Comparative studies of antiplatelet activity of nonsteroidal antiinflammatory drugs and new pyrazine CH- and NH-acids

General analytical procedure for determination of acidity parameters of weak acids and bases

The paper presents a new convenient, inexpensive, and reagent-saving general methodology for the determination of pK a values for components of the mixture of diverse chemical classes weak organic acids and bases in water solution, without the need to separate individual analytes. The data obtained from simple pH-metric microtitrations are numerically processed into reliable pK a values for each component of the mixture. Excellent agreement has been obtained between the determined pK a values and the reference literature data for compounds studied.

Management of acute postoperative hemorrhage in the bariatric patient

Bariatric surgery is one of the treatment options for achieving and preserving weight loss and managing medical complications related to obesity. After bariatric surgery, early or late adverse events, such as intraluminal or extraluminal gastrointestinal hemorrhage, can occur. Early gastrointestinal bleeding is more often a complication associated with Roux-en-Y gastric bypass surgery than other bariatric procedures and usually arises from the gastrojejunal anastomosis. Early postoperative bleeding may be potentially life threatening, although death after postbariatric surgery as a consequence of acute bleeding is uncommon. Although early postoperative intraluminal bleeding can usually be managed conservatively, endoscopic therapy may be required.

2-(3-Chloro-1,2-dihydro-pyrazin-2-yl-idene)malononitrile

In the crystal structure of the title compound, C(7)H(3)ClN(4), neighbouring mol-ecules are linked via pairs of N-H⋯N hydrogen bonds into inversion dimers, thereby forming an R(2) (2)(12) ring motif. With respective average deviations from planarity of 0.009 (1) and 0.006 (1) Å, the pyrazine skeleton and the malononitrile fragment are oriented at an angle of 6.0 (1)° with respect to each other. The mean planes of the pyrazine ring lie either parallel or are inclined at an angle of 68.5 (1)° in the crystal structure.

Synthesis and hypolipidemic and antiplatelet activities of alpha-asarone isomers in humans (in vitro), mice (in vivo), and rats (in vivo)

A series of alpha-asarone isomers was synthesized and investigated for their hypolipidemic and antiplatelet activity. Considering the hypolipidemic activity in rats at a dose of 80 mg/kg/day, some isomers were more potent than clofibrate at 150 mg/kg. Compound 3 was one of the most active agents elevating the HDL cholesterol level by 56% and lowering the LDL cholesterol level by 46.8% in rats after 7 days of administration. The activities of the platelet aggregation test in vitro were significant but lower than those of the reference substances (indomethacine and acetylsalicylic acid). In the pulmonary thromboembolic in vivo test in mice, two compounds (alpha-asarone (6) and compound 4) produced significant antithrombotic effects at 100 mg/kg, namely 44% and 52% protection against lung microembolia, respectively. alpha-Asarone derivatives form a new group of potential hypolipidemic and/or antithrombotic agents. The compounds 3, 4, and 6 may serve as lead substances whose structural modifications may result in original drugs.

6-(Hydroxyphenyl)imidazo[2,1-b]thiazoles as Potential Antiinflammatory Agents: Effects on Human Neutrophil Functions

Synthesis of 6-(hydroxyphenyl)imidazo[2,1-b]thiazoles related to levamisole from the corresponding methoxy derivatives is reported. These compounds were tested on in vitro neutrophil activation, namely locomotion induced by chemoattractants, superoxide generation and lysozyme degranulation triggered by agonists. These functions were evaluated after cell pulse with different concentrations of the drugs. Several derivatives showed significant inhibitory effects, in some cases more potent than the parent compound.

[Role of non-steroidal anti-inflammatory agents in the perioperative period. Usefulness and limitations]

Nonsteroidal antiinflammatory drugs (NSAIDs), including various chemical families of drugs, inhibit prostaglandin synthesis and act on the central nervous system. Prostaglandins are involved in regulation of regional circulations, cell turn-over in the gastrointestinal tract, and in primary haemostasis. The patterns of action of NSAIDs result in analgesic properties, but also in adverse effects. NSAIDs are increasingly used perioperatively, alone or associated with opioids or local anaesthetics, because of their analgesic and opioid sparing properties. Some of their adverse effects, especially ischaemic acute renal failure and gastrointestinal complications, can be life-threatening, and increased haemorrhagic risk is an issue for spinal or epidural anaesthesia in patients taking aspirin. Safe use of NSAIDs is possible in consideration of contraindications (elderly patient, hypovolaemia, cirrhosis, congestive heart failure, renal failure, active gastrointestinal ulcer, bleeding diathesis, pregnancy), and requires close monitoring of renal function if they must be used in patients at risk for renal failure. NSAIDs are not ulcerogenic in the short-term in healthy subjects. They must be used with caution in patients with a preexisting haemostatic defect or undergoing haemorrhagic surgical procedures.