed bronchoalveolar lavage (BAL) examinations in five patients. BAL was performed 5 hours after oral administration of 100 mg in one case, 19 hours after oral administration of 200 mg in four cases. Concentrations of SPFX and alubumine were measured in serum and in BALF (bronchoalveolar lavage fluid). The following results were obtained. 1. Nine patients were evaluated; eight patients judged as Good, one patient as Excellent. 2. The serum and BALF levels of SPFX was 0.79 microgram/ml, 0.107 microgram/ml 5 hours after single oral administration of 100 mg in one case and 19 hours after oral administration of 200 mg in four cases, those of levels of SPFX were 0.835 +/- 0.274 microgram/ml and 0.081 +/- 0.033 microgram/ml, respectively. 3. The ratio of SPFX/albumin in BALF was significantly higher than in the serum. From these results, we consider that SPFX is a useful antimicrobial agent for mycoplasmal pneumonia.     

RNA quantitation by fluorescence-based solution assay: RiboGreen reagent characterization

The safety, toxicity, and pharmacokinetics of intrapartum and early newborn nevirapine were evaluated in 17 human immunodeficiency virus type 1-infected women in labor and their newborns. No adverse effects of nevirapine were noted in any study mothers or infants. Following maternal dosing with 200 mg during labor, concentrations exceeding 100 ng/mL (10 times the in vitro IC50) were achieved in the newborns. Nevirapine elimination was prolonged in both mothers and infants, with median half-lives ranging from 36.8 to 65.7 h. Administration of 200 mg orally to the mothers in labor and of a single 2-mg/kg oral dose to the infants at 48-72 h after birth maintained serum concentrations in the infants > 100 ng/mL through 7 days of life.     

Patch migration: a serious late complication of thoracotomy lead systems

Thoracotomy patch leads used for implantable cardioverter defibrillators (ICDs) are generally safe and effective. We describe two patients in whom a late complication of patch lead migration occurred years after the original implants, causing a bronchopleural fistula in one and lingular lobe collapse in the other patient. We conclude that patch migration is a late but possible complication of extrapericardial ICD leads, and should be suspected in patients who present with hemoptysis, atypical pneumonia, or lung collapse after the initial ICD surgery.     

Microlens lithography: A new approach for large display fabrication

Microlens lithography is a new lithographic method, that uses microlens arrays to image a lithographic mask onto a substrate layer. Microlens lithography provides photolithography at a moderate resolution for an almost unlimited area. The imaging system consists of stacked microlens arrays forming an array of micro-objectives. Each micro-objective images a small part of the mask pattern, the images overlap in the image plane. Potential applications for microlens lithography are the fabrication of large area flat panel displays (FPD), color filters, and micromechanics.