[Calcium antagonists and ischemic heart disease]

The authors give a short account about the significance, basic rules in regulation of intracellular (cytosolic) calcium homeostasis, distribution of calcium channels in different organs and characteristics of L channels in cardiovascular system. The different types of calcium channel blockers (dihydropyridines, phenylalkilamines, benzothiazepines), their similarities, dissimilarities (cardio, -vascular selectivity) are discussed. Differences in calcium homeostasis, in sympathetic innervation between vascular smooth- and heart muscle in briefly disputed. The basic role of endothel cell dysfunction in development of ischemic heart disease, the possible mechanisms (potential anti-remodeling, antifissuring, antiischemic, cardioprotective, sympaticolytic effects) of different calcium antagonists in the treatment of patients with ischemic heart disease are reviewed. Potential adverse effects of calcium channel blockers (proischemic, proarrhythmic, procongestive, prohaemorrhagic effects) are also mentioned. Finally the up-date preventive and therapeutic indications of different calcium channel blockers in the clinical management of patients with stable, unstable angina pectoris, silent myocardial ischemia, vasospastic angina, acute myocardial infarction is shortly reported.

Ipriflavone, an antiostheophorotic agent

The antiostheophorotic agent ipriflavone [7-(1-methyl-ethoxy)-3-phenyl-4H-1-benzopyran-4-one, C18H16O3] is an important member of the isoflavone family. The structure of the molecule is dominated by the dihedral angle (50 degrees) between the planes of the phenyl and benzo-pyran moieties. A structural comparison with other related published structures is represented.

Biphasic effect of prostaglandin E1 on the severity of acute pancreatitis induced by a closed duodenal loop in rats

The effect of prostaglandin E1 (PGE1) on the severity of acute pancreatitis induced by a closed duodenal loop in the rat was tested. PGE1 was administered subcutaneously at various doses (3, 6, 12, and 24 microgram/kg) at hourly intervals, from the induction of acute pancreatitis up to the 24th hour. A saline-treated group served as the control. The mortality rate was recorded, and pancreatic histology was evaluated by a scoring system. Serum amylase activity and pancreatic amylase, trypsin, protein, and desoxyribonucleic acid (DNA) contents were determined at 24 h. Administration of PGE1 influenced the severity of acute pancreatitis biphasically. Serum amylase was reduced significantly (p < 0.01) at a dose of 12 microgram/kg/h, but less at 24 microgram/kg/h. Pancreatic weights did not differ in the groups. Pancreatic amylase, trypsin, and protein contents showed significant elevations (p < 0.01), yet the mortality rate was reduced using 6 and 12 microgram/kg/h doses of PGE1 compared to controls, but not at higher and lower doses. The DNA content was significantly higher at the 6 microgram/kg/h dose, compared to the control. The extent of necrosis and the severity of hemorrhage were reduced significantly (p < 0.05) at doses of 6 and 12 microgram/kg/h of PGE1, but less at 24 microgram/kg/h. Leukocyte infiltration was not affected. In conclusion, optimal doses of PGE1 can ameliorate, but higher doses increase, the severity of acute pancreatitis in this experimental model.

Interesting conformational and substitutional disorder in the crystal structures of three homologous crowns

The structures of three members of a homologous family of diphenylamine-containing crowns, 2-chloro-6,7,9,10-tetrahydro-16H-dibenzo[b,k][1,4,7,10]monoazatrioxacyclododecine (NAI), 2-chloro-6,7,9,10,12,13-hexahydro-19H-dibenzo[b,n][1,4,7,10,13]monoazatetraoxacyclopentadecine (NAII), 2-chloro-6,7,9,10,12,13,15,16-octahydro-22H-dibenzo[b,q][1,4,7,10,13,16]monoazapentaoxacyclooctadecine] (NAIII), are reported, compared and trends are established. The largest crown (an 18-crown-6-type) presents an ability to form a molecular compound with water molecules spontaneously. The propeller-like conformational behaviour of the two phenyl rings leads to the presence of two chiral conformers in the unit cell of the crystals. Additionally, due to the conformationally non-equivalent role of the two phenyl rings, the chlorine substitution leads to two further species, resulting in four different conformers in each crystal structure. The presence of so many species in one crystal generates an interesting type of disorder in two of the three cases.

Anaphylactic shock during hysteroscopy using Hyskon solution: case report and review of adverse reactions and their treatment

Dextran 70 (Hyskon) solution, as many other substances, is in current use as distension medium during hysteroscopy. The advantages of Hyskon solution are its nonconductivity and immiscibility with blood, allowing good visibility during operative hysteroscopy. Adverse reactions to Hyskon are mainly attributable to the drug's antigenic properties and include severe anaphylactic reactions and fatalities. We report a case of anaphylactic shock during hysteroscopy using Hyskon solution as the distension medium, review the adverse reactions of Hyskon and summarize the treatment modalities used to decrease the incidence of the rare but serious adverse reactions with its use.

Long-term assessment of interferon responses in the HIV+ and AIDS patients

Impairment of interferon (IFN) system in human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) became a basis for searching IFN responses to monitor the disease progression. For detailed investigations 16 HIV+/AIDS patients with at least 4 successively taken blood samples available for IFN determinations were selected. IFN responses were tested in two ways. Firstly, IFN level in plasma was measured. Secondly, capacity of IFN production by leukocytes was evaluated. The latter was determined in the whole blood assay, in which Newcastle disease virus (NDV) and phytohemagglutinin (PHA) were used as IFN-alpha and IFN-gamma inducers, respectively. The levels of IFN induced in whole blood leukocytes varied considerably in all individuals that had been tested. Nevertheless, two patterns of IFN responses were observed. In pattern I, patients had low levels of IFN in plasma and high levels of induced IFN-alpha and IFN-gamma. It was characteristic for 8 patients in good clinical condition. On the contrary, severe disease found in 2 patients was correlated with high levels of IFN in plasma and low levels of induced IFNs (pattern II). In 6 patients IFN responses were classified as intermediate pattern I/II suggesting transition from pattern I to pattern II. A variation of pattern I was found in the case of a patient defined as long-term survivor having relatively low levels of all IFN tested. The results suggested that interferon measurements reflected clinical condition of HIV+ patients showing not only past but also current immune changes.

Prooxidant and antioxidant hepatic factors in rats chronically fed an ethanol regimen and treated with an acute dose of lindane

While acute lindane treatment and chronic ethanol feeding to rats have been associated with hepatic oxidative stress, the possible roles of these stresses in the pathogenesis of hepatic lesions reported in acute lindane intoxication and in those observed in some models of chronic alcoholism have not been established. Our previous studies in rats chronically fed ethanol regimens and then treated with a single intraperitoneal (i.p.) dose of lindane (20 mg/kg) showed that while lindane per se was invariably associated with hepatic oxidative stress, chronic ethanol feeding only produced this stress when the dietary level of vitamin E was relatively low. Chronic ethanol pretreatment did not significantly affect the lindane-associated oxidative stress, and neither chronic ethanol feeding nor acute lindane, single or in combination, produced any histologic and biochemical evidence of liver damage. In the present experiment, the acute dose of lindane was increased to 40 mg/kg, and we have studied a larger number of prooxidant and antioxidant hepatic factors. Male Wistar rats (115.5 +/- 5.4 g) were fed ad lib for 11 weeks a calorically well-balanced and nutritionally adequate basal diet, or the same basal diet plus a 32% ethanol/25% sucrose solution, also ad lib, and were then injected i.p. with a single dose of lindane or with equivalent amounts of corn oil. The results indicated that acute lindane treatment to naive rats increased practically all the prooxidant hepatic factors examined (cytochromes P450 and b5, NADPH cytochrome c reductase, NADPH oxidase), as well as the generation of microsomal superoxide radical and thiobarbituric acid reactive substances of liver homogenates, but did not modify any of the antioxidant hepatic factors studied. Conversely, the chronic administration of ethanol alone did not significantly affect the prooxidant hepatic factors but reduced some of the antioxidants (i.e., the activities of GSH-Px and the contents of alpha-tocopherol and ubiquinols 9 and 10). Although chronic ethanol pretreatment further increased the superoxide generation induced by lindane per se, it did not increase but generally reduced the effects of lindane per se on the other prooxidant factors studied. Furthermore, although acute lindane administration to ethanol-pretreated rats was associated with decreases in GSH and catalase (not affected by ethanol or lindane treatment alone), it did not substantially modify the reducing effects of ethanol feeding per se on GSH-Px, alpha-tocopherol, and ubiquinols. Once again, neither chronic ethanol feeding nor lindane treatment, single or in combination, was associated with any evidence of liver damage.

Two antithrombotic quinazolone derivatives

The structures of two antithrombotic quinazolone derivatives, 1,2,3,5-tetrahydro-2-benzylimidazo[5,1-b]-quinazolin-5-one, (I), and 3-benzyl-2-[1-(2,5-xylidino)-ethyl]quinazolin-4(3H)-one, (II), display significant differences in the bond lengths in one region of the quinazolone moiety.

A new diagnostic approach to congenital stridor using a laryngeal mask airway and rigid endoscope

Neonates with symptoms of stridor from birth, present a difficult diagnostic problem. We have demonstrated that by the use of a laryngeal mask airway in an anaesthetized baby breathing spontaneously, we are able to reach a diagnosis. This is accomplished by the introduction of a rigid fibre-optic endoscope through a Portex swivel connector and visualizing the glottis and larynx.

The natural history of postischemic T-wave inversion: a predictor of poor short-term prognosis?

BACKGROUND

This study followed up the natural history of T-wave inversion and assessed the short-term prognosis associated with the condition.

METHODS

Forty patients with acute ischemic syndrome, without infarction, and with postischemic T-wave inversion (group 1) were followed during the persistence (inverted T-wave period) and after the resolution of T-wave inversion (positive T-wave period). Another 40 patients with acute ischemic syndrome, without infarction and with normal T waves (group 2), were also followed.

RESULTS

Postischemic inverted T waves showed resolution within 3-21 days of presentation in 31 patients from group 1 on medical treatment alone. Further ischemic events (acute myocardial infarction, acute ischemic syndrome, angina pectoris, silent ischemia), inducible ischemia (during treadmill test), wall-motion abnormalities (demonstrated by echocardiography), all developing in the primarily ischemic myocardial area, were more frequent (P < 0.02) in group 1 patients during the inverted T-wave period compared with those experienced in the positive T-wave period of group 1 patients, and compared with group 2 patients.

CONCLUSION

In most patients on medical treatment, postischemic inverted T-waves tended to resolve within 3 weeks. The presence of postischemic inverted T waves appears to be an independent marker of further ischemic events.

[The place of fibronectin in hepatologic diagnosis]

In the paper the structure, place od synthesis and biological role of fibronectin in human organism are discussed, and the value of plasma fibronectin (FN) concentration determination in the diagnosis of chronic hepatic diseases, including hepatic fibrosis, was critically evaluated. Simultaneously, the view is presented that the determination of FN concentration in peritoneal fluid, as well the determination of amount and location of FN in the hepatic tissue should be a routine element of hepatological diagnosis.