[Femtosecond laser ablation and scanning microscopy of the internal retinal limiting membrane: an experimental study].

The investigation was undertaken to study whether femtosecond laser ablation and microscopy might be used in the internal retinal borderline membrane. Ablation of internal limiting membrane preparations removed using or not using indocyanine green was made by a low-energy femtosecond laser. Examination of the preparations by laser and electron microscopy revealed precision laser cuts of the internal retinal borderline membrane. The use of indocyanine green during laser ablation reduced laser irradiation parameters as compared to the dye not being applied. Low-energy femtosecond lasers enable precision contactless ablation of the internal borderline membrane to be carried out without collateral damage to the adjacent tissue. The parameters of laser impulses, particularly low ones used in the ablation of indocyanine green-stained preparations, prove the photosensitizing effect of the dye.

Identification of the major metabolite of prostacyclin and 6-ketoprostaglandin F1 alpha in man.

Human volunteers were infused with 3H- and 2H-labeled prostacyclin or 3H-labeled 6-ketoprostaglandin F1 alpha and, in separate experiments, with the unlabeled prostanoids. The urine was purified by different chromatographic steps and finally separated into several fractions by high-performance liquid chromatography. The major fractions contained 20.5 and 23.0% of the eluted readioactivity for the metabolites of prostacyclin and 6-ketoprostaglandin F1 alpha, respectively. The structure of both metabolites was identified by gas-liquid chromatography-mass spectrometry as dinor-6-ketoprostaglandin F1 alpha. It is concluded that the major metabolite of prostacyclin and 6-ketoprostaglandin F1 alpha in man is dinor-6-ketoprostaglandin F1 alpha.

Simultaneous expression of leukocyte-type 12-lipoxygenase and reticulocyte-type 15-lipoxygenase in rabbits.

In rabbit reticulocytes an arachidonic acid 15-lipoxygenase (15-LOX) is expressed at high yield. Rescreening a rabbit reticulocyte cDNA library for alternative 15-LOX transcripts, a full length cDNA which encodes a novel lipoxygenase was isolated. The predicted amino acid sequence of this enzyme shared a high degree (99%) of identity with the reticulocyte-type 15-lipoxygenase. Among the six amino acid residues different in both enzymes a Phe-Leu exchange was detected at position 353. Recently, site-directed mutagenesis studies have revealed that this amino acid exchange converts a 15-lipoxygenase to a 12-lipoxygenase. In fact, when the novel enzyme was expressed in Escherichia coli, mainly 12-lipoxygenation of arachidonic acid was observed. The recombinant enzyme exhibited a rather broad substrate specificity. Various C-18 and C-20 polyenoic fatty acids and even complex substrates such as biomembranes were effectively oxygenated. Thus, the novel enzyme may be classified as leukocyte-type 12-lipoxygenase. Genomic polymerase chain reaction of the 3' region of the leukocyte-type 12-lipoxygenase gene indicated that introns 10 to 13 differed to about 10% from the corresponding sequences of the 15-lipoxygenase gene although their size and the intron-exon organization were very similar. In the 3'-untranslated region of the novel mRNA a C+U-rich, 20-fold repetitive element was found which appears to be highly related to the differentiation control element of the 15-lipoxygenase mRNA. Activity assays with a variety of cells and tissues prepared from normal rabbits suggested that only peripheral monocytes abundantly express the enzyme, suggesting a tissue-specific regulation of gene expression. These data indicate for the first time the co-expression of two separate genes for a reticulocyte-type 15-lipoxygenase and for a leukocyte-type 12-lipoxygenase in one species. This is of importance for the implication of both enzymes in red blood cell development and atherogenesis.

Indomethacin but not aspirin increases plasma lithium ion levels.

The pharmacokinetic drug interactions between lithium sulfate and the nonsteroidal anti-inflammatory drugs (NSAIDs) indomethacin and aspirin were studied in ten normal female volunteers restricted to 150-mEq/day of sodium. Indomethacin decreased renal lithium ion elimination by 23% and caused a 40% increase in steady state plasma lithium ion levels. In contrast, aspirin had no effect on plasma lithium ion levels and increased renal lithium ion elimination by only 6%. Renal prostaglandin E2 excretion was suppressed by 50% to 60% of control levels by indomethacin and by 65% to 70% by aspirin. A clinically important drug interaction with the risk of lithium intoxication can occur between lithium salts and indomethacin. However, aspirin did not affect steady state plasma levels of lithium ion and thus may be preferable for antirheumatic treatment of patients undergoing long-term therapy with lithium salts. Frequent monitoring of plasma lithium ion levels is absolutely necessary in patients receiving both lithium salts and NSAIDs.

Genetic and antigenic characterization of Bungowannah virus, a novel pestivirus.

Bungowannah virus, a possible new species within the genus Pestivirus, has been associated with a disease syndrome in pigs characterized by myocarditis with a high incidence of stillbirths. The current analysis of the whole-genome and antigenic properties of this virus confirms its unique identity, and further suggests that this virus is both genetically and antigenically remote from previously recognized pestiviruses. There was no evidence of reactivity with monoclonal antibodies (mAbs) that are generally considered to be pan-reactive with other viruses in the genus, and there was little cross reactivity with polyclonal sera. Subsequently, a set of novel mAbs has been generated which allow detection of Bungowannah virus. The combined data provide convincing evidence that Bungowannah virus is a member of the genus Pestivirus and should be officially recognized as a novel virus species.

Elevation of steady-state diazepam levels by cimetidine.

The effect of cimetidine (1000 mg/day) on steady-state diazepam (5 mg/day) kinetics was investigated in six healthy subjects. During placebo-controlled treatment for 11 days, trough steady-state plasma levels were 130 +/- 33 ng/ml and steady-state concentration averaged 185 +/- 57 ng/ml (mean +/- SD). During concomitant treatment with diazepam and cimetidine these concentrations rose to 194 +/- 52 ng/ml and 255 +/- 46 ng/ml (P less than 0.002). The 40% to 50% increase was due to reduction (P = 0.026) of total body clearance from 20.9 +/- 9.5 ml/min (control) to 14.0 +/- 3.0 ml/min (with cimetidine). Diazepam elimination half-life was also prolonged (P = 0.02, from 39.5 +/- 16.6 hr to 101 +/- 58.1 hr) by cimetidine.

Effects of diclofenac on lithium kinetics.

The influence of the prostaglandin (PG) synthesis-inhibiting, nonsteroidal anti-inflammatory drug (NSAID) diclofenac on lithium kinetics was studied in five normal women on a 150-mEq sodium diet. Diclofenac decreased lithium renal clearance by 23% (P - 0.002) and increased lithium plasma levels by 26% (P - 0.001). Renal PG synthesis was suppressed by 53% of control values. These data show a clinically important drug interaction, possibly on the basis of a PG-dependent mechanism, with the risk of lithium intoxication for patients treated with lithium salts and NSAIDs.

Effects of cimetidine and ranitidine on steady-state propranolol kinetics and dynamics.

The influence of cimetidine (1000 mg daily, one day oral pretreatment) and ranitidine (300 mg daily by mouth, 1 and 6 days pretreatment) on steady-state propranolol (160 mg sustained-release capsule, once daily) plasma levels (Psss) and dynamic beta-blocker effects was assessed by bicycle ergometer exercise and isoproterenol sensitivity test in five normal subjects. During the 3 hr of the dynamic tests Psss were elevated from 25% to 67% by cimetidine, whereas Pss was unchanged by ranitidine. The estimated hepatic blood flow (EHBF) as calculated from indocyanine green (ICG) plasma clearance was only slightly reduced by 15 +/- 23% (mean +/- SD, n = 4) after one oral dose of 150 mg ranitidine and showed substantial intersubject variability. Dynamic parameters, like propranolol-induced heart rate and blood pressure changes under physical exercise or during the isoproterenol sensitivity test, were not influenced by ranitidine or cimetidine. Since our study was performed on normal subjects with relatively low propranolol doses these results do not rule out the risk of severe reinforcement of beta-adrenergic receptor blocking effects if propranolol and cimetidine are taken together by patients.

Chronopharmacokinetic study with prolonged infusion of midazolam.

Physiological and temporal variation in the disposition of midazolam has been reported. In order to delineate the underlying mechanisms of these alterations, we infused in 5 healthy male volunteers for 26 hours midazolam at a rate of 0.025 mg/kg/h preceded by a bolus of 0.05 mg/kg. Thus, steady-state conditions were rapidly achieved. Plasma levels of midazolam were monitored on a 2-hourly basis during this period. In addition, the pharmacodynamic response to the new sedative/hypnotic benzodiazepine was characterised by a pencil tracking test, sedation index formed from visual analogue scales, and choice reaction time. In all subjects, small (4 to 16%) but clinically irrelevant fluctuations of steady-state plasma concentrations around 45 ng/ml were observed. During the night-time (11pm to 7am) plasma concentrations were slightly (p = 0.074) higher than during the daytime. Total plasma clearance varied from 563 to 823 ml/min. Plasma protein binding of midazolam was time independent. Since in only 1 of 5 subjects was a circadian rhythm observed, fluctuations in plasma midazolam concentrations under controlled and constant conditions are probably not of clinical significance.

Pharmacodynamic interaction between midazolam and a specific benzodiazepine antagonist in humans.

The pharmacodynamic interaction between midazolam and the specific benzodiazepine antagonist Ro 15-1788 has been investigated in six healthy male volunteers. Hypnotic steady-state concentrations of midazolam (55 +/- 11 ng/mL; mean +/- SD) have been achieved rapidly by an intravenous bolus of 0.07 mg/kg and maintained by an individual but constant infusion rate of 0.025 to 0.04 mg/kg/hr for eight hours. Following a two-hour control period, the antagonist (2.5 mg) or the solvent were injected double-blind in random order. Three hours later, the other medication was administered. Whereas plasma levels of midazolam remained constant throughout the complete eight-hour trial (Clearance = 670 +/- 96 mL/min) concentrations of Ro 15-1788 declined rapidly with an elimination half-life between 0.7 and 1.8 hours and a total plasma clearance of 702 +/- 235 mL/min. Concentrations of Ro 15-1788 approached the analytic limit of 2 ng/mL within three hours. The pharmacodynamic response to midazolam and the antagonist was assessed by a sedation index using visual analogue scales, reaction time (RT) measurements, and transformed Fourier analysis of the power spectrum of the recorded electroencephalogram (EEG). About 30 to 45 seconds following the injection of Ro 15-1788, hypnotic action of midazolam was completely reversed as visualized by return to alpha rhythm in the EEG, shortening of prolonged RT, and normalization of the elevated sedation index. The antagonistic action lasted for about two to three hours. The abrupt arousal from sleep was not associated with any unpleasant sensations, however, three subjects experienced a profound perspiration for about ten minutes following the injection of Ro 15-1788.(ABSTRACT TRUNCATED AT 250 WORDS)

Opipramol for the treatment of somatoform disorders results from a placebo-controlled trial.

Although somatoform disorders are highly prevalent, so far there is no established pharmacological treatment. Opipramol is a psychopharmacon widely prescribed in Germany. Early trials with opipramol showed the drug's effectiveness in anxiety states coupled with somatic complaints. Therefore, the efficacy of opipramol in somatoform disorders was evaluated using adequate clinical trial methods. A multicentre, randomized, 6-week, placebo-controlled clinical trial was performed in a total of 200 patients suffering from somatoform disorders according to ICD-10. In the main outcome criterion, the somatic subscore of the Hamilton Anxiety Scale, and in nearly all other outcome criteria opipramol (200 mg/day) was statistically more effective than placebo. A similar number of adverse events was noted in both groups. The results of this first-placebo-controlled study in somatoform disorders suggest efficacy of opipramol in this indication but need replication.

Application of the photoionization detector for the determination of ethanol in aqueous solutions and human breath.

A determination of ethanol is described, which is based on a purging system in conjunction with a photoionization detector. With that system a fast and reliable determination of ethanol in aqueous solutions is possible. The system has been used for the analysis of wine. The 3delta-detection limit has been 0.005% ethanol, the relative standard deviation 4.8 to 6.0% and the time constant of the entire analytical system 20 s. The photoionization detector has been also applied to the analysis of artificial and genuine human breath. A comparison with gas-chromatography and non-dispersive IR-detection has been proven the reliability of results.

Epidemiological data on drug use during pregnancy in Thuringia, East Germany, 1993.

An international collaborative WHO-study on drug use in pregnancy of 1987 involving 300 puerperae from Thuringia, East Germany (the former GDR), has partly shown great differences in drug use habits between the countries which had participated on the study. In 1993--after the radical change on the socioeconomic situation in East Germany by the reunification of Germany leading also to changes in health service--an update of the East German data was carried out by repeating the investigation in the same Thuringian region as in 1987. Whereas drug therapy of chronic diseases in pregnancy and drug administration under delivery were widely similar in both investigations, we found a marked increase in drug use in case of illness in the course of pregnancy before admission to hospital for delivery but also in the treatment of nursing women. The differences can be partly put down to socioeconomic development. Because of the continuously enlarging drug market on the one hand and a small data basis on drug risks and side-effects for unborn life on the other hand, a large screening on drug exposition in pregnancy including recording of newborns' data ought to be performed.

Severe hypoglycemia in an elderly patient treated with metformin.

UNLABELLED: The following case of severe hypoglycemia was reported during a systematic evaluation of hospital admissions caused by adverse drug reactions (supported by BfArM). HISTORY AND FINDINGS ON ADMISSION: A 79-year-old diabetic woman was admitted to hospital in a stuporous and unresponsive state. The initial physical examination revealed no other abnormal findings. Serum blood glucose was found to be 2.0 mmol/l and HbA1c was 4.6%. The patient had been started on antidiabetic therapy with metformin 2 months earlier. Treatment with other drugs being taken at that time, an ACE inhibitor, an NSAID and nitrofurantoin, remained unchanged. DIAGNOSIS, TREATMENT AND FOLLOW-UP: Laboratory tests excluded lactic acidosis and renal insufficiency. Cerebral computed tomography findings were normal. The patient improved dramatically following administration of glucose. Other laboratory findings confirmed the diagnosis of hypoglycemia. Blood glucose concentrations ranged between 4.0 and 10.0 mmol/l in the subsequent days and the patient could be discharged in full health. CONCLUSIONS: Drug-induced hypoglycemia is possible even in diabetics not receiving insulin or oral antidiabetic agents increasing insulin secretion. The risk of drug-induced hypoglycemia should be particularly considered when drugs containing blood glucose-lowering components are combined. Metformin does not usually cause hypoglycemia when administered as monotherapy. We suspected that hypoglycemia in this patient was caused by additional blood glucose-lowering effects of the ACE inhibitor and the NSAID possibly combined with a suboptimal nutrition. The indications for metformin administration undergo critical scrutiny.

Pattern of outpatient drug therapy in diabetics admitted to hospital--preliminary results.

UNLABELLED: The prevalence of outpatient treatment with various drug groups is significantly higher in diabetics than in non-diabetic control patients. In addition to the specific diabetes-related prescriptions, diabetics were more frequently treated with drugs acting on the alimentary tract or used in metabolic disorders (ATC code A), drugs used in disorders of the blood and blood-forming organs (ATC B), cardiovascular system (ATC C), musculo-skeletal system (ATC M) and nervous system (ATC N)-- resulting in markedly higher outpatient costs in this patient group. Objective of this investigation was to analyze the pre-hospital prescription pattern of diabetics and non-diabetic controls at the time of admission to hospital. METHOD: A sample survey of a total of 189 general medical and 68 surgical admissions involving diabetics and 676 and 143 non-diabetic control patients corresponding in age, sex and main diagnosis--were analyzed with regard to selected medical and demographic characteristics and pharmacotherapy. RESULTS AND DISCUSSION: The prevalence of non-diabetic drug treatment in diabetics was highest for ATC C (87.8% and 69.1%), ATC A (40.7% and 27.9%; without A10) and ATC B (39.2% and 29.4%) in internal and surgical admissions, respectively. A substantially higher prevalence was found for ATC groups B and C in diabetics and controls admitted to medical wards than in epidemiological prescription analyses. CONCLUSION: Data indicate that the need for treatment with cardiovascular drugs and drugs used to treat disorders of the blood and blood-forming organs may be associated with a higher risk of hospitalization in general medical wards.

Pathology of congenital metatarsus varus and its relationship to other congenital deformities of the foot.

Congenital metatarsus varus may be regarded as a deformity caused by a dislocation and in that respect is similar to congenital clubfoot and vertical talus but not to calcaneovalgus. The dislocation causes adaptive bone changes as well as secondary contracture of the soft tissues. That the dislocation in the forepart of the foot may occur in a maximally dorsiflexed foot also may explain the valgus position of the hindfoot. The secondary changes in bone and soft tissue may explain the lack of spontaneous recovery and the difficulties in effecting correction in severe cases. It is still not possible to explain why the dislocation arises.

Subacute liver necrosis after experimental infection with rabbit haemorrhagic disease virus (RHDV).

Rabbit haemorrhagic disease (RHD) is usually peracute to acute, while subacute to chronic disease is rare. This paper describes gross and histopathological findings in four out of 20 rabbits aged 14 weeks, experimentally infected with one of two German field isolates of RHD virus. Eight rabbits survived the infection for 10 days and were killed after four of them, infected with 100 to 10 000 haemagglutination units, had started to develop progressive jaundice. Histopathologically, icteric livers showed severe subacute centrilobular bridging necrosis with calcification, and proliferation of periportal hepatocytes and bile ducts. Positive-strand RHDV RNA was detected by in-situ hybridization, mainly in periportal macrophages. Loss of the normal hepatic architecture, reparation (fibrosis) and hepatocellular regeneration, together with moderate inflammatory reaction, are signs of liver cirrhosis. These signs, observed in young rabbits given small doses of RHD virus, are interpreted as an unusual outcome of experimental inoculation.

Renal excretion and renal tubular transport of p-aminohippurate (PAH) in methimazole treated, hypothyroid rats of different ages.

Thyroid hormone deficiency following treatment with methimazole for 7 days does not reduce PAH secretion in renal tubular cells as expected from data in thyroid hormone treated rats. This treatment with methimazole causes an increase in renal excretion of PAH in rats of various age groups, statistically significant in 5-, 10- and 20-day-old rats. In 20-day-old, methimazole treated rats the increase in renal excretion of PAH is obviously caused by a higher transport rate in renal tubular cells, proved also in 33-day-old rats. An increased filtered fraction of PAH in 5- and 10-day-old rats could be the reason for the rise in renal excretion of PAH after repeated treatment with methimazole. The mechanism of renal effects of methimazole treatment remains unclear.

Intraarticular lymphoscintigraphy of the human knee joint: a preliminary study.

Intraarticular (knee) lymphoscintigraphy using 99mTc-nanocoll was performed in five patients with chronic synovitis. Scintigrams from the anterior and lateral view of the knee and of the iliac region were taken 1, 2, 4, and 22 hours after injection. The inguinal and iliac lymph nodes uniformly visualized in about 2 hours. Based on radioactivity in regional lymph nodes measured at prescribed time intervals, we were able to quantify lymph drainage from the knee joint. Lymphoscintigraphy is without complication and discomfort and is potentially useful to study synovial fluid reabsorption in joint diseases.

Practice effect of volunteers in repeated psychometric testing. How to handle this intervening variable in clinical pharmacology studies?

Performance in psychometric tests may show a practice effect with repeated testing. Ideally, a plateau of efficiency should be reached prior to first drug intake. In order to assess the period of familiarization in a multiple choice reaction task (MCRT) 17 healthy subjects practiced the test up to 36 times in the drug free run-in period of 2 trials. A tentative "inclusion criterion" was used in 7 subjects to decide whether their learning phase could be regarded as being finished. Seven to 20 training sessions were required for a first rapid learning phase. There were remarkable differences in the absolute performance of the subjects and in the time course of their practice effect. However, the time course of the learning phase was not dependent on the absolute performance level. By means of the tentative "inclusion criterion" it was possible to reject a subject with a low but highly variable performance. However, it was not stringent enough to indicate the final plateau of efficiency. More "drug free" data concerning the practice effect should be published to enable the users of psychometric tests to make a reasonable selection according to their needs and to help them design their trials properly.