Antimycin A-producing nonphytopathogenic Streptomyces turgidiscabies from potato.

AIM: To detect if substances with mammalian cell toxicity are produced by Streptomyces turgidiscabies and Streptomyces scabiei isolated from potato scab lesions. METHODS AND RESULTS: In vitro cultures of phytopathogenic and nonphytopathogenic strains of S. scabiei and S. turgidiscabies, isolated from scab lesions of potato tubers originating from nine different cultivars from Finland and Sweden, were tested for toxicity using the rapid spermatozoan motility inhibition assay, previously shown useful in the detection of many different Streptomyces toxins and antimicrobial compounds. Purified toxins were used as reference. Three nonphytopathogenic strains of S. turgidiscabies were found to produce antimycin A when cultured on solid medium. CONCLUSIONS: Boar sperm-motility-inhibiting substances are produced by strains of S. turgidiscabies and S. scabiei. The most powerful inhibitory substance, produced by three nonphytopathogenic S. turgidiscabies strains, was identified as antimycin A. The phytotoxic compounds thaxtomin A and concanamycin A did not inhibit sperm motility even at high doses. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of antimycin A-producing Streptomyces strains, nonpathogenic to potato, was unexpected but important, considering the high mammalian toxicity of this cytochrome bc-blocking antibiotic.

In vitro assay for human toxicity of cereulide, the emetic mitochondrial toxin produced by food poisoning Bacillus cereus.

The in vitro boar spermatozoon test was compared with the LC ion trap MS analysis for measuring the cereulide content of a pasta dish, implemented in serious emetic food poisoning caused by Bacillus cereus. Both assays showed that the poisonous food contained approximately 1.6 microg of cereulide g(-1) implying the toxic dose in human as < or =8 microg kg(-1) body weight. The threshold concentration of cereulide provoking visible mitochondrial damage in boar sperm exposed in vitro was 2 ng of cereulide ml(-1) of extended boar sperm. The same threshold value was found for cereulide extracted from the food and from the cultured bacteria. This shows that other constituents of the food did not enhance or mask the effects of cereulide. Exposure of four human cell lines (HeLa, Caco-2, Calu-3 and Paju) to cereulide showed that the threshold concentration for the loss of mitochondrial membrane potential in human cells was similar to that observed in boar sperm. Human cells and boar sperm were equally sensitive to cereulide. The results show that boar spermatozoan assay is useful for detecting cereulide concentrations toxic to humans. Spermatozoa in commercially available extended fresh boar and cryopreserved bull semen were compared, boar sperms were 100 times more sensitive to cereulide than bull sperms.

Hyaluronate and large molecular weight proteoglycans in synovial fluid from horses with various arthritides.

OBJECTIVE: To investigate the presence of large molecular weight (MW) proteoglycans (PG) and hyaluronate (HA) in synovial fluid (SF) from horses with various arthritides and from control joints. DESIGN: Horses with acute (< 2 weeks) or chronic (> 4 weeks) lameness were examined by clinical examination, intrasynovial anesthesia, radiography, arthroscopy, and SF analysis. Joints were grouped on the basis of diagnosis: acute traumatic arthritis, chronic traumatic arthritis (with a subgroup of degenerative joint disease), intra-articular fracture, and infectious arthritis. ANIMALS: 31 horses with arthritis and 9 control horses; altogether 43 SF samples were analyzed. PROCEDURE: High-performance liquid chromatography was used to assess HA and large MW PG in SF samples. RESULTS: A PG peak was identified in 8 of 23 SF samples of joints with chronic traumatic arthritis, 4 of which had no or minimal abnormal radiographic findings but mild articular cartilage fibrillation detected by arthroscopy, and in 3 joints with intra-articular fracture and 1 with resolving infectious arthritis, but not in joints with acute traumatic arthritis or in control joints. There was significant difference (P < 0.01) in mean (+/- SEM) HA concentration between control joints and joints with chronic traumatic arthritis (0.32 +/- 0.04 g/L; n = 9 vs 0.18 +/- 0.01 g/L; n = 23). CONCLUSION: Large MW PG fragments are released into equine SF in the course of articular disease and can be detected simultaneously with HA by high-performance liquid chromatography. CLINICAL RELEVANCE: The SF HA concentration can be used as diagnostic marker for chronic traumatic arthritis. However, SF PG or other marker cannot be used for diagnosing or monitoring degenerative joint disease.

Concentration and molecular weight distribution of hyaluronate in synovial fluid from clinically normal horses and horses with diseased joints.

High molecular weight (MW) hyaluronate (HA) is an integral part of synovial fluid (SF), regulating many important physiologic and pathophysiologic mechanisms. Many of its effects depend on, or are reflected in, the concentration and MW of HA. High-performance liquid chromatography was used to assess simultaneously the concentration and MW of HA in SF obtained from horses with various arthritides: acute traumatic arthritis; chronic traumatic arthritis, including degenerative joint disease (DJD); and infectious arthritis. The size-exclusion column was calibrated, using appropriate HA concentration and MW standards, before the high-performance liquid chromatographic assays of the SF samples. Calibration of the column disclosed that the maximal limit for MW estimation of HA was around 3 million. In control joints, MW of HA ranged from 2 to 3 x 10(6) (mean 2.5 x 10(6)) and did not differ significantly from MW of HA in SF from horses with acute or chronic traumatic arthritis (mean 2 x 10(6); range 1.5 to 3 x 10(6)). Interestingly, a small amount of HA of moderately high MW (approx 1 to 1.5 x 10(6)) was detected in chromatograms of SF from infected joints. This degree of polymerization of SF HA was significantly (P < 0.01) lower, compared with that for control joints. There was no difference in mean (+/- SD) concentration of HA between control joints and joints with acute or chronic traumatic arthritis (0.33 +/- 0.12 g/L vs 0.18 +/- 0.03 g/L or 0.23 +/- 0.12 g/L), indicating that SF HA concentration probably should not be used as a diagnostic marker for the condition.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of intermaxillary fixation on leukocyte zinc, serum trace elements and nutritional status of patients undergoing maxillofacial surgery.

Mononuclear cell (MNC), polymorphonuclear cell (PMNC) and serum zinc levels were studied in 17 oral surgical patients with intermaxillary fixation. Serum copper, iron, selenium and bromide concentrations were also measured together with common indices of nutritional status. Nine patients received nutritional counselling. Eight patients had, in addition, oral supplementation with a commercial formula. No changes in intracellular or serum zinc levels were seen during the study period. A statistically significant decrease was seen in mean body weight with subsequent changes in anthropometry. Maximal mean weight loss was 6.0 +/- 3.8% in control group and 3.8 +/- 2.7% in supplemental group. The impaired oral intake due to intermaxillary fixation does not interfere significantly with zinc status as estimated by MNC, PMNC or serum zinc levels. The reduction in body weight and anthropometric indices in the relatively short fixation period may be clinically significant in some patients. Supplementation with a commercial formula helps to maintain the nutritional status of these patients.

Propofol infusion for sedation in outpatient oral surgery. A comparison with diazepam.

An infusion of propofol was compared with intravenous boluses of diazepam as sedation for minor oral surgery under local anaesthesia in 12 healthy patients who had elective bilateral surgical extraction of lower third molars; the patients served as their own controls. Plasma catecholamine, vasopressin and cortisol concentrations were determined from repeated blood samples. The total administered dose of propofol was 3.93 (SD 1.34) mg/kg and of diazepam 0.28 (SD 0.07) mg/kg. No cardiovascular depression or airway problems occurred. Other side effects were also rare but some discomfort on injection was frequent with propofol. Recovery times were faster after propofol than after diazepam as assessed by the Maddox wing and visual analogue scales. Propofol also provided better amnesia compared to diazepam at the time of the extraction of the teeth. Eight of the 12 patients subjectively preferred propofol sedation. There was no hormonal stress response in either group.

A comparison of two sedative premedications for minor oral surgery under local anaesthesia.

Two commonly used drug combinations were studied as premedications before surgical 3rd molar removal under local anaesthesia. The study was randomized, crossover and double-blind in 12 patients. Our routine premedication for lengthy operations, consisting of diazepam 10 mg p.o. plus i.m. scopolamine 0.006 mg/kg and morphine 0.2 mg/kg, was compared with a combination of diazepam 10 mg p.o. plus metoprolol 50 mg p.o. The latter combination was expected to cause fewer central nervous system side effects and be more suitable for out-patient surgery. Drug levels in blood, physiological and biochemical indicators of operation-related stress, CNS side effects, and the patients' subjective preferences were monitored. Both combinations were equally accepted by the patients, but the diazepam/scopolamine/morphine combination caused clearly more side effects after discharge than diazepam/metoprolol. The operation-related haemodynamic changes and plasma catecholamine responses were similar after both premedications.

Local dental anaesthesia with lidocaine and adrenaline. Effects on plasma catecholamines, heart rate and blood pressure.

5 volunteers took part in this double-blind, cross-over study to evaluate the role of adrenaline 1:80,000 in lidocaine used in dental local anaesthesia on haemodynamics and the concentrations of catecholamines and their metabolites in plasma. The exogenous adrenaline statistically significantly elevated the heart rate (from 66 +/- 7 to 79 +/- 9 bpm), but did not affect systolic or diastolic blood pressure. Plasma adrenaline concentrations were increased more than 10-fold (from 0.02 +/- 0.02 to 1.0 +/- 0.3 nmol/l). We conclude that the adrenaline present in the local anaesthetic is a major source of adrenergic activation during minor oral surgery.