Anti-atherogenic drugs

Rupture of an instable plaque, characterized by a large lipid-rich central core, inflammatory cells, and a thin fibrous cap, causes sudden thrombus formation and acute coronary syndromes (ACS). Lipid lowering therapy by HMG-CoA reductase inhibitors leads to reduction of cardiovascular complications, but has very small effect on the degree of stenosis of ACS. Oxidizing metabolites generated at the site of coronary angioplasty can induce chain reactions that may lead to restenosis. Probucol improves the restenosis rate after coronary angioplasty if given before PTCA (percutaneous transluminal coronary angioplasty). These results will provide a better understanding of drug action, help explain certain drug interactions, and facilitate the choice of a drug for ACS.     

Gastrointestinal drugs

The cutaneous glands of the forehead and the metatarsus were studied by histological and histochemical methods and electron microscopy in adult male and female impalas in various seasons of the year. All glandular areas consist of apocrine and holocrine glands, which, however, occur in different proportions. Our findings in the apocrine gland cells suggest (1) the synthesis and exocytosis of a glycoproteinaceous secretory product stored in secretory granules, (2) typical apocrine secretion of the transformed apical cytoplasm, and (3) transepithelial fluid transport. The Golgi apparatus and apical membrane have binding sites for several lectins (PNA, HPA, RCA I, WGA). Cytokeratins 7, 14 and 19 are expressed at various intracellular localizations, suggesting an active role in the secretory mechanisms. The glands of the male forehead show marked seasonal changes in activity that are correlated with the main phases of the reproductive cycle, with the highest cellular activity occurring during the rut in April/May. The female forehead glands are only moderately developed and do not undergo seasonal changes. The metatarsal glands are of equal size in males and females and show no seasonal changes in activity. This study supports the hypothesis that (1) forehead glands in the male have a signaling role in the rut and (2) the metatarsal glands have a more general, probably social role maintaining and restoring contact between herd members.     

Poisoning with anti-hypertensive drugs: beta-adrenoceptor blocker drugs

The effects of poisoning with beta-blockers may be serious, but are usually self-limiting provided adequate support is given. If there is no evidence of toxicity and the degree of overdose is small, clinical observation may be all that is required. This review examines the cases of overdosage with beta-blockers reported in the literature, the presenting symptoms and possible strategems of management for such patients.     

Hemostatic drugs

Recent research has investigated drug combinations that enhance the analgesic effectiveness of their component substances. Many studies have examined the combination of opioids and psychostimulant drugs, such as amphetamine and methylphenidate. Despite the positive results reported in the literature, this combination is rarely used in clinical practice. The purpose of this paper is to review the literature on the opioid-amphetamine combination. Experiments with animal and human subjects provide convincing evidence that d-amphetamine or methylphenidate potentiate the analgesic effects of morphine. Psychostimulant drugs have been shown in animal studies to possess intrinsic analgesic properties and to have the ability to enhance the analgesic properties of opioids when both types of drugs are given in combination. Studies with human subjects have confirmed the enhancement of opioid analgesia by amphetamines and, in addition, have demonstrated that psychostimulant drugs produce a decrease in somnolence and an increase in general cognitive abilities. The greater cognitive alertness, moreover, allows the use of larger opioid doses, which can produce a substantial increase in analgesia. These results indicate another possible method to enhance the quality of life in patients with difficult pain problems. Although the enhanced cognitive effects are well established, the effects on pain need further study to determine the mechanisms of action and the drug combinations and administration patterns that would maximize their effects.     

Anti-obesity drugs

In patients with hematological malignancies invasive mycoses occur frequently. In this retrospective study autopsy and histopathology material of 171 patients with hematological malignancy who had died between 1994 and 1996 at the 1st Department of Internal Medicine (Hematology), St. László Hospital, Budapest was analysed. In cases with invasive fungal infection post mortem results were compared to clinical and microbiological data. Through the three years' period an invasive mycosis could be confirmed in 33 patients by autopsy. Aspergillosis occurred in 21, candidiasis in 11, other fungal infections in 2 cases, a double infection was seen in 1 patient. The incidence was 19.2% (in invasive candidiasis: 6.4%, in aspergillosis 12.2%). Invasive aspergillosis most frequently was seen in the lung (71%), while candidiasis occurred mainly in the intestinal tract (42%). Cultures for mycology were collected from the autopsy material of 9 patients, of which 8 gave positive results. A previous fungal colonisation results was confirmed in 23 patients, but based on colonisation conclusions rarely could be driven concerning the species causing invasive infection. Sensitivity of Aspergillus antigen and antibody tests was 45 and 50%, respectively. Predisposing factors for invasive aspergillosis and candidiasis were similar, except for duration of neutropenia (24 vs. 12 days, p < 0.004). The antifungal drug most frequently used was amphotericin B. We observed a persisting infection in invasive pulmonary aspergillosis and chronic disseminated candidiasis in spite of the administration of a cumulative dosis of 1-2 g. Most frequently Aspergillus infections--primarily that of the lung--can be seen. Presence of invasive mycoses can usually be confirmed in vivo, but an early diagnosis still remains unsolved.     

New lipid lowering drugs and new effects of old drugs

Old lipid acting drugs (fibrates, resins and niacin) continue to demonstrate morbidity and mortality benefits with variable efficacy and safety. Controlled trials have provided efficacy and safety data that support the use of statins as the first choice in the treatment and prevention of atherosclerosis. Knowledge of old and new mechanisms of action, optimal doses, pharmacokinetic behavior and drug interactions improve the safety and effectiveness of these hypolipidemic agents.     

Ototoxicity of drugs

The paper included the most current information about the mechanisms of ototoxicity of five groups of the most popular drugs: a) antibiotics, b) chemotherapeutics (cytostatic) agents, c) loop diuretics, d) salicylate and nonsteroidal anti-inflammatory drugs, as well as e) progestagen contraceptives minimized or even prevented by thoughtful selection of drug, attention to risk factors and careful patient monitoring.     

Newer antihypertensive drugs

We review three new classes of antihypertensive drugs: imidazolines, monatepil, and neutral endopeptidase inhibitors. Imidazolines are a new generation of central acting drugs. Because of their greater affinity for imidazoline receptors rather than alpha 2-adrenoreceptors, they cause less fatigue and dry mouth than the older central acting drugs. Monatepil is a single drug with both calcium antagonist and peripheral alpha 1-antagonist properties. This agent not only lowers blood pressure but also lowers serum cholesterol, an effect mediated by its alpha-antagonism, and has anti-lipid peroxidation properties. Monatepil might become an effective antiatherosclerosis drug. Neutral endopeptidase inhibitors lower blood pressure by inhibiting the metabolism of atrial natriuretic peptide and other vasoactive peptides.     

New antiepileptic drugs

No fewer than eight new antiepileptic drugs (AEDs) with diverse mechanisms of action have been introduced into clinical practice in the 1990s. Short monographs on lamotrigine, vigabatrin, gabapentin, oxcarbazepine, felbamate, topiramate and vigabatrin have been prepared for this review. Details are provided of mechanisms of action, clinical pharmacokinetics and adverse drug interactions. Each section concentrates on the efficacy, tolerability and practical use of these drugs. The areas where they have potential for superiority over the established AEDs have been highlighted. Specific indications and dosage schedules have been provided. As many of these AEDs have, as yet, limited licences, an attempt has been made to identify ongoing studies and important omissions. Where possible, the eventual place of the new agent in the pharmacological management of epilepsy has been assessed. A more limited summary has been included of zonisamide which, although licensed in Japan, is still regarded as an investigational drug elsewhere. Short discussions of three of the most promising investigational compounds, namely remacemide, losigamone and levetiracetam, complete the picture.     

New antiepileptic drugs

Survival of Escherichia coli O157:H7 strains QA 326, and ATCC 43889, 43894, and 43895 after freezing (-20 degrees C, 24 h) and thawing (4 degrees C for 12 h, 23 degrees C for 3 h, or microwave heating of 700 W for 120 s) in ground beef patties was determined by reference most probable number (MPN), hydrophobic grid membrane filter SD-39 agar, and sorbitol MacConkey agar (SMA) spread-plating methods. Populations decreased from 0.62 to 2.52 log10 CFU/g, with the extent varying significantly by strain. Strain QA 326 populations almost always decreased the most, up to 1.87 log10 CFU/g more than the least sensitive strain. Microwave heating was the most lethal thawing treatment for strain QA 326, and 4 degrees C thawing was the most lethal treatment for strain ATCC 43894. Thawing treatments varied in relative lethality for the other two strains. For strain QA 326 (4 degrees C and microwave thaw treatments) and strain ATCC 43889 (4 and 23 degrees C thawing), the enumeration method significantly affected a population decrease. The SD-39 agar method best recovered strain QA 326 while the SD-39 agar method and the reference MPN method best recovered strain ATCC 43889 after 4 and 23 degrees C thawing, respectively. The greatest difference in population decrease measured by any two methods was 0.58 log10 CFU/g. Results showed (i) a wide range in freeze-thaw sensitivity among E. coli O157:H7 strains, (ii) no thawing method had consistently and significantly greater lethality, and (iii) the reference MPN, SD-39 agar, and SMA methods differed little in ability to enumerate E. coli O157:H7.     

Main cardiotoxic drugs

The potential to increase passive serum antibody titres to a polysaccharide antigen in neonates, by preparturient vaccination of the dams was investigated. Dairy cows in five private herds were vaccinated with a commercial Pasteurella haemolytica culture supernatant vaccine (Presponse, Langford Inc.), at 6 and 3 weeks before their calculated due dates. Dams' sera, colostral whey, and post-colostral calf sera were assayed for antibodies of the IgG1 isotype binding purified capsular polysaccharide of P. haemolytica A1, using an enzyme immunoassay. Antibody titres were analyzed using the General Linear Model procedure (Statistical Analysis Systems Institute Inc.). Vaccinated dams had a significant increase in serum antibody titre after vaccination compared with non-vaccinates (P <0.01), and their antibody titres in colostral whey were significantly higher (P <0.05). Calves of vaccinated dams had significantly higher passive antibody titres than those of non-vaccinates (P <0.01) in all herds.     

Current antimicrobial drugs

In the past few years several new antibiotics became available, but no major inventions as to new treatment strategies were made. There are a few new broad-spectrum antibiotics for the intravenous route like piperacillin-tazobactam, the carbapenem meropenem and the fourth-generation cephalosporins. cefepime and cefpirome. New oral antibiotics include the third-generation cephalosporins ceftibuten, cefetamet and cefpodoxime and the macrolides clarithromycin and azithromycin. The last two have the great advantage of less frequent dosing and fewer side effects than erythromycin. Of the two new quinolones, sparfloxacin and trovafloxacin, trovafloxacin is the more promising. In the treatment of Gram-positive infections the glycopeptide teicoplanin became available and the combined derivatives quinupristin-dalfopristin may prove valuable in the future.     

Antibody-targeted polymer-bound drugs

Drug targeting is an attractive new approach to killing cancer cells while leaving normal tissue unharmed. Recently we have developed a new generation of antibody-targeted immunosuppressive (cyclosporin A) and cytostatic (daunomycin, doxorubicin) drugs and photosensitizers (chlorin e6) effective in vitro and in vivo. The drugs and the targeting antibody (polyclonal and monoclonal) are conjugated to the oligopeptidic side chains of a water-soluble synthetic carrier, copolymer of N-(2-hydroxypropyl)methacrylamide. The composition of the side chains ensures the stability of the linkage between the drug and the polymeric carrier in the bloodstream and its intralysosomal degradability which is a prerequisite for the pharmacological activity of the preparation. Antibody-targeted polymer bound drugs show considerably decreased hepatotoxicity, cardiotoxicity, myelotoxicity and nephrotoxicity. Two adriamycin-HPMA copolymers are in Phase I/II clinical trials in United Kingdom.