Efficacy and safety of intranasal buserelin acetate in the treatment of endometriosis: a review of six clinical trials and comparison with danazol.

The efficacy and safety of buserelin acetate in the treatment of endometriosis was studied in 4 open non-comparative trials and 2 open randomized comparative trials with danazol. 444 women were enrolled in the buserelin group and 89 in the danazol group. Treatment was for 6-10 months using 900-1200/micrograms intranasal buserelin/day and 400-800/micrograms oral danazol/day; patients were followed up for 6-8 months. Endometriotic lesions improved or disappeared in most women; pain (dysmenorrhoea, dyspareunia and pelvic pain) subsided rapidly. Most women had no, or alleviated, symptoms throughout follow-up, although ovarian function resumed promptly. Nearly a quarter of infertile women with a desire for children became pregnant. No significant differences between treatments emerged. Buserelin treatment was characterized by menopausal-like symptoms in most women, as well as by headache and nausea. Danazol treatment, which also gave rise to these effects, was accompanied by weight gain, myalgia and acne in a considerable proportion of women, as well as other anabolic and androgenic side effects. Buserelin would thus appear to be a safe and effective alternative to the standard therapy, danazol, in the treatment of endometriosis.

Lymph esterases of the house mouse (Mus musculus)--I. Identification and possible origins of abdominal lymph esterases.

1. Abdominal lymph was obtained from Mus musculus by cannulation of the thoracic duct: lymph esterases were identified by polyacrylamide gel electrophoresis. Seven known esterases (ES-1, ES-2, ES-5, ES-27, SE-I, SE-II and SE-III) and a newly described activity (SE-IV) were demonstrated, all of which were also present in serum. 2. Electrophoretic staining intensities indicated that the lymph esterases were less concentrated than the corresponding activities in serum, with the single exception of ES-2. This finding was supported by quantitative immunoelectrophoresis of ES-1 and ES-2 (two allozymes each). 3. The jejunum appeared to be the origin of lymph ES-2 by a comparison of organ distribution of the allozymes ES-2B and ES-2D and by monitoring the re-appearance of ES-2 in several organs, serum and lymph after total inhibition in vivo by bis-p-nitrophenyl phosphate.

Lymph esterases of the house mouse (Mus musculus)--II. The role of esterase-2 in fat resorption.

1. Intralipid infusion into the duodenum of Mus musculus was accompanied by changes in lymph and serum concentrations of two esterase isozymes, ES-1 and ES-2. Whereas ES-1 levels declined in both lymph and serum, ES-2 levels increased 5-fold in lymph within 120 min, and fell to a plateau 3- to 4-fold the fasting level; serum levels of ES-2 increased continually. 2. The changes in lymph ES-2 concentrations were paralleled by lymph triglyceride concentration during Intralipid infusion. Genetically determined differences in the concentration of two allozymes, ES-2B and ES-2D, were reflected in differences in lymph triglyceride levels. The lymph triglyceride concentration was strongly correlated with approximately the cube root of the lymph ES-2 concentration for both allozymes. 3. The source of lymph ES-2 during fat resorption was probably an intracellular jejunal pool; serum ES-2 also re-entered the lymph but this fraction was not influenced by fat resorption. 4. Purified chylomicrons possessed no esterase activity; however, it was postulated that ES-2 plays an essential role in fat resorption and is extruded with the primary chylomicrons from the enterocyte.

Clinical characteristics of roxatidine acetate: a review.

Pharmacodynamic studies revealed that 150 mg of roxatidine acetate were optimal in suppressing gastric acid secretion, and that a single bedtime dose of 150 mg was more effective than a dose of 75 mg twice daily in terms of inhibiting nocturnal acid secretion. When administered orally as a capsule containing a granule formulation, the drug displayed modified-release properties, which led to a sustained suppression of gastric acid secretion. Clinical trials revealed that roxatidine acetate, 75 mg twice daily and 150 mg at night, was highly effective in healing duodenal and gastric ulcers and in reducing ulcer pain, over 4, 6, and 8 weeks of therapy. A steady reduction in diameter was observed in those ulcers not completely healed during therapy. The single bedtime dose regimen, while producing the same degree of healing as the divided daily dose during controlled clinical trials, may be of greater value in therapeutic use owing to improved patient compliance. In all efficacy criteria (cure, reduction in ulcer size, and pain relief) there was no significant difference between roxatidine acetate in a total daily dose of 150 mg, ranitidine in a total daily dose of 300 mg, and cimetidine in a total daily dose of 800 mg. Prevention of gastric and duodenal ulcer relapse was achieved by roxatidine acetate, 75 mg at night for 6 months, in about 70% of patients, as determined in open, pilot studies--a rate comparable to those reported for cimetidine and ranitidine. Roxatidine acetate shares with ranitidine an improved safety profile when compared with cimetidine. Human pharmacology studies and short-term and long-term clinical trials have all shown that roxatidine acetate is an exceptionally well tolerated compound, without the antiandrogenic activity and interference with hepatic drug metabolism which have characterized cimetidine treatment. A reason for the improved safety profile of roxatidine acetate may be its greater potency than cimetidine (six times less potent) and ranitidine (half as potent), so that lower doses of roxatidine acetate, representing a lower chemical load, are therapeutically effective. The novel structure of roxatidine acetate probably also underlies the improved safety of the compound.

The effects of 75 mg HOE 760, a novel H2-receptor antagonist, on daytime peptone-stimulated and nocturnal gastric acid output in healthy volunteers.

The effects of HOE 760, a highly specific H2-receptor antagonist, on daytime peptone-stimulated and nocturnal gastric acid output were studied (randomized, double-blind crossover) in 10 healthy men. Acid output was monitored at lunch (1200 h to 1400 h) and dinnertime (1800 h to 2000 h) by continuous automatic intragastric titration; from midnight to 0600 h, output was measured by titration of manually aspirated gastric contents. After a 75-mg oral dose (capsule containing HOE 760 granules) at 0800 h peptone-stimulated acid output decreased for at least 12 h. Compared with placebo, significant reductions (p less than 0.05) of 86% and 32% were observed 4-6 h and 10-12 h after drug administration. After another dose of 75 mg at 2100 h nocturnal acid output was significantly reduced (p less than 0.05) by 88%; gastric pH was increased by about 2 units throughout the night. HOE 760 was well tolerated. No adverse reactions occurred; no clinically relevant changes were noted in haematologic, biochemical, urinary, or electrocardiographic variables.

Dose linearity and other pharmacokinetics of cefodizime after single-dose intravenous administration.

Pharmacokinetics of cefodizime, a broad-spectrum cephalosporin antibiotic, were determined after intravenous (IV) administration of single doses of 1.0, 1.5, and 2.0 gm to 12 healthy male volunteers in an open study. In a separate pilot study, data were obtained after IV administration of 0.5 gm of cefodizime to six healthy male volunteers. Determinations of cefodizime in serum and urine using a microbiological assay agreed with determinations using high-pressure liquid chromatography (HPLC), which specifically measures the unchanged drug. Active metabolites of cefodizime were not detected. After IV administration of 1.0, 1.5, and 2.0 gm of cefodizime, initial mean serum concentrations were 215, 322, and 394 mg/L, respectively (HPLC determinations). A linear response to dosage was shown (coefficient of correlation r = .89), as was the case for area under the serum concentration-time curve to infinity, AUC infinity (r = .82), and 48-hour urinary recovery of cefodizime (r = .94). In all cases, the corresponding values obtained after the 0.5-gm dose showed that the linearity extended to this dose. The kinetics of single-dose administration of cefodizime corresponded to a two-compartment open model with an apparent steady-state volume of distribution of about 40 L. Volume of distribution, terminal elimination half-life, serum and renal clearance, and percent urinary recovery were not dose dependent. Cefodizime combined a long terminal elimination half-life (mean, 2.5 hours) with a high urinary recovery (80%). After IV administration of cefodizime, urinary concentrations of the unchanged drug remained above 5 micrograms/ml for at least 24 hours after drug administration and were dose dependent. Mean values for the 1.0-gm and 2.0-gm doses were, respectively, approximately 12 mg/L and 30 mg/L, several times the minimal inhibitory concentrations (MIC90) for most clinically relevant bacteria. These results suggest that once- or twice-daily IV dosing with cefodizime (depending on the dose regimen) would be suitable for clinical use. The drug was safe and well tolerated.

Lack of effect of piretanide (a potassium-stable diuretic) on serum magnesium.

Serum magnesium and potassium concentrations were determined in 188 patients undergoing diuretic treatment for mild to moderate hypertension in four controlled clinical trials (eleven treatment groups). Measurements were made before and after 12 weeks of treatment with piretanide monosubstance (including the retarded form) in the range 3 to 12 mg daily, with triamterene as monosubstance and in fixed dose combination with piretanide, and with amiloride in combination with hydrochlorothiazide. Eumagnesaemia and eupotassaemia were preserved at all dosage of the piretanide monosubstance. Mean serum potassium concentrations were significantly increased following treatment with the potassium-sparing agents triamterene (with and without piretanide) and amiloride in combination with hydrochlorothiazide. These changes were not accompanied by changes in mean serum magnesium levels, that is, a magnesium-sparing effect was not demonstrated. Individual values of changes in serum magnesium levels before and after diuretic therapy did not correlate with the corresponding changes in serum potassium levels in any of the eleven groups of patients. This result is in contrast to the findings of other authors, which suggested that serum magnesium and potassium levels were correlated. Long-term treatment with diuretics can lead to hypomagnesaemia and hypokalaemia, and, if in combination with a potassium-sparer, to hyperkalaemia. The results of this analysis show that piretanide, in addition to its smooth and effective antihypertensive action, is also able to preserve serum magnesium and potassium homeostasis when administered in the range of 3 to 12 mg for 12 weeks.

Multiple-dose pharmacokinetics of ofloxacin, a new broad-spectrum antimicrobial agent.

Twelve healthy male volunteers received 14 oral doses of ofloxacin (300 mg each), and the concentrations of the unchanged drug were measured at various times in serum and urine over a period of 15 days. Serum and urine ofloxacin concentrations were determined in specific assays using high-pressure liquid chromatography (HPLC); urine levels were also determined by means of a microbiological assay. A washout period of 72 hours followed the first and 14th doses, allowing comparison of serum pharmacokinetics at the beginning and end of the multiple-dose regimen. Doses 2 to 14 were administered at 12-hour intervals. Maximum serum concentration (Cmax), concentration at 12 hours after dosing (C12), and area under the serum concentration-time curve (0 to 72 hours) were all 1.3 to 1.7 times greater after the 14th dose than after the initial dose. A 1.6-fold increase in C12 was already evident after the third dose; C12 remained more or less constant thereafter. Thus it is concluded that ofloxacin rapidly attained steady-state serum levels under a multiple-dose regimen, at levels only slightly above those following a single dose. High serum Cmax levels (4.6 and 5.9 micrograms/ml after the first and 14th doses, respectively) and long serum half-lives (6.0 and 7.3 hours after the first and last doses, respectively) indicated long-lasting, clinically relevant serum ofloxacin concentrations after oral administration. Serum ofloxacin levels 24 hours after the last dose were in the range of 0.3 to 0.7 microgram/ml, above the minimal inhibitory concentration (MIC90) for most bacterial strains. Cumulative urinary recovery remained high throughout the study. After 14 doses of ofloxacin (total, 4.2 gm), 88% of the unchanged drug was recovered in the urine; urinary concentrations remained above 1 microgram/ml, far above the MIC90 for most bacterial strains, for at least 108 hours after the final dose. High renal clearance values relative to total clearance (98%) confirmed the importance of the renal elimination route. Determinations of ofloxacin in urine using a microbiological assay were in close agreement with the HPLC determinations for all samples obtained throughout the study. Thus no detectable appearance of active metabolites occurred under the multiple-dose regimen. Ofloxacin was well tolerated; mild, probably drug-induced side effects were reported by three subjects, but they did not require any countermeasures.

Biochemistry and genetics of esterase-20 (ES-20), a second trimeric carboxylesterase of the house mouse (Mus musculus). I. Purification and characterization of ES-20C1 from male kidney.

ES-20 was isolated from male mouse kidney and purified 350-fold by ion-exchange chromatography, isoelectric focusing, and gel filtration. The resultant product was apparently homogeneous by the criteria of polyacrylamide gel electrophoresis and immunodiffusion and represented a major fraction of male mouse kidney esterase. Sodium dodecyl sulfate gel electrophoresis revealed the presence of a single subunit band, molecular weight 59,500; the molecular weight of the native protein was found to be 179,000. Titration of the active site yielded an equivalent weight of about 175,000. The enzyme was further characterized by its kinetic parameters for the hydrolysis of a series of 4-nitrophenyl esters and was classified as a carboxylesterase (EC 3.1.1.1). ES-20C1 bound to concanavalin A, indicating that it was a high-mannose-type glycoprotein; the role of terminal beta-N-acetylglucosamine residues in the carbohydrate side chains for stabilization of the quaternary structure of the trimer was revealed. Extensive biochemical and immunological similarities to ES-9C supported an earlier suggestion that the Es-9c gene product is a component of the ES-20C1 trimer.

Biochemistry and genetics of esterase-20 (ES-20), a second trimeric carboxylesterase of the house mouse (Mus musculus). II. A unique recombination reveals ES-20 as a hybrid enzyme.

A unique recombination is described between (Es-1, Es-6) and (Es-9, Es-22) within gene cluster 1 of the esterase gene region on chromosome 8 of the house mouse. This recombination established the gene order Es-1--Es-6--(Es-9, Es-22)--Got-2. A further 73 recombinations, from a total of 911 backcrosses, had taken place between cluster 1 and cluster 2. A distance between the clusters of 8.01 +/- 0.90% was calculated; the genes within the clusters appeared more tightly linked than previously assumed. ES-20 behaved anomalously following the recombination within cluster 1: homozygous descendants of the recombinant expressed a new form of ES-20. In vitro incubation of purified ES-6A3 and ES-9A generated ES-20A, revealing this esterase to be a hybrid of different cluster 1 gene products, Es-9 and possibly Es-6. This result satisfactorily accounted for the genetic finding, as well as a range of biochemical properties of ES-20.

Nonspecific esterases of mammalian testis. Comparative studies on the mouse (Mus musculus) and rat (rattus norvegicus).

Ten different nonspecific esterases in both mouse (Mus musculus) and rat (Rattus norvegicus) testis were identified following the analysis of electrophoretic patterns using genetic, developmental, and biochemical criteria. None of the enzymes were unique to testis, although the pattern of activity was testis specific. The enzymes comprised, in each species, six carboxylesterases (EC 3.1.1.1), one arylesterase (EC 3.1.1.2), one acetylesterase (EC 3.1.1.6), and two butyrylesterases (tentative designation). Cholinesterase (EC 3.1.1.8) was not detected. Individual homology relationships were recognized between the two species for all of these activities, except three of the carboxylesterases; however, these were coded for by homologous gene clusters. Similarities between the two species extended to the developmental course of expression and the modulation of the pattern of activity by the testicular feminization (Tfm) mutation. We describe the effects of the sex reversal (Sxr) mutation in the mouse, as well as the distribution of individual activities between Leydig cells and seminiferous tubules. The results of earlier histochemical studies are interpreted in the light of the present investigation. The correspondence between mouse- and rat-testis esterases suggests that the results could serve as a basis for mammalian testis esterase systems in general.

Identification and development of a genetically closely-linked carboxylesterase family of the mouse liver.

Six carboxylesterase isozymes (viz. ES-1, ES-6, ES-9, ES-20, ES-22 and ES-24), governed by esterase gene cluster 1 on chromosome 8 of the house mouse, were identified electrophoretically in liver supernatants using their biochemical, genetic and developmental characteristics. ES-1 and ES-20 were expressed as liver-specific forms. The peri- and postnatal development of the six isozymes indicated that they were individually regulated at the genetic level, although the isozymes were regulated as a group when compared to genetically unrelated esterases. The concept of evolutionary divergence following repeated gene duplication of an ancestral esterase structural gene was extended to cover divergence of the temporal (regulatory) genes associated with the multigene family. Allelic variation of the temporal genes was more limited than that of the corresponding structural genes.

Human red cell butyrylesterase, and its homologies in thirteen other mammalian species.

The selective staining of a single butyrylesterase, following isoelectric focusing of red cell lysates from 14 mammalian species, including man, was achieved using the chromogenic substrate N-acetyl-L-alanine-alpha-naphthyl ester. This procedure optimized the identification of this enzyme, and a close correspondence of its properties was observed in all the species investigated. The inhibition profile, using a range of inhibitors, was identical in all cases. Particularly noteworthy was the activation of the enzyme by p-chloromercuribenzoate at low (2-20 x 10(-6) M) concentrations, but inhibition at higher (greater than 10(-3) M) concentrations. The isoelectric points of all samples fell within a narrow range, pI 4.00-4.43. Descriptions of this activity in different animals, under different designations, could be identified in earlier studies, and the enzyme was uniformly designated "butyrylesterase 1". A tetrameric subunit structure, previously established for the human enzyme, was also demonstrated in the case of mouse butyrylesterase 1. A list of diagnostic characteristics for the enzyme was presented, and it was assumed that the 14 enzymes investigated are orthologous. It was not possible to group butyrylesterase 1 with any other known esterase within the system of enzymes recommended by the IUB, and it was proposed that this enzyme be assigned to a new esterase subclass.

Purification and characterization of esterase 6A, a trimeric esterase of the house mouse (Mus musculus).

Esterase 6A was isolated from mouse lung and purified 440-fold by ion-exchange chromatography, inverse ammonium sulphate gradient solubilization, gel filtration and isoelectric focusing. The resultant product was apparently homogenous by the criteria of polyacrylamide gel electrophoresis and immunodiffusion, and consisted of the electrophoretic form 6A3. A single species of subunit was present on sodium dodecyl sulphate gel electrophoresis. The molecular weight of the native protein was found to be about 178,000 with a subunit molecular weight of about 60,000. The equivalent weight obtained by active-site titration with diethyl-p-nitrophenyl phosphate was approximately 178,000 g/mol, indicating a functional asymmetry in the trimer. The enzyme was shown to have a high affinity for 4-nitrophenyl hexanoate (Michaelis constant Km = 4.4 mumol/l) with a relatively low catalytic efficiency (catalytic constant kcat = 12 s-1). Esterase 6A was immunologically related to esterase 1 and esterase 9, with which it is genetically closely linked. Further properties of the three esterases were compared.

Organ specific expression of esterase-6 in the house mouse, Mus musculus.

Esterase-6 in fresh homogenates of heart muscle and testis of the house mouse shows a two band (C allele) or three band (A allele) pattern in disc electrophoresis. These primary bands generated in series of secondary bands upon lowering the pH of the homogenates, and the secondary pattern, possibly resulting from partial proteolysis, was seen in varying degrees in fresh homogenates from a range of organs. Interrelationships between the primary and secondary bands were demonstrated by isoelectric focusing. The esterase-6 content of twenty different organ homogenates was estimated from electrophoretic gels, and a high level of this enzyme was observed in those organs most actively involved in fat metabolism. The possible participation of esterase-6 in fatty acid utilization is discussed. Similarities between esterase-6 of the house mouse and esterase-4 of the rat were demonstrated, further strengthening the view that these enzymes are homologous.