Isolation of bacteria from toxic dinoflagellate Alexandrium minutum and their effects on algae toxicity

Attempts were made to isolate the bacteria from toxic dinoflagellate Alexandrium minutum T1 and to study the effect of these bacteria on the growth and toxicity of A. minutum T1. It was found that intracellular bacterial species including Pasteurella haemolytica, Pseudomonas vesicularis, and Sphingomonas sp., and extracellular bacterial species including Pasteurolla pneumotropica, Morganella wisconsensis, Flavobacterium oryzihabitans, Pseudomonas pseudomallei, and Sphingomonas sp. All of them were cultured and determined to have non-PSP-producing ability. The maximum cell number of A. minutum cultured without isolated bacteria was higher than that cultured with isolated bacteria. The total toxicity of A. minutum cultured with bacteria was similar to that of A. minutum T1 cultured without bacteria from lag phase to stationary phase, but it was lower after stationary phase. The growth of A. minutum T1 cultured without antibiotics was also better than that cultured with antibiotics. The total toxicity of A. minutum cultured without antibiotics was higher than that of A. minutum cultured with antibiotics. However, the cell toxicity of A. minutum did not decrease even if the culture medium was added with antibiotics.

Influence of environmental and nutritional factors on growth, toxicity, and toxin profile of dinoflagellate Alexandrium minutum

The toxic dinoflagellate Alexandrium minutum T1 was isolated from southern Taiwan in February 1996, grown under various environmental and nutritional conditions, and then examined for growth, toxicity, and toxin profile. It was found that the optimal environmental conditions for cell growth and toxin production of A. minutum T1 was as follows: temperature 25 degrees C, pH 7.5, light strength 120 microEm(-2) s(-1), and salinity 15 ppt. The optimal level of nutrients supplemented in the 50% natural seawater medium was as follows: phosphate 0.002%, nitrate 0.01%, cupric ion 5.0 ppb, ferric ion 270 ppb and humic acid free. Both cell toxicity and total toxicity reached the maximum level at the post-stationary growth phase and decreased quickly. The toxic components of A. minutum T1 were assayed by high performance liquid chromatography, and found to be gonyautoxin (GTX) 1-4 only. Among these four toxin components, toxins GTX 1 and 4 were the predominant components throughout the growth curve when the cells were grown in the optimal environmental and nutritional conditions. But toxins GTX 2 and 3 increased when the cells were cultured in high salinity medium.

Unilateral vocal cord paralysis following endotracheal intubation--a case report

A 41-year-old man of ASA physical status class I was scheduled to receive the video-assisted thoracoscopic T2 sympathectomy for hyperhidrosis palmaris. The elective surgery was performed smoothly under general anesthesia with endotracheal intubation. However, the patient complained of hoarseness in the postoperative period. A stroboscopic examination showed that the left vocal cord remained stationary in the paramedian position, signifying left vocal cord paralysis. In the case, we believed it was most likely that endotracheal intubation might be responsible for the unilateral vocal cord paralysis. The possible cause was that during placement or thereafter during positioning, the endotracheal tube was malposed or slipped upward, rendering its inflated cuff to rest against the vocal cords. Another reason was that the cuff which was over inflated made the vocal cords under constant pressure. Both conditions may cause damage to the anterior branch of the recurrent laryngeal nerve. We also discussed the general management and prophylaxis for the unilateral vocal cord paralysis.

[Study model for isolated heart perfusion combined with NMR technique]

Some improvements made to overcome the difficulty in the long distance perfusion, temperature maintenance, oxygen supply and the recollection of perfused fluid were described in our Langendorff perfusion in combination of NMR technique with which the rhythmic activity of isolated rat heart can be measured as long as 90 min.

Malariotherapy for HIV patients

The objective of this study was to determine whether HIV patients who undergo malariotherapy experience beneficial immunological change without iatrogenic complications. In an approved, prospective study, asymptomatic. HIV-positive patients were inoculated with P. vivax malaria and the malaria infection was allowed to run a predetermined course according to standard malariotherapy protocols and was cured with chloroquine. After termination of the malaria, the patients have been followed for 2 years with clinical and immunological monitoring. In the first two HIV-positive patients, CD4 counts rose significantly from pre-malaria measurements and remain at normal levels 2 years later without further treatment of any kind. During this time, the patients remained clinically well. An additional six HIV-positive patients were treated with malariotherapy and have remained clinically well during the first 6 months after treatment. These initial studies demonstrate malariotherapy results in an increase in CD4 counts of HIV-positive patients. Furthermore, these increases persist beyond the presence of malaria, for at least 2 years.

[Effect of hedgehog hydnum on the delay of fatigue in mice]

Two groups of mice were fed with either hedgehog hydnum powder or extract for sixty days. For the assay of fatigue, the activity of serum lactate dehydrogenase, the serum urea nitrogen content, blood lactic acid, hepatic and muscular glycogen, and the physical stamina of the mice were determined. The activity of serum lactate dehydrogenase and the hepatic and muscular glycogen content in the experimental mice were evidently higher than that in the control mice (P < 0.05 or P < 0.01). After exercise, the increase in blood lactic acid and serum urea nitrogen in the experimental mice was significantly lower than that in the control mice (P < 0.05 or P < 0.01), but the rate of elimination of blood lactic acid in the experimental mice was significantly higher than that in the control mice (P < 0.05). In the physical stamina swimming, the experimental mice drowned after a longer period of time than the control mice (P < 0.05). In conclusion hedgehog hydnum had a significant effect on raising physical stamina and delaying fatigue in mice.

Molecular mapping of wheat: major genes and rearrangements in homoeologous groups 4, 5, and 7

A molecular-marker linkage map of hexaploid wheat (Triticum aestivum L. em. Thell) provides a framework for integration with teh classical genetic map and a record of the chromosomal rearrangements involved in the evolution of this crop species. We have constructed restriction fragment length polymorphism (RFLP) maps of the A-, B-, and D-genome chromosomes of homoeologous groups 4, 5, and 7 of wheat using 114 F7 lines from a synthetic X cultivated wheat cross and clones from 10 DNA libraries. Chromosomal breakpoints for known ancestral reciprocal translocations involving these chromosomes and for a known pericentric inversion on chromosome 4A were localized by linkage and aneuploid analysis. Known genes mapped include the major vernalization genes Vrn1 and Vrn3 on chromosome arms 5AL and 5DL, the red-coleoptile gene Rc1 on 7AS, and presumptively the leaf-rust (Puccinia recondita f.sp. tritici) resistance gene Lr34 on 7DS and the kernel-hardness gene Ha on 5DS. RFLP markers previously obtained for powdery-mildew (Blumeria graminis f.sp. tritici) resistance genes Pm2 and Pm1 were localized on chromosome arms 5DS and 7AL.

Stroke-like complication after abdominal surgery: a case report of chronic subdural hematoma

An 81-year-old patient who developed consciousness change and progressive right limb weakness after low abdominal surgery is reported. Brain computed tomography scan showed a left-sided chronic subdural hematoma; appropriate management was instituted immediately. This case is a reminder of the possibility of chronic subdural hematoma in elderly patients who may develop stroke-like symptoms after non-neurosurgical procedures.

Professional behaviour of medical school graduates: an analysis

Recent graduates (1989-1990) of a traditional school of Chinese medicine were assessed by observers using a 10-item scale for professional behaviour in the non-cognitive realm. Overall, 10.7% of the graduates had low ratings on this scale. Of those who scored in the top two quartiles on this scale, 71.4% reported that 'Professional ethics' was the key determinant of their professional behaviour, whereas legal concerns were the prime motivator for only 3.6% of the top scorers. It was also found that students' scores in the medical ethics course correlated with their professional behaviour score to a statistically significant degree.

Total synthesis of yeast alanine transfer ribonucleic acid

By a combination of chemical and enzymatic methods, small oligonucleotides with lengths varying from 2 to 8 nucleotides were synthesized from mononucleotides. The small oligonucleotides were then ligated with T4 RNA ligase into six large oligonucleotides (9 to 19 nucleotides long) which were further ligated to form two half molecules with 35 and 41 nucleotides respectively. Finally, the two synthetic half molecules were annealed and ligated to obtain the whole molecule of yeast alanine tRNA (tRNAAlay). Prior to this, two semi-syntheses were performed, i.e. ligation of the synthetic 5'-half molecule with the natural 3'-half molecule and that of the natural 5'-half molecule with the synthetic 3'-half molecule. Both the semi-synthetic tRNAAlay and the synthetic tRNAAlay occupy the same position as the natural tRNAAlay after electrophoresis on a 20% polyacrylamide gel. They have the same chemical composition (containing 9 modified nucleotides of 7 different species) and structure as the natural tRNAAlay and are biologically active, i.e. accepting and transferring alanine into proteins in a cell-free protein synthesizing system, the accepting activity of the synthetic product is 52-66% of that of the natural tRNAAlay and 91-106% of that of the reconstituted product of the two natural half molecules. The incorporation activity of alanine into proteins of the synthetic 3H-alanine tRNAAlay is 63%, corresponding to 91% of that of the natural tRNAAlay and 115% of that of the reconstituted product of the two natural half molecules. To the best of our knowledge, this is the first time that a natural RNA with biological activity is synthesized.