Land-use choices follow profitability at the expense of ecological functions in Indonesian smallholder landscapes.

Smallholder-dominated agricultural mosaic landscapes are highlighted as model production systems that deliver both economic and ecological goods in tropical agricultural landscapes, but trade-offs underlying current land-use dynamics are poorly known. Here, using the most comprehensive quantification of land-use change and associated bundles of ecosystem functions, services and economic benefits to date, we show that Indonesian smallholders predominantly choose farm portfolios with high economic productivity but low ecological value. The more profitable oil palm and rubber monocultures replace forests and agroforests critical for maintaining above- and below-ground ecological functions and the diversity of most taxa. Between the monocultures, the higher economic performance of oil palm over rubber comes with the reliance on fertilizer inputs and with increased nutrient leaching losses. Strategies to achieve an ecological-economic balance and a sustainable management of tropical smallholder landscapes must be prioritized to avoid further environmental degradation.

[Phacoemulsification of human lens nucleus with a water jet]. / Zerkleinerung humaner Linsenkerne mittels Waterjet.

BACKGROUND: Today, phacoemulsification with ultrasound represents the gold standard in cataract surgery. Nevertheless, new technologies for this operation are being developed to reduce the loss of endothelial cells, the heating of the tissue, and the size of the accesses. In addition to bimanual phacoemulsification, laser phacoemulsification, and mechanic phacolysis, the waterjet is discussed as an alternative. MATERIALS AND METHODS: Human soft and hard nuclei of the lens obtained by extracapsular cataract extraction (ECCE) were divided in the water bath with the waterjet, whereby the parameter pressure was varied and the time needed for fragmentation was recorded. RESULTS: In spite of different consistencies, all nuclei could be divided under the direct force of the waterjet. For the emulsification of hard nuclei of the lens, a pressure of no less than 10 bar was necessary. This value was obviously higher than a lens capsule can tolerate. For the fragmentation of soft nuclei of the lens with lower acceptable pressures of 5 bar, comparatively long operating times (in some cases over 5 min) were measured. This means that also in these cases a pressure of 10 bar was required. CONCLUSION: Intraocular use of the waterjet with direct effect of the stream with these pressures is not justifiable. Instruments for waterjet phacoemulsification should be developed which pose no danger to the corneal endothelium and lens capsule.

[Examination of resistance of the lens capsule against the waterjet]. / Untersuchungen zur Belastung der Linsenkapsel durch den Waterjet.

BACKGROUND: Although cataract surgery is highly developed today, there are still problems such as secondary cataract. In polishing the posterior capsule lens, epithelial cells often remain, causing secondary cataracts. Additionally, there are the problems of tissue heating and endothelial cell loss during phacoemulsification by ultrasound. This could be another field for improvement of cataract surgery by using the waterjet. METHODS: After removing the cornea of freshly enucleated porcine bulbs, we used the water jet from 4 to 12 bar. The hit angel on the capsule varied between 45 degrees and 90 degrees. RESULTS: Rupture of the posterior capsule occurred at a mean of 8.5 bar using the jet at 45 degrees and a mean of 8.6 bar using the jet at 90 degrees. CONCLUSION: The waterjet pressure should not be over 4 bar during polishing of the posterior capsule.

[Potential of the water jet in cataract surgery]. / Was kann der Wasserstrahl in der Kataraktchirurgie?

UNLABELLED: Though cataract surgery is highly developed today, there are still problems such as endothelial cell loss after surgery and the occurrence of aftercataract. To reduce these complications we looked for techniques with a high degree of safety and precision. We found the water jet, an instrument already well established in liver surgery. We tested the possibility of improving the results of cataract surgery using the water jet method. METHODS: We performed cataract surgery--phacoemulsifikation and polishing of the capsule--on freshly enucleated porcine bulbs using water jet and by conventional procedures. By scanning electron microscope examination we compared the results. Additionally we emulsified human lens nuclei obtained by extracapsular cataract extraction using the water jet. RESULTS: The epithelial cells and lens fragments on the capsule were considerably reduced after the water jet procedure. CONCLUSION: The results show the possibility of improvement of cataract surgery by using the water jet. Further studies are necessary to adapt this technique to routine surgery in humans.

[Possibilities and limits of extracranial vascular diagnosis with conventional echography]. / Möglichkeiten und Grenzen der extrakraniellen Gefässdiagnostik mittels konventioneller Echographie.

BACKGROUND: For the extracranial and partial intracranial diagnosis of vessels Doppler ultrasonography has been the method of choice since a long time. If not the phenomenon of flow, but anatomical structures are of interest, or biopsy is planned, the conventional ultrasonography is often under-estimated. PATIENTS AND METHODS: A detection of the superficial temporal artery and its branches was performed in a clinical study of 50 patients by using a 10 Mhz ultrasonic system. The ultrasonic findings were correlated with clinical findings. RESULTS: The vessel course, the vessel was detectable diameter, plaques and stenosis and the perivascular tissue. CONCLUSIONS: The availability of conventional ultrasonic tools provides the possibility to achieve a fast first documentation of the extracranial vessels in a lot of inflammatory and arteriosclerotic diseases.

Clinical pharmacokinetics of theophylline during co-treatment with cefaclor.

The effect of cefaclor on the steady state pharmacokinetics of theophylline was investigated in healthy young adults by comparing the pharmacokinetic parameters as found during a nine days course of theophylline alone and as obtained during co-medication with the antibiotic cefaclor. The pharmacokinetic parameters obtained on Day 9 during the two periods of drug treatment accounted for the following figures respectively: minimum plasma concentration 5.0 +/- 1.7 mg X 1(-1) (mean +/- SD) and 6.0 +/- 2.0 mg X 1(-1); maximum plasma concentration 9.7 +/- 2.6 mg X 1(-1) and 9.0 +/- 2.6 mg X 1(-1); time to peak 3.2 +/- 0.4 h and 3.9 +/- 0.8 h; AUC 132.54 +/- 41.73 mg X 1(-1) X h and 126.90 +/- 40.45 mg X 1(-1) X h; half-life of elimination 6.6 +/- 1.6 h and 7.1 +/- 1.2 h; clearance 0.059 +/- 0.011 1 X h-1 X kg-1 and 0.063 +/- 0.014 1 X h-1 X kg-1; volume of distribution 0.54 +/- 0.09 1 X kg-1 and 0.64 +/- 0.17 1 X kg-1. Only the values for cmax and tmax after cefaclor co-treatment were slightly, but significantly (p less than 0.05) different from the values found after administration of theophylline alone. As the volume of distribution and the clearance were not affected by cefaclor, it is concluded that both drugs can be given concomitantly without any dosage adjustment of theophylline.

Lack of influence of co-trimoxazole on theophylline pharmacokinetics.

In an open cross-over experiment, the influence of the antimicrobial agent co-trimoxazole on the single-dose pharmacokinetics of theophylline was studied in six healthy adults by comparing the pharmacokinetic parameters found after intravenous administration of theophylline without and with co-medication of co-trimoxazole for the previous 8 d. Theophylline concentrations in plasma were measured by high-performance liquid chromatography (HPLC) analysis. During each treatment, a concentration-time curve was evaluated. No influence of co-trimoxazole on the rate of elimination and volume of distribution of theophylline could be found, as a result of which theophylline concentrations in plasma were not significantly different in both periods of drug administration. A similar lack of influence of co-trimoxazole may apply to the steady-state pharmacokinetics of theophylline. The present study suggests that both drugs can be given concomitantly without the need for dosage adjustment of theophylline.

Lack of effect of amoxicillin on theophylline pharmacokinetics.

The effect of the antibiotic drug amoxicillin on steady state pharmacokinetics of theophylline was studied in healthy adults by comparing the pharmacokinetic parameters as found during a 9 day course of theophylline alone and as obtained during comedication with amoxicillin. Theophylline plasma concentrations were measured by means of h.p.l.c. analysis. On the ninth day of each of the two periods of drug administration a concentration-time curve was evaluated. It showed no influence of amoxicillin on absorption, elimination and volume of distribution of theophylline, as a result of which mean steady state plasma concentrations were not significantly different during both treatments. It is concluded that both drugs can be given concomitantly without any dosage adjustment of theophylline.

Clinical pharmacokinetics of amoxycillin and theophylline during cotreatment with both medicaments.

The influence of amoxycillin and theophylline on their mutual steady-state pharmacokinetics was studied in healthy adults by comparing the pharmacokinetic parameters as obtained during a 10-day course of each drug alone and after giving the drugs in combination. Amoxycillin and theophylline plasma concentrations were measured by means of HPLC methods. On the 9th day of each of the two periods of drug administration, a concentration-time curve was evaluated. These showed no influence of theophylline on absorption, elimination or volume of distribution of amoxycillin, demonstrating that the mean steady-state plasma concentrations were not significantly different during the two treatments. Amoxycillin also has no significant effect on theophylline steady-state pharmacokinetics. It is concluded that both drugs can be given concomitantly without any dosage adjustment.

No influence of doxycycline on theophylline pharmacokinetics.

The influence of the antibiotic drug doxycycline on steady-state pharmacokinetics of theophylline was studied in nine healthy adults by comparing the pharmacokinetic parameters measured during a 9-day course of theophylline alone and during comedication with doxycycline. Theophylline plasma concentrations were measured by means of high performance liquid chromatography analysis. Trough theophylline plasma concentrations were measured on days 1-8. On day 9 of each of the two periods of drug administration, a plasma concentration-time curve was evaluated. No influence of doxycycline on absorption, elimination, and volume of distribution of theophylline was found. Mean steady-state plasma concentrations were not significantly different during the two treatments. It is concluded that the drugs can be given concomitantly without any dosage adjustment of theophylline.

No effect of cefaclor on theophylline pharmacokinetics.

The effect of the antibiotic drug cefaclor on steady state pharmacokinetics of theophylline was studied in healthy adults by comparing the pharmacokinetic parameters as found during a 9 days course of theophylline alone and as obtained during comedication with cefaclor. Theophylline plasma concentrations were measured by means of HPLC analysis. On the ninth day of each of the 2 periods of drug administration, a concentration-time curve was evaluated. It showed no influence of cefaclor on volume of distribution and clearance of theophylline and only a slight, but significant (p less than 0.05) influence on the values for Cmax and tmax after cefaclor co-treatment. It is concluded that both drugs can be given concomitantly without any dosage adjustment of theophylline.

Determination of ibuprofen in human plasma by solid phase extraction and reversed-phase high-performance liquid chromatography.

A new, sensitive and simple method for the rapid quantitative determination of ibuprofen in human plasma has been developed. This method involves the use of a solid phase extraction on "Baker" C-18 disposable extraction columns for sample clean-up and uses mefenamic acid as an internal standard. Separation and quantitation are performed by reversed-phase liquid chromatography using a Nucleosil C18 column and methanol-0.04 M phosphoric acid (80:20, v/v), as the mobile phase. Detection was achieved by UV-absorbance measurements at 229 nm.

The absolute bioavailability of a new pediatric sustained release theophylline tablet, when given as whole or divided tablets.

Absorption characteristics and absolute bioavailability of a new sustained release theophylline tablet for pediatric use were investigated in seven volunteers, both after administration of whole tablets and tablets broken into four equal parts. An intravenous infusion of 200 mg theophylline (as aminophylline) was also administered to the same panel of subjects. Theophylline plasma concentrations were measured frequently during a period of 33 h post dosing. Both after intake of the whole and the broken tablets steadily increasing theophylline plasma concentrations were found. The maximum concentration was found after 5.2 +/- 0.6 h (mean +/- S.D.) and 5.3 +/- 2.2 h and measured 2.00 +/- 0.28 mg.1-1 and 2.46 +/- 0.60 mg.1-1, respectively. The absorption process continued for a considerable period. As a consequence the theophylline plasma concentrations remained above 75% of the maximum value during a period of 8.9 +/- 2.1 h and 8.6 +/- 2.0 h. The absolute bioavailability of the whole tablets was 91.8 +/- 24.7% and that of the broken tablets was 95.8 +/- 9.7%.

Chronopharmacokinetics of theophylline after sustained release and intravenous administration to adults.

The influence of time of drug administration on pharmacokinetics of theophylline was studied both after ingestion of a sustained-release tablet, containing choline theophyllinate ( Zy 15061-S. R.; Teovent ; Sabidal ; ZYMA S.A.) and after intravenous infusion of aminophylline to eight healthy volunteers. Both drugs were administered in the morning (10 a.m.) and on a separate occasion in the evening (10 p.m.) after a 12 h period of fasting. After oral administration of a dose of 540 mg theophylline, the drug was steadily absorbed, both during day-time and during night-time. In some subjects absorption was slower in the evening. Maximum theophylline plasma concentrations were reached after 3.3 +/- 0.4 h (mean +/- SD) and 3.9 +/- 1.4 h respectively (not significantly different p greater than 0.05). The maximum plasma concentrations were almost identical after administration in the morning and in the evening (12.6 +/- 3.3 mg X l-1 and 13.1 +/- 1.4 mg X l-1 respectively). There was also no significant difference (p greater than 0.05) between the areas under the plasma concentration-time curves after oral and intravenous administration, both at day-time and at night-time. This finding indicates complete bioavailability of the sustained release tablets on both occasions. After administration of the tablets in the morning the plasma concentration 12 h post dosing was significantly lower than after administration in the evening: c1 12 accounted for 6.0 +/- 2.0 mg X l-1 after intake at 10 a.m. and for 7.9 +/- 2.1 mg X l-1 after ingestion at 10 p.m. (p less than 0.01). A similar observation was done after intravenous administration of the drug: c12 was 6.6 +/- 1.6 mg X l-1 after starting the infusion in the morning and 8.0 +/- 1.8 mg X l-1 after infusing the drug in the evening (p less than 0.01). This phenomenon could be explained by the finding of a significantly prolonged half-life of theophylline during night-time, provided that the plasma concentrations were in the range of 5 to 15 mg X l-1 (which coincides approximately with the therapeutic range of the drug).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical pharmacokinetic comparison of two indometacin containing suppositories with different vehicula.

A single dose each of two brands of indometacin (INN; in some pharmacopoeias called indomethacin) containing suppositories, made with different vehicula , was administered rectally - in a cross over design - to ten healthy volunteers. Product A ( Dolcidium ) was made of a new waxy excipient which emulsifies at body temperature; product B was a leading brand of indometacin containing suppository, made of a hydrophilic polyethyleneglycol basis, which dissolves in body fluid. Plasma indometacin concentrations were measured frequently during a period of 9 h after dosing. Both products showed rather consistent absorption profiles. The maximum plasma indometacin concentration after administration of the product A 50 mg suppository was found after 62 +/- 18 min (mean +/- S.D.), and measured 2.0 +/- 0.5 mg X l-1. After dosing with the reference product those values were 66 +/- 21 min and 1.8 +/- 0.4 mg X l-1, respectively. The area under the plasma indometacin concentration-time curve was found to be 384 +/- 130 mg X l-1 X min for product A 50 mg suppositories and 372 +/- 62 mg X l-1 X min for the reference product. This results in a relative bioavailability of the product A 50 mg suppositories of 1.02, after correction for actual amount of indometacin in each dosage form. None of the above mentioned pharmacokinetic parameters were statistically significantly different (p greater than 0.05), indicating bioequivalence of the two products.

Plasma indomethacin assay by reversed-phase ion pair high pressure liquid chromatography.

A new rapid, selective and sensitive high pressure liquid chromatographic (HPLC) assay for indomethacin in plasma is described. The method involves precipitation of proteins with perchloric acid, followed by dichloromethane extraction using flurbiprofen as an internal standard. The organic solvent was evaporated and the residue dissolved in a water-methanol (2 + 3) phosphate buffer mixture with an apparent pH of 6.8. Aliquots of 100 microliters were injected automatically into the chromatograph. The separation of indomethacin was achieved on a reversed phase (C18, 10 micron) column with a mobile phase consisting of 65% (vol/vol) methanol in water solution of apparent pH 6.8 containing tetrabutylammonium hydrogensulfate as an ion pairing agent. Quantitation of indomethacin was performed by UV detection at 235 nm. At a 2.0 mg X l-1 concentration of indomethacin in plasma the analytical recovery was 82.9 +/- 3.4% (n = 7), the intra-day variability (CV) was 3.6% (n = 7) and the inter-day variability (CV) was 11.0% (n = 7). The calibration curve was linear (typical r-values greater than 0.990) in the range of plasma concentrations as usually found during indomethacin therapy (up to 6 mg X l-1). The limit of sensitivity is 0.025 mg X l-1. The metabolites O-desmethylindomethacin and O-desmethyldeschlorobenzoylindomethacin did not interfere with the method. The capacity of an analyst using this method with automated injection and peak integration is about forty samples in duplicate per day. The applicability of the method for pharmacokinetic studies is demonstrated.