Double J stent of frontal sinus outflow tract in revision frontal sinus surgery.

OBJECTIVE: Frontal sinus surgery continues to challenge even the most experienced endoscopic sinus surgeon. Revision frontal sinus surgery is even more challenging. The use of stents in frontal sinus surgery has long been described, as an attempt to decrease the incidence of synechiae and stenosis. METHOD: This study included five patients who had previously undergone functional endoscopic sinus surgery but suffered recurrence of frontal sinusitis. Two had bilateral disease. Double J stents were used after endoscopic frontal sinusotomy. The stents were left in place for six months. RESULTS: Four of the 5 patients (6 out of 7 sinuses) had a patent frontal outflow tract after 10 to 36 months' follow up. CONCLUSION: Double J stents can be used as frontal sinus stents. They are well tolerated by patients, easily applied, and self-retaining with no need for sutures. The length of the stent can be altered according to the patient's anatomy and pathology.

Comparing ethylene glycol with glycerol for cryopreservation of buffalo bull semen in egg-yolk containing extenders.

The objective of this work was to evaluate the possibility of substituting glycerol for ethylene glycol when cryopreserving buffalo semen. Semen of eight buffalo bulls was mixed, pooled, and frozen in one of these four diluents: centrifuged Tris egg yolk glycerol; centrifuged Tris egg yolk ethylene glycol; centrifuged Milk egg yolk glycerol; or centrifuged Milk egg yolk ethylene glycol. Semen quality parameters assessed after thawing were motility, survivability, livability, sperm abnormality, acrosome integrity, and plasma membrane integrity. Conception rate and pregnancy rate were calculated after insemination of 104 buffaloes by straws of different groups (26 female/extender). Improvement in livability, sperm abnormality, acrosome integrity, plasma membrane integrity, conception rate, and pregnancy rate were seen when using ethylene glycol to replace glycerol when freezing buffalo bull semen in centrifuged TRIS egg yolk 61.15 ± 0.73, 24.85 ± 0.41, 69.10 ± 0.81, 71.75 ± 0.72, 46.2%, and 46.2%, respectively, followed by centrifuged milk egg yolk extenders.

Effect of some hypoglycemic herbs on the activity of phase I and II drug-metabolizing enzymes in alloxan-induced diabetic rats.

Polycyclic aromatic hydrocarbons (PAHs) and N-nitrosamines (NNA) are mainly activated by cytochrome P450s, and their associated enzyme activities such as aryl hydrocarbon (benzo(a)pyrene) hydroxylase (AHH), N-nitrosdimethylamine N-demethylase I (NDMA-dI), NADPH-cytochrome C reductase, and detoxified by glutathione S-transferase (GST) and glutathione (GSH). The present study shows the influence of Cymbopogon proximus (Halfa barr), Zygophyllum coccineum L. (Kammun quaramany), Lupinus albus (Termis) as herbs capable of inducing hypoglycemia on the activity of the above mentioned enzymes in the liver of diabetic rats. Alloxan was administered as a single dose (120 mg/kg body weight) to induce diabetes and the herbs were administered to diabetic rats as repeated doses for 4 weeks. Alloxan-induced diabetes significantly increased the blood glucose level by 93% compared to the control level. On the other hand, repeated-dose treatments of diabetic rats with Cymbopogon proximus and Lupinus albus are more effective than Zygophyllum coccineum in restoring the elevated blood glucose level to the normal level. Alloxan treatment increased the hepatic activity of cytochrome P450, NADPH-cytochrome C reductase, AHH, NDMA-dI, GST and GSH by 112, 122, 82, 99, 64 and 26%, respectively. These herbs decreased the activity of above mentioned enzymes in the liver of diabetic rats compared to alloxan-treated rats. We conclude that alloxan increased the activity of cytochrome P450 system and that such herbs reduced these activities. The toxic effects of PAHs (e.g. benzo(a)pyrene) and NNA (e.g. N-nitrosdimethylamine) could be increased in the liver of diabetic rats through induction of their corresponding bioactivating enzymes. On the other hand, hypoglycemic herbs could alleviate the deleterious effects of these carcinogens in the liver of diabetic rats since these herbs reduced the hepatic content of cytochrome P450 and other associated enzyme activities compared to the diabetic group. Such alterations in the activity of phase I and II drug-metabolizing enzymes should be considered when therapeutic drugs are administered to diabetic patients since most of drugs are metabolized mainly by the cytochrome P450 system.

Synthesis and structure-activity relationships of novel naphthalenic and bioisosteric related amidic derivatives as melatonin receptor ligands.

A series of N-naphthylethyl amide derivatives were synthesized and evaluated as melatonin receptor ligands. The affinity of each compound for the melatonin receptor was determined by binding studies using [2-125I]iodomelatonin on ovine pars tuberalis membrane homogenates. Structure-activity relationships led to the conclusion that naphthalene is a bioisostere of the indole moiety of melatonin. Moreover it appears that the affinity is strongly affected by the size of the substituent of the nitrogen of the amidic function. Many of these ligands give biphasic dose-response curves which suggests that there may be two melatonin receptor subtypes within the ovine pars tuberalis cells. The replacement of naphthalene by benzofuran or benzothiophene did not strongly alter the affinity for the melatonin receptor. In contrast, the benzimidazole analogue was a poor ligand. Compound 7, the naphthalenic analogue of melatonin, a selective ligand of the melatonin receptor and an agonist derivative, has been selected for clinical development.

Identification of several human urinary metabolites of 6-benzoyl benzoxazolinone by gas chromatography/mass spectrometry.

The biotransformation of 6-benzoyl benzoxazolinone (6-BB), a non-narcotic peripheral analgesic, was studied in eight healthy volunteers after oral administration of a single dose of 1 g. Urinary metabolites were extracted either with ethyl acetate at different pH values or by percolating at pH 5 through Amberlite XAD 2 ion-exchange resin. Eluates were concentrated under vacuum, purified by thin-layer chromatography and analysed by gas chromatography/mass spectrometry or direct insertion probe mass spectrometry. Metabolites were identified with reference to the mass spectra of various synthesized compounds assumed to be metabolites of 6-BB, as N-methylated or monohydroxylated compounds. Another metabolic pathway was cleavage of the benzoxazolinone heterocycle giving 2-amino-5-benzoyl phenol after hydrolysis and decarboxylation. N-methyl, N-acetyl and hydroxylated metabolites having an amino-5-benzoyl phenol structure were also found.