Carcinogenic Potential of Gasoline and Diesel Engine Oils

Used gasoline engine oils are carcinogenic in mouse skin andmutagenic in Salmonella. The toxicity of fresh gasoline engineoils and that of fresh and used diesel engine oils are lesswell defined. The present studies examined the dermal carcinogenicpotential of a series of fresh and used oils from both gasolineand diesel engines. The used oils represented a variety of operatingconditions. The objective of the study was to assess the potentialcarcinogenic hazards associated with exposure to these materials.The majority of the used gasoline engine oils tested were carcinogenicalthough one oil, collected after a relatively short drainageinterval, was inactive in the dermal carcinogenesis bioassay.Additionally, polycyclic aromatic hydrocarbon (PAH) concentrationswere elevated in the used oils in comparison to the fresh oils.The fresh gasoline engine oils and both the fresh and used dieselengine oil samples were noncarcinogenic, and there was littleevidence of elevated PAH levels in the used diesel engine oils.The carcinogenic potency of used oils from gasoline engineswas related to drainage interval, but other factors such ascontribution of the fuel due to blowby and driving cycle mayalso have been important. The used diesel engine oils were notcarcinogenic even after extended use.     

Glucagon releasing activity of a cyclic peptide related to somatostatin

A possible benefit of creating smaller and more rigid active analogs of somatostatin is the discovery of compounds which selectively inhibit the secretion of insulin, glucagon or growth hormone. A series of cyclic tetrapeptide analogs related to somatostatin was synthesized, and one member of this series was found to cause an unexpected stimulation of glucagon secretion while having little if any effect on either insulin or growth hormone secretion. A sustained increase in plasma glucose levels was also observed. Two possible modes of action are proposed.     

Functional Assessment of Rabbit Alveolar Macrophages following Intermittent Inhalation Exposures to Sulfuric Acid Mist

Functional Assessment of Rabbit Alveolar Macrophages followingIntermittent Inhalation Exposures to Sulfuric Acid Mist. SCHLESINGER,R. B. (1987). Fundam. Appl. Toxicol. 8, 328–334. Sulfuricacid (H₂SO₄) aerosols are common in both ambient and occupationalenvironments. This study examined the numbers and selected invitro functional properties of alveolar macrophages recoveredfrom rabbits undergoing inhalation exposure to 0.5 mg/m³ submicrometer(0.3 µm) H₂SO₄ for 2 hr/day. Bronchoalveolar lavage wasperformed on Days 3, 7, and 14 during the exposure period (specifically,24 hr after either 2, 6, or 13 exposures). Total cell numbersand macrophage counts were increased on Day 3, but returnedto control levels by Day 7; no change in polymorphonuclear leukocyteswas observed at any time point. Macrophage substrate attachmentwas not affected by exposures to H₂SO₄, but random mobilitywas severely depressed at Days 7 and 14. The numbers of phagocyticallyactive macrophages and the level of such activity were increasedon Day 3, but became depressed by Day 14. These results demonstratesignificant alterations in important functional properties ofalveolar macrophages due to short-term intermittent exposuresto H₂SO₄ aerosols; these changes have implications for the abilityof the lungs to maintain adequate defense against depositedviable and nonviable particles.     

Solid phase peptide synthesis utilizing 9-fluorenylmethoxycarbonyl amino acids

9-Fluorenylmethoxycarbonyl (Fmoc) amino acids were first used for solid phase peptide synthesis a little more than a decade ago. Since that time, Fmoc solid phase peptide synthesis methodology has been greatly enhanced by the introduction of a variety of solid supports, linkages, and side chain protecting groups, as well as by increased understanding of solvation conditions. These advances have led to many impressive syntheses, such as those of biologically active and isotopically labeled peptides and small proteins. The great variety of conditions under which Fmoc solid phase peptide synthesis may be carried out represents a truly “orthogonal” scheme, and thus offers many unique opportunities for bioorganic chemistry.     

Phenytoin in the Treatment of Inducible Ventricular Tachycardia: Results of Electrophysiologic Testing and Long-Term FoUow-Up

Phenytoin treatment of inducible ventricular tachyarrhythmias was assessed by serial electrophysiologic studies (EPS) in 64 patients with spontaneous ventricular tachycardia, cardiac arrest, or symptoms compatible with a ventricular tachyarrhythmia. Coronary artery disease was the primary cardiac disease in 75% of the patients. All subjects had either inducible ventricular tachycardia (greater than or equal to 10 repetitive beats) or ventricular fibrillation at electrophysiologic study. Phenytoin was administered intravenously in 38 studies and orally in 31 studies. The mean serum phenytoin level was 19.5 +/- 4.7 mcg/ml. Only seven patients (11%) had a negative electrophysiologic study (less than or equal to 10 repetitive beats) after the administration of phenytoin and were classified as phenytoin responders (group I). The remaining 54 patients (89%) were classified as nonresponders (group II). For the nonresponders, phenytoin increased the cycle length of identical monomorphic ventricular tachycardias from a mean of 31 ms to a mean of 327 ms (p less than 0.001). For the four patients tested receiving both intravenous and oral phenytoin, the intravenous response always predicted the oral response. For the seven patients in whom electrophysiologic study indicated phenytoin efficacy, two are alive and arrhythmia-event free, two had sudden death when the regimen was changed (one case, quinidine added; one case, subtherapeutic serum level), and three died from nonarrhythmic causes. For the 10 patients treated empirically with phenytoin, either alone (seven patients) or in combination with another antiarrhythmic agent (three patients), four died secondary to an arrhythmic event.(ABSTRACT TRUNCATED AT 250 WORDS)     

STUDIES ON THE PHYSIOLOGY OF THE WHITE BLOOD CELL: THE GLYCOGEN CONTENT OF LEUKOCYTES IN LEUKEMIA AND POLYCYTHEMIA

The technic of determining glycogen in isolated white blood cells was appliedto the study of the different types of leukemia and of polycythemia, in order toobtain information on the physiology of the white blood cell. From this study itis concluded that the granulated leukocyte is the only carrier of glycogen in wholeblood. The "reducing substances" in lymphocytes and blast cells are not consideredas true glycogen.

The glycogen content of wet white blood cells in the rabbit amounts to about1 per cent. In the human being a range of from 0.17 to 0.67 per cent was calculated.In disease higher percentages occur, in polycythemia up to 1.64 per cent and inglycogen storage disease up to 3.05 per cent.

The glycogen concentration of normal white blood cells is within the same rangeas that of the striated muscle.

Note: I acknowledge with gratitude my indebtedness to Dr. William Dameshek for giving me the opportunity of analyzing the blood of some of the patients studied. Miss M. H. Campbell, Miss H. A. Clark,and Miss L. M. Garofalo have aided in carrying out many of the blood counts.

     

The essential drugs programme in Zimbabwe: new approaches to training

The Zimbabwe Essential Drugs Action Programme has developedan innovative approach to training within the overall programme.The programme depends on the active participation of rural healthstaff in the production of training materials, combined withdesk-top publishing technology. The modules thus produced havebeen used at provincial and district workshops. Such an approachto the production of training materials is applicable to subjectsother than essential drugs.     

Carotid Artery Percutaneous Transluminal Angioplasty and Stenting: Indications, Technical Approach, and Complications

Carotid percutaneous transluminal angioplasty and stenting are relatively new tools in the field of vascular therapeutics. They are products of the evolution of the techniques used in the therapy of coronary and peripheral vascular disease. Carotid endarterectomy is still the "criterion standard" to which all other carotid interventions are compared. This status has been achieved on the basis of extensive studies on symptomatic and asymptomatic patients. For carotid percutaneous transluminal angioplasty and stenting to become a proven alternative for the therapy of carotid disease, their precise use and role still need to be defined by randomized prospective trials. If performed by experienced operators with meticulous technique, the risk of complications is very low. Outpatient-based 1-day hospitalization, well tolerated, and avoiding anesthesia related complications make their future in the therapy of carotid disease very optimistic.