Evaluation of four elastomeric interocclusal recording materials

Background: The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semiadjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator.     

Conformationally constrained congeners of 6-aryl-5-methyl-4,5-dihydro-3(2H)-pyridazinones active on the cardiovascular system: conformational studies by molecular mechanics calculations and 1H NMR spectroscopy

Unsubstituted phenylpyridazinones 1a and 2a and their tricyclic analogues indenopyridazinone 3a, benzocinnolinone 4a, and benzocycloheptapyridazinone 5a were submitted to conformational analysis with Allinger's MM2(85) program in order to better define the relationship between the cardiovascular properties of some derivatives and their preferred conformations. Structures 1-4, giving rise to highly active compounds, were found to exist in a conformation showing a near-planar arrangement of the phenyl and the pyridazinone ring. On the contrary, 5, whose derivatives were inactive, shows two significantly populated conformations both markedly deviated from planarity. 1H NMR analysis of the tricyclic systems 3-5 was in full agreement with the molecular mechanics calculations.     

Quality of life assessment and HIV infection: A review

In the last few years, survival of patients infected with human immunodeficiency virus (HIV) has been improved because of a decreased incidence of some opportunistic complications attributable to prophylactic treatments and antiretroviral drugs. The impact of these agents should also be reflected in the quality of life (QoL) of patients. We have reviewed this topic with an emphasis on different types of measurements such as Q-TWIST, MOS and the Spitzer score which seem to be most appropriate for this patient population. We do not think that a special type of assessment should be designed for HIV-infected persons. It would be less time-consuming to improve already existing validated scores focusing on HIV infection. QoL in intravenous drug users with HIV should be evaluated more often.     

Effect of prostaglandin E1 on graft function of kidneys from living related donors

Prostaglandin E₁ (PGE₁) was used in renal transplant recipients with living related donors. The drug was given intravenously from day 1 to day 7 after transplantation at a dose of 40 µg/kg twice a day. A total of 45 patients were studied divided into two groups: 25 patients were treated with PGE₁ (group B) and the remaining 20 patients did not receive the drug (group A). In group B, 24-h creatinine clearance (Ccr) was 66 ± 12.8 ml/min compared with 40.3 ± 13.4 ml/min in group A on the fifth postoperative day (P < 0.05). Urinary levels of N-acetyl-β-d -glucosaminidase (NAG) and serum levels of platelet factor 4 (PF4) in group B were significantly lower than in group A. On the fourth postoperative day, the urinary excretion of thromboxan B₂ (TxB₂) in group A was higher than in group B, but not significantly (5.1 ± 3.0 ng/day and 2.8 ± 1.1 ng/day, respectively). Acute rejection occurred in four patients in group B and in 10 patients (40%) in group A. The percentage of Leu2a-positive lymphocytes in group B was higher than in group A. We conclude that postoperative administration of PGE₁ improves graft function in kidneys from living related donors.     

Inducible beta-lactamases in clinical isolates of non-aeruginosa Pseudomonas.

The incidence of antimicrobial resistance and expression of imipenem-inducible beta-lactamase were examined in 22 strains of non-aeruginosa Pseudomonas isolated from clinical specimens. The percentage of strains resistant to form one to eight antibiotics was 45. The most active antibiotics against all strains were norfloxacin, ciprofloxacin and imipenem. Eighteen out of the 22 strains were positive for beta-lactamase in a spectrophotometric assay using nitrocefin as substrate. A low inducible beta-lactamase specific activity (0.001-0.999 nmoles nitrocefin hydrolyzed/min/mg protein) was found in twelve strains whereas six strains had a relatively high specific activity (3.5-159.8 nmoles nitrocefin hydrolyzed/min/mg protein). Five strains representing different Pseudomonas spp. and showing high beta-lactamase activity were studied further. Crude enzymes from two species (Pseudomonas mendocina, Pseudomonas acidovorans) hydrolyzed cefazolin at a higher rate than penicillin and ampicillin. All enzymes from the five species were inhibited by cloxacillin and p-chloromercuribenzoate (1 mM), but were insensitive to inhibition by clavulanic acid, ethylenediamine acetic acid (EDTA) at the same concentration. The isoelectric point and molecular weight of the main beta-lactamase band from the 5 species were 6.5-6.8 and 47,000 respectively.