[Retroequatorial myopexy combined with bimedial recession for near-distance disparity esotropia]

PURPOSE

In cases of esotropia combined with a high AC/A ratio, partly accommodative convergence excess or with nonaccommodative convergence excess, two methods of surgical therapy are possible: recession of the medial recti (Parks) and retroequatorial myopexy (Cüppers). Our aim was to answer the question whether retroequatorial myopexy alone and in combination with bimedial recession are appropriate methods of reducing the strabismic angle at near and distant fixation to values under 10 PD and near-distance disparity to less than 10 PD to form the basis for single binocular vision without bifocals.

PATIENTS AND METHODS

Eighty-three patients, aged 2-14 years (39 boys and 44 girls), were included in the study: 37 children (group A) with early-onset near-distance esotropia of 14-48 PD for distance and 26-65 PD for near objects and 46 children (group B) with acquired near-distance esotropia of 8-45 PD for distance and 26-70 PD for near objects. Inclusion criteria were a near-distanced disparity of at least 10 PD (range 10-33 PD), a follow-up of at least 3 months (median 5 months, range 3-69 months), retinoscopy in cycloplegia and full refractive correction. The amount of conventional surgery was chiefly based on the distance angle of esotropia. The myopexy was placed 12, 13 and 14 mm behind the insertion of the medial rectus.

RESULTS

In 73 of 83 patients (88%) we were able to reduce the strabismic angle for distance and near fixation to less than 10 PD and in 73 cases even under 5 PD. In 77 of 83 patients (93%) the near-distance disparity was reduced to less than 10 PD and in 72 patients (87%) even under 5 PD. Postoperatively, 9 children had bifocals, but 3 of them have meanwhile discarded them. Two cases were slightly ocvercorrected and 1 case undercorrected. Seventy children (84%) attained grade of binocularity.

CONCLUSION

Retroequatorial myopexy (fadenoperation) alone and combined with bimedial recession is an effective procedure in treating esotropia with abnormal near-distance disparity.

Stereopsis after primary in-the-bag posterior chamber implantation in children

PURPOSE

The purpose of this study was to evaluate visual acuity and binocular function after primary posterior chamber intraocular lens (IOL) implantation in children.

PATIENTS AND METHODS

A retrospective chart review of 39 eyes of 31 children was performed. Fifteen eyes with traumatic, 17 with developmental, and 7 with congenital cataracts without any other ophthalmologic problems were examined before and after cataract surgery (irrigation/aspiration procedure with implantation of a posterior chamber IOL). Twelve eyes also received a posterior capsulorrhexis and anterior vitrectomy. The mean age at surgery was 6.9 +/- 3 years (range, 3-12 years).

RESULTS

Twenty (51%) of 39 eyes achieved a best-corrected postoperative visual acuity of 20/40 or better (range, 20/200-20/20). The mean postoperative visual acuity was 20/40 in the traumatic and developmental cataract groups and 20/100 in the congenital cataract group. There was a positive correlation between cataract morphology and visual acuity (P<.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (P <.005). Nineteen (70%) of 27 eyes in which no primary posterior capsulorrhexis had been performed had posterior capsule opacification. Stereopsis was found in 10 of the 31 patients: 43% of the traumatic cataract group, 30% of the developmental cataract group, and 14% of the congenital cataract group.

CONCLUSIONS

After capsular bag-fixated IOL, visual acuity and binocular function in children older than 3 years were favorable and the complication rate, excluding posterior capsule opacification, was low.

Long-term cardiovascular safety of salmeterol powder pharmacotherapy in adolescent and adult patients with chronic persistent asthma: a randomized clinical trial

STUDY OBJECTIVES

This study investigates the long-term cardiovascular safety of salmeterol powder vs placebo in adolescent and adult patients with mild persistent asthma.

DESIGN

Multicenter, randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Eighteen US clinical centers.

PATIENTS

Three hundred fifty-two patients (> or = 12 years) with mild persistent asthma (duration > or = 6 months) requiring pharmacotherapy; with FEV1 of 70 to 90% of predicted and without abnormal ECG/continuous ambulatory ECG (Holter).

INTERVENTIONS

Randomized to twice-daily salmeterol powder (50 microg) or placebo via breath-actuated device for 52 weeks. Backup albuterol was available to control asthma symptoms.

MEASUREMENTS AND RESULTS

Cardiovascular safety was regularly assessed by 12-lead ECG with a 15-s lead II rhythm strip, 24-h continuous ambulatory ECG (Holter) monitoring, serial vital sign measurements, and review of adverse cardiovascular events. No deaths occurred during the study. No clinically significant between-group differences were observed in pulse rate, ECG QTc interval, median number of ventricular or supraventricular ectopic events, incidence of ventricular ectopic couplets and runs, or incidence of > 100 ventricular or supraventricular ectopic events in 24 h. No clinically significant between-group differences were observed in arterial BP or incidence of adverse cardiovascular events. Salmeterol was well tolerated throughout the 52-week study period, with a cardiovascular safety profile similar to that of placebo.

CONCLUSIONS

Long-term, twice-daily pharmacotherapy with salmeterol powder is safe and is not associated with unfavorable clinically significant changes in cardiac function or increases in cardiovascular adverse effects.

Prevention of exercise-induced bronchospasm in pediatric asthma patients: a comparison of salmeterol powder with albuterol

BACKGROUND

Exercise-induced bronchospasm (EIB) is a common problem in children with asthma. Pretreatment with the beta2 (beta 2)-adrenoreceptor agonist albuterol is effective for preventing EIB, but is recognized as providing only short-term (2 to 3 hour) protection.

OBJECTIVE

To evaluate the 12-hour efficacy and safety of single doses of 25 micrograms and 50 micrograms of salmeterol powder administered via Diskus inhaler versus albuterol aerosol via pressurized metered-dose inhaler and placebo in preventing EIB in asthmatic children.

METHODS

A randomized, double-blind, placebo-controlled, double-dummy, single-dose, four-way crossover study was conducted in pediatric patients (4 to 11 years of age) demonstrating EIB and mild-to-moderate asthma. Serial forced expiratory volume in 1 second (FEV1) was measured before and after standard treadmill exercise at hour 1, hour 6, and hour 12 after administration of 25 micrograms or 50 micrograms salmeterol powder, 180 micrograms albuterol aerosol, or placebo. Adverse events were recorded.

RESULTS

After completion of the hour 1 exercise challenge, mean minimum % predicted FEV1 was significantly higher following albuterol (91.3%) than for placebo (75.3%) and for both dosages of salmeterol (86.9% and 85.8% for salmeterol 25 micrograms and 50 micrograms, respectively; P < or = .026). After completion of both the hour 6 and hour 12 exercise challenges, the 50-microgram salmeterol treatment produced a significantly higher mean minimum percent of predicted FEV1 (90.6% and 87.3% predicted, respectively) than the mean minimum percent of predicted FEV1 for placebo or albuterol (73.8% to 78.4% of predicted; P < or = .041). At hour 6, the 25-microgram salmeterol treatment was not significantly different from albuterol or placebo. At hour 12, the 25-microgram salmeterol treatment mean minimum percent of predicted was significantly higher than albuterol (87.9% versus 73.8% of predicted; P = .006) and there was also a trend toward significance over placebo (76.9% predicted; P = .056). At all exercise periods, no statistically significant differences in spirometry values were observed between the two salmeterol treatment groups. Safety profiles were similar among treatments, including placebo. No drug-related adverse events or withdrawals due to adverse events occurred. Changes in laboratory values, vital signs, 12-lead ECGs, and physical examinations were unremarkable.

CONCLUSIONS

A single 50-microgram dose of salmeterol powder provided effective and safe protection against EIB for at least 12 hours in asthmatic children and provided a significantly more prolonged effect than albuterol aerosol (180 micrograms).

Efficacy of salmeterol xinafoate powder in children with chronic persistent asthma

BACKGROUND

The efficacy and safety of salmeterol powder have not previously been evaluated in children with asthma in the United States.

OBJECTIVE

The efficacy and safety of salmeterol powder versus placebo were compared in children between the ages of 4 and 11 years with chronic persistent asthma.

METHODS

A randomized, double-blind, placebo-controlled, parallel group trial was performed at 11 clinical centers. Two hundred seven patients were randomly assigned to receive 50 microg salmeterol powder or placebo (and albuterol as needed) twice daily via a breath-actuated device for 12 weeks. Twelve-hour serial pulmonary function assessments were conducted on day 1 and at week 12. Daily recordings of morning and evening peak expiratory flow (PEF), supplemental albuterol use, asthma symptoms, and nocturnal awakenings were assessed.

RESULTS

On day 1 and at week 12, weighted mean percent of predicted PEF (P < .001, day 1 and P=.008, week 12) and weighted mean forced expiratory volume in one second (P < .001, day 1 and week 12) were significantly higher at all timepoints evaluated over the 12-hour postdosing period in patients treated with salmeterol powder compared with placebo. Overall reductions in supplemental albuterol use and mean asthma symptom scores were also significantly greater in children administered salmeterol compared with placebo (P=.004 and P=.006, respectively). The frequency of adverse events was similar in the two treatment groups.

CONCLUSION

Salmeterol powder (50 microg twice daily) is effective and safe in producing bronchodilation and relieving symptoms in children with chronic persistent asthma during 12 weeks of treatment.

Salmeterol powder compared with albuterol aerosol as maintenance therapy for asthma in adolescent and adult patients

Two multicenter, randomized, double-masked, placebo-controlled studies involving 451 adolescent and adult patients with mild-to-moderate asthma compared the efficacy and safety of salmeterol powder 50 micrograms twice daily with albuterol 180 micrograms four times daily or placebo (with albuterol as needed) for 12 weeks. Patients had forced expiratory volume in 1 second (FEV1) of 50% to 80%. Throughout the 12-week treatment period, the mean change from baseline in percentage of predicted FEV1 was significantly greater with salmeterol than with placebo; mean area under the curve for FEV1 was significantly greater with salmeterol than with albuterol or placebo. Significant improvements in morning and evening peak expiratory flow, percentage of nights without awakening, and asthma symptoms were observed with salmeterol. Salmeterol was well tolerated, and no clinically significant changes in electrocardiographic activity were observed.

Genetic variation within and among populations of Arabidopsis thaliana

We investigated levels of nucleotide polymorphism within and among populations of the highly self-fertilizing Brassicaceous species, Arabidopsis thaliana. Four-cutter RFLP data were collected at one mitochondrial and three nuclear loci from 115 isolines representing 11 worldwide population collections, as well as from seven commonly used ecotypes. The collections include multiple populations from North America and Eurasia, as well as two pairs of collections from locally proximate sites, and thus allow a hierarchical geographic analysis of polymorphism. We found no variation at the mitochondrial locus Nad5 and very low levels of intrapopulation nucleotide diversity at Adh, Dhs1, and Gpa1. Interpopulation nucleotide diversity was also consistently low among the loci, averaging 0.0014. gst, a measure of population differentiation, was estimated to be 0.643. Interestingly, we found no association between geographical distance between populations and genetic distance. Most haplotypes have a worldwide distribution, suggesting a recent expansion of the species or long-distance gene flow. The low level of polymorphism found in this study is consistent with theoretical models of neutral mutations and background selection in highly self-fertilizing species.

[Capsular sack-fixed IOL implantation in pediatric cataract. Visual prognosis and complications]

BACKGROUND

The aim of the study was to evaluate results of visual acuity and binocularity and complications after cataract surgery with primary capsular bag-fixated IOL implantation in children.

MATERIALS AND METHODS

Thirty-three children [mean age (+/- SEM) 6.9 +/- 2.9 years, range 3-12 years] accounting for 43 eyes, were examined before and after surgery (15 traumatic, 19 developmental, and 9 congenital cataracts, of the latter two groups 9 unilateral and 19 bilateral cataracts).

RESULTS

All eyes had a best corrected postoperative visual acuity of 0.5 +/- 0.05. The postoperative visual acuity of the traumatic cataracts was 0.6 +/- 0.07, of the developmental cataracts 0.5 +/- 0.07, and of the congenital cataracts 0.2 +/- 0.05. Of the 43 eyes, 17 (40%) showed a best corrected visual acuity of 0.5 or better. There was a positive correlation between morphology (lamellar versus subcapsular opacification) and visual acuity (0.7 +/- 0.07 versus 0.5 +/- 0.05; P < 0.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (0.7 +/- 0.07 versus 0.2 +/- 0.05 P< 0.001) Stereopis was found postoperatively in 62% of the children. In one eye a capsular bag-fixated IOL implantation was not possible, and so the IOL was inserted in the sulcus. Four children presented with postoperative fibrin formation. Posterior capsule opacification occurred in 19% of the eyes in which a primary posterior capsulotomy had been performed.

CONCLUSIONS

The prognosis of visual acuity and the results of stereopsis in children older than 3 years following capsular bag-fixated IOL implantation are very good. Both the intraoperative and postoperative complication rates were low.

[Regulation of glutathione level in venous plasma and aqueous humor in cataracta senilis provecta]

Glutathione is a major component of the mechanisms protecting the eye against oxidants. To analyse the functional status and the regulation of the glutathione system in the eyes of patients with advanced cataract, glutathione concentrations were quantified in venous plasma and aqueous humor.

METHODS

In all, 42 patients with advanced cataract (29 women, 13 men; mean age (+/- SEM) 70 +/- 2 years; vision < or = 0.3) were evaluated. Aqueous humour and venous plasma were obtained at the beginning of cataract surgery.

RESULTS

Levels of total glutathione [reduced (GSH) + oxidized glutathione (GSSG)] in plasma were 2.34 +/- 0.23 microM. There was 2.08 +/- 0.15 microM in the reduced form and 0.27 +/- 0.17 microM oxidized glutathione, which means that 94.7 +/- 2.1% of the total glutathione was GSH, the form fully functional as an antioxidant. Levels of total glutathione in the aqueous humor were 1.2 +/- 0.16 microM, i.e. 54.5 +/- 4.8% of plasma levels. Surprisingly, the percentage of GSSG in aqueous humor (0.24 +/- 0.07 microM, 31 +/- 10.5% of the total glutathione) was much higher than that in plasma (P < 0.001). The correlation between glutathione concentrations in plasma and aqueous humor was on the borderline of significance (rs = 0.32, P < 0.04).

CONCLUSION

The proportion of oxidized glutathione is higher in aqueous humor than in plasma of patients with advanced senile cataracts, indicating increased oxidant stress in the eye. Further, the regulation of the glutathione system in the eye, at least in aqueous humor, is dependent on plasma glutathione levels. This correlation reflects the importance of sufficient glutathione levels in venous plasma and suggests the possibility of modulating the glutathione system in the eye via manipulation of plasma glutathione levels.

Disposition and covalent binding of ibuprofen and its acyl glucuronide in the elderly

Ibuprofen is an over-the-counter nonsteroidal anti-inflammatory drug with a low incidence of severe adverse reactions. It is metabolized by oxidation to carboxyibuprofen and hydroxyibuprofen and by conjugation to an acyl glucuronide. In vitro studies have indicated that ibuprofen glucuronide is labile and reactive, forming covalent adducts with proteins. To verify the formation of ibuprofen-protein adducts in vivo, the pharmacokinetics of ibuprofen glucuronide and its covalent binding to plasma proteins were studied in five elderly patients who received long-term administration of oral doses of ibuprofen. Plasma levels of ibuprofen glucuronide were low relative to those of ibuprofen; the ratio of area under the plasma concentration versus time curve for the glucuronide relative to the parent drug was only 4%. Covalent binding of ibuprofen to plasma protein was observed in all patients, correlating well with the area under the plasma concentration versus time curve of ibuprofen glucuronide (r = 0.966). Compared with reports for other nonsteroidal anti-inflammatory drugs that form acyl glucuronides, plasma levels of ibuprofen-protein adduct are low during long-term administration. The observed lower reactivity in vivo is probably attributable to the greater stability of ibuprofen glucuronide relative to other acyl glucuronides.

Assessment of the ability of young children to use a powder inhaler device (Turbuhaler)

The purpose of the study was to determine the age at which young asthmatic children could master the use of a new powder inhaler device (Turbuhaler). We studied 59 children with asthma between the ages of 3 and 6 years who consecutively attended the asthma clinic of the pediatric department. Efficiency of inhalation and the pharmacological effect of the terbutaline in the inhaler were measured by scores for inhalation technique and clinical response. None of the 3-year-old children used the device efficiently, but 43% of the 4-year-old, 67% of the 5-year-old, and 80% of the 6-year-old children used the inhaler correctly. Although inhaler technique was not perfect in the younger age group, 50% of the 3-year-old children demonstrated clinical improvement of asthma symptoms after inhalation. In the older age groups, 79%, 92%, and 100% of the 4, 5, and 6-year-old children demonstrated clinical improvement of asthma symptoms after inhalation. It is concluded that the new mode of dry powder delivery system (Bricanyl Turbuhaler) can be used in young asthmatic children who are 4 years of age and above.

[Lung manifestation of progressive systemic scleroderma. Computerized tomographic findings]

Progressive systemic scleroderma (PSS) is caused by generalized connective tissue disorder. The most frequent visceral manifestations are pulmonary and oesophageal involvement. Early detection of such visceral manifestations, which are sometimes life-limiting, is of paramount importance in any diagnostic procedures. The sensitivity of the methods differs and depends on the stage of the disease. Modified high-resolution computed tomographic scans (HRCT) were obtained in 28 patients with early forms of PSS and showed pulmonary involvement in 79% and signs of oesophageal involvement in 54%. HRCT is much more sensitive than chest radiography, lung scintigraphy and lung function tests even at an early stage of the disease. Classification of PSS should take account of the clinical type of sclerosis and of immunological and other parameters of prognostic importance.

In vivo assessment of pulmonary oxidant damage: the role of bronchoalveolar lavage

Oxidants can cause injury and cell death by modifying and/or disturbing the structure and function of any cellular or non-cellular component. There is overwhelming evidence that a variety of lung disorders are mediated, at least in part, by oxidants causing tissue damage, especially since its location, anatomy, and function makes the lung a primary target for oxidant injury. Bronchoalveolar lavage (BAL) is an excellent tool to evaluate these mechanisms in vivo. BAL allows the repetitive sampling of the cellular and non-cellular components of the fluid lining the epithelium of the lower respiratory tract with minimal risk and discomfort for the patient. The analysis of cell numbers, differential cell counts, cellular functions, and concentrations and functional properties of non-cellular components of BAL fluid continuously improves our understanding of the pathogenesis of lung diseases and of the pathogenetic role of oxidants and antioxidants in particular, by "looking into the living lungs." Further, the ready access of the respiratory epithelial surface by BAL provides opportunities to evaluate and monitor therapeutic strategies directed at reducing the oxidant burden and/or augmenting the antioxidant defense mechanisms in the lower respiratory tract, thereby correcting an oxidant-antioxidant imbalance directly at the site of disease.

Carvedilol stereopharmacokinetics in rats: affinities to blood constituents and tissues

Carvedilol, a lipophilic beta-adrenoceptor antagonist with vasodilating activities, is characterized by a high as well as stereoselective metabolic clearance and distribution volume. Tissue distribution of carvedilol enantiomers and their conjugates were determined under steady-state conditions in rats (p.o., 10 mg/kg, repetitive dosage; n = 5) and after single i.v. administration in control rats and rats with surgical portacaval shunt (pcs) (10 mg/kg; n = 3 each group). In addition, in vitro plasma protein binding was evaluated. The plasma protein binding of carvedilol in rats is > 98% for total plasma (tp) and > 96% for rat serum albumin (rsa) solution (4%), with enantioselectivity ratios of 1.53 (tp) and 1.27 (rsa). Significantly higher unbound fractions were observed in pcs rats, in part due to reduced protein concentrations. In contrast to plasma, where a preponderance of the R-enantiomer with an S/R ratio of 0.6 was found, S-carvedilol was predominant in all tissues (heart, liver, kidneys, lung, spleen, muscle, and adipose tissue), with S/R ratios of 1.3-1.4 in most of these tissues and 2.3 in liver. This preferential tissue partitioning of S-carvedilol was in accordance with its higher unbound fraction in plasma. Carvedilol accumulated predominantly in the highly perfused and/or eliminating organs liver, kidneys, and lung (tissue/plasma ratios; lung: S 76, R 34; liver: S 21, R 5; kidney: S 8, R 3). A similarly enantioselective distribution into the heart of control as well as pcs rats was observed, where the S-enantiomer concentrations exceeded the plasma concentrations 7-fold.(ABSTRACT TRUNCATED AT 250 WORDS)

Saturable enantioselective first-pass effect for carvedilol after high oral racemate doses in rats

Carvedilol shows a highly enantioselective first-pass extraction after therapeutic p.o. doses with preferential extraction of the S-enantiomer. To investigate, whether the enantioselective first-pass metabolism is saturable, male Sprague-Dawley rats were administered increasing single doses of R/S-carvedilol (p.o., 5-30 mg/kg; i.v., 5 and 10 mg/kg), and the individual stereopharmacokinetics were studied. Like in humans the plasma concentrations of R-carvedilol exceeded always those of S-carvedilol. As expected, a dose-dependent reduction in oral clearance was observed, while the total clearance after the i.v. doses was constant. Beyond 20 mg/kg an increased plasma half-life was found for both enantiomers, which is due to a reduced plasma clearance.

Rats with portacaval shunt as a potential experimental pharmacokinetic model for liver cirrhosis: application to carvedilol stereopharmacokinetics

As an experimental model for reduced liver function rats with surgical portacaval shunts (pcs) may be used. Carvedilol, a nonselective beta-adrenoceptor antagonist with vasodilating activity, is extensively metabolised by phase I as well as phase II pathways. In order to study the stereoselective pharmacokinetics of carvedilol in liver disease, pcs and control rats were given rac-carvedilol intravenously and p.o. The carvedilol enantiomers and their conjugates were assayed in plasma, urine, and bile. Carvedilol was highly bound to plasma proteins; binding was reduced by pcs. In all groups, the plasma concentrations of (R)-carvedilol exceeded those of (S)-carvedilol significantly. In comparison to the control group the plasma concentrations of both enantiomers increased after pcs, while the difference between the stereoisomers decreased. The total clearance decreased proportionally to the decrease in liver weight (30%). Both the apparent oral clearance, as well as its stereoselectivity were reduced, by up to 90 and 43%, respectively. The biliary clearance of the parent drug after i.v. dosage increased in rats with pcs due to the reduced hepatic metabolism.

The effect of the cholecystokinin receptor antagonist MK-329 on meal-stimulated pancreaticobiliary output in humans

To determine the physiological role of circulating cholecystokinin (CCK), the effect of the CCK receptor antagonist MK-329 on upper digestive processes was investigated in six normal volunteers after a mixed meal. In a double-blind, two-period, randomized crossover design, the subjects received either 10 mg MK-329 or placebo orally 3 hours 15 minutes before the meal, which contained 51CrCl3 as food marker. A five-lumen tube with the tip in the distal duodenum allowed continuous marker infusion (57Co-B12) and duodenal aspiration as well as recordings of antral and duodenal motility patterns via three pressure sensors. Postprandially, MK-329 caused a significant reduction of 30%-60% (P less than 0.05) in pancreatic trypsin output during the initial three 15-minute periods; thereafter, the output was virtually the same than after placebo. Thus, the integrated enzyme response was only reduced by 15% (NS) during the 3-hour period beginning 15 minutes after the meal. In contrast, gallbladder contraction, determined by total bile acid excretion, was inhibited by 77% (P less than 0.05), indicating a crucial role of CCK in regulating gallbladder motility. Except for the initial 30 minutes postprandially, MK-329 also induced a significant reduction in duodenal pH with mean values ranging from 3.5 +/- 0.2 to 4.1 +/- 0.3 compared with 4.5 +/- 0.3 to 5.0 +/- 0.4 after placebo (P less than 0.05), probably because of lowered secretion of pancreatic bicarbonate. Gastric emptying rate was significantly accelerated by MK-329 during the initial 75 minutes after the meal, but the time for 50% emptying did not differ from placebo [127.5 +/- 7.7 vs. 140.0 +/- 9.0 minutes (NS)]. No changes were observed in the motility pattern of the proximal duodenum after feeding. Whereas MK-329 only caused a slight increase of the basal plasma CCK concentrations, the postprandial levels were markedly enhanced. Peak concentrations were 10.0 +/- 1.3 vs. 4.0 +/- 0.5 pmol/L after placebo (P less than 0.001), and the integrated response exceeded the control value by 175% (P less than 0.01). The results suggest that circulating CCK is not an essential mediator of the postprandial pancreatic enzyme secretion in humans, whereas it plays a critical role in gallbladder emptying.

Improved enantiospecific RP-HPLC assays for propranolol in plasma and urine with pronethalol as internal standard

For the enantiospecific assay of propranolol in biological material, formation of diastereomeric derivatives is one possible approach. The aim of the present study was the development and optimization of three analytical methods based on different chiral reagents: phenylethylisocyanate and the acyl chloride as well as the isocyanate that are derived from the fluorescent S-flunoxaprofen. Pronethalol is used as internal standard in all three procedures and improves the coefficients of variation significantly. After extraction from human plasma or urine, propanolol is reacted with one of these compounds in anhydrous organic solvents with addition of triethylamine. The diastereomeric derivatives are then resolved on an octadecylsilane column using mixtures of water and methanol with or without addition of glacial acetic acid. Good resolutions of the diastereomeric derivatives are found under these conditions. Conjugates are cleaved prior to analysis using beta-glucuronidase-arylsulfatase and assayed as parent propranolol enantiomers. All three procedures were suitable for analysis of propranolol enantiomers in biological samples in the lower nanogram range (1-2 ng/mL). A preliminary clinical study confirmed the known enantiospecificity in the pharmacokinetics of propranolol and showed high concentrations of conjugates with R/S ratios that were similar to those of the parent enantiomers.

Improved enantiospecific RP-HPLC assays for propranolol in plasma and urine with pronethalol as internal standard

For the enantiospecific assay of propranolol in biological material, formation of diastereomeric derivatives is one possible approach. The aim of the present study was the development and optimization of three analytical methods based on different chiral reagents: phenylethylisocyanate and the acyl chloride as well as the isocyanate that are derived from the fluorescent S-flunoxaprofen. Pronethalol is used as internal standard in all three procedures and improves the coefficients of variation significantly. After extraction from human plasma or urine, propranolol is reacted with one of these compounds in anhydrous organic solvents with addition of triethylamine. The diastereomeric derivatives are then resolved on an octadecylsilane column using mixtures of water and methanol with or without addition of glacial acetic acid. Good resolutions of the diastereomeric derivatives are found under these conditions. Conjugates are cleaved prior to analysis using beta-glucuronidase-arylsulfatase and assayed as parent propranolol enantiomers. All three procedures were suitable for analysis of propranolol enantiomers in biological samples in the lower nanogram range (1-2 ng/mL). A preliminary clinical study confirmed the known enantiospecificity in the pharmacokinetics of propranolol and showed high concentrations of conjugates with R/S ratios that were similar to those of the parent enantiomers.

Bricanyl Turbuhaler in the treatment of asthma: a six week multi-centre study carried out in Sweden, the United Kingdom, Denmark, Norway and Finland

Two hundred and fifty eight adult patients with bronchial asthma participated in an open, parallel group study of 8 wks duration. During a 2 wk run-in period the beta 2-agonist terbutaline (0.5 mg q.i.d) was delivered via a pressurized freon aerosol, Bricanyl metered dose inhaler (MDI). During the following 6 wks, one third of the patients continued with MDI and two thirds with the same dose of terbutaline in the form of dry powder, Bricanyl Turbuhaler. There were no statistically significant differences in the increases in peak expiratory flow rate (PEFR) after inhalation between the two treatment groups. The asthma symptom scores decreased in the Turbuhaler group during the study but remained the same in the MDI group. No difference in use of extra trial medication during the day was found. During the night, the difference was statistically significant in favour of Turbuhaler (p less than 0.05). Turbuhaler was well accepted and easy to use. As compared with the MDI used during run-in, 50% of the patients in the Turbuhaler group preferred to use Turbuhaler and 26% MDI, whilst 24% had no preference. In conclusion, Turbuhaler was at least as effective as MDI during the whole Turbuhaler life-span (6 wks).

Barefoot in the OR

In 1988 Dr. Sylvia Uhthoff Munro, an Ottawa general practitioner, and her husband Martin Munro, a professional engineer, spent a year at a small hospital in Ialibu, in the Southern Highlands of Papua New Guinea. The way medicine is practised there may be primitive by Canadian standards, she learned, but the country also proved to be a valuable classroom, one where the lessons came very quickly.

In vitro activity of biosynthetic human diarginylinsulin

In diarginylinsulin two arginine residues are located at the C-terminal end of the B-chain (ArgB31 and ArgB32). This accounts for a shift of the isoelectric point from pH 5.4 in native insulin to pH 7.0 in diarginylinsulin leading to pharmacodynamic characteristics of an intermediate acting insulin when administered s.c. as pH 4.0-5.0 solution. We have investigated insulin receptor binding and biological activity of biosynthetic human diarginylinsulin in human adipocytes and compared to native insulin and proinsulin. Association- and dissociation studies of insulin receptor binding revealed no differences for diarginylinsulin and native insulin. In competition studies under steady-state binding conditions, half-maximal displacement of tracer occurred at 352 +/- 33 pmol/l, 337 +/- 32 pmol/l and 3640 +/- 480 pmol/l for diarginylinsulin, insulin and proinsulin, respectively. The biologic potency of human diarginylinsulin was evaluated by the ability to stimulate D-glucose transport and by the assessment of the antilipolytic activity. Activation of D-glucose transport was half-maximal at 49.6 +/- 5.4 pmol/l (diarginylinsulin), 44.8 +/- 5.8 pmol/l (insulin) and at 476.7 +/- 134.3 pmol/l (proinsulin). Half-maximal inhibition of lipolysis occurred at 13.9 +/- 3.4 pmol/l, 15.4 +/- 2.9 pmol/l and 138.4 +/- 38.6 pmol/l, respectively. In conclusion, diarginylinsulin has almost identical insulin receptor binding characteristics and full biological activity in vitro compared to native insulin. This pharmacodynamically intermediate acting insulin preparation is therefore of potential therapeutical value.