Cultivation of Microorganisms in the Cultural Medium Made from Squid Internal Organs and Accumulation of Polyunsaturated Fatty Acids in the Cells

The disposal and more efficient utilization of marine wastes is becoming increasingly serious. A culture media for microorganisms has been prepared from squid internal organs that are rich in polyunsaturated fatty acids (PUFAs). Both freshwater and marine bacteria grew well in this medium and some bacteria accumulated PUFAs in their lipids, suggesting uptake of exogenous PUFAs. Higher PUFA accumulations were observed in Escherichia coli mutant cells defective either in unsaturated fatty acid biosynthesis or fatty acid degradation, or both, compared to those without these mutations. Therefore, PUFA accumulation in cells can be improved by genetic modification of fatty acid metabolism in the bacteria. Squid internal organs would be a good source of medium, not only for marine bacteria but also for freshwater bacteria, and that this process may be advantageous to make efficient use of the fishery wastes and to produce PUFA-containing microbial cells and lipids.

Nursing care for dialysis patients in Japan

In Japan, the number of chronic renal failure patients requiring dialysis treatment is increasing by approximately 10,000 patients a year, totalling 229,538 or 1,801.2 patients per one million population at the end of December, 2002 according to the survey conducted by the Japanese Society for Dialysis Therapy. The primary disease is diabetic nephropathy (28.1% of patients), and with greater numbers of long-term and elderly patients, the incidence and severity of complications continue to increase. Dialysis units provide more diversified care, but budget cuts in health care make it difficult to secure sufficient personnel, and the workload on nurses has intensified. In this study, a survey of 157 out of 300 randomly selected dialysis facilities in Japan was made regarding nursing systems and nurses' concerns for medical care of dialysis patients.

Enhancement of polyunsaturated fatty acid production by cerulenin treatment in polyunsaturated fatty acid-producing bacteria

When docosahexaenoic acid (DHA)-producing Moritella marina strain MP-1 was cultured in the medium containing 0.5 microg cerulenin ml-1, an inhibitor for fatty acid biosynthesis, the cells grew normally, but the content of DHA in the total fatty acids increased from 5.9-19.4%. The DHA yield of M. marina strain MP-1 cells also increased from 4 to 13.7 mg l-1 by cerulenin treatment. The same effect of cerulenin was observed in eicosapentaenoic acid (EPA)-producing Shewanella marinintestina strain IK-1 grown in the medium containing 7.5 microg cerulenin ml-1, and the cerulenin treatment increased the EPA yield from 1.6 to 8 mg l-1. The use of cerulenin is, therefore, advantageous to increase the content of intracellular polyunsaturated fatty acids (PUFA) in particular PUFA-containing phospholipids in bacterial cells.

Centrosome hyperamplification and chromosomal damage after exposure to radiation

OBJECTIVE

In order to elucidate the effects of radiation on centrosome hyperamplification (CH), we examined the centrosome duplication cycle in KK47 bladder cancer cells following irradiation.

METHODS

KK47 cells were irradiated with various doses of radiation and were examined for CH immunostaining for gamma-tubulin.

RESULTS

Nearly all control cells contained one or two centrosomes, and mitotic cells displayed typical bipolar spindles. The centrosome replication cycle is well regulated in KK47. Twenty-four hours after 5-Gy irradiation, approximately 80% of irradiated cells were arrested in G2 phase, and at 48 h after irradiation, 56.9% of cells contained more than two centrosomes. Laser scanning cytometry performed 48 h after irradiation showed the following two pathways: (1) unequal distribution of chromosomes to daughter cells, or (2) failure to undergo cytokinesis, resulting in polyploidy. With mitotic collection, M-phase cells with CH could be divided into G1 cells with micronuclei and polyploidal cells. Fluorescence in situ hybridization analysis showed clear signs of chromosomal instability (CIN) at 48 h after irradiation. The present study had two major findings: (1) continual duplication of centrosomes occurred in the cell cycle-arrested cells upon irradiation, leading to centrosome amplification; (2) cytokinesis failure was due to aberrant mitotic spindle formation caused by the presence of amplified centrosomes. Abnormal mitosis with amplified centrosomes was detected in the accumulating G2/M population after irradiation, showing that this amplification of centrosomes was not caused by failure to undergo cytokinesis, but rather that abnormal mitosis resulting from amplification of centrosomes leads to cytokinesis block.

CONCLUSION

These results suggest that CH is a critical event leading to CIN following exposure to radiation.

EFFECTS OF MANGANESE SUPEROXIDE DISMUTASE NEBULIZATION ON PULMONARY FUNCTION IN AN OVINE MODEL OF ACUTE LUNG INJURY

Smoke inhalation injury is a major cause of morbidity and mortality in thermally injured individuals. There is evidence of increased oxygen free radical activity, e.g., superoxide, in association with smoke inhalation injury. Because superoxide dismutase converts the reactive superoxide radical to peroxide, we hypothesized that nebulization of manganese superoxide dismutase (Mn-SOD) into the airway might attenuate pulmonary dysfunction secondary to smoke inhalation injury. The present study was designed as a prospective, controlled, and randomized laboratory experiment to determine the effects of aerosolized Mn-SOD on lung fluid balance, as indexed by changes in pulmonary microvascular permeability, lung lymph flow (Q(L)), and gas exchange in an established and clinically relevant ovine model of smoke inhalation injury. Fifteen female Merino sheep were chronically instrumented with a femoral arterial, a Swan-Ganz, and a left atrial catheter. In addition, the right caudal mediastinal lymph node was cannulated to measure Q(L) (mL.h(-1)). Pneumatic occluders were placed around the right pulmonary veins for the determination of the reflection coefficient (sigma). After 7 days of recovery, sheep were randomly allocated to (a) an untreated control group (4 groups of 12 breaths of cotton smoke), (b) an injured group treated with nebulized Mn-SOD (5 mg/kg), and (c) an injured group that received only the vehicle (nebulized saline). Nebulization was performed 1 h and 12 h after smoke inhalation. Mn-SOD nebulization attenuated the increase in both filtration coefficient and sigma and significantly decreased lung tissue conjugated dienes. However, there were no differences in Q(L), PaO2/FiO2 ratio, and bloodless lung wet/dry weight ratio between groups. Although Mn-SOD nebulization attenuated the loss of protein, it failed to improve lung edema and pulmonary gas exchange, thereby limiting its clinical use.

Temperature adaptation in Dictyostelium: role of Delta5 fatty acid desaturase

Membrane fluidity is critical for proper membrane function and is regulated in part by the proportion of unsaturated fatty acids present in membrane lipids. The proportion of these lipids in turn varies with temperature and may contribute to temperature adaptation in poikilothermic organisms. The fundamental question posed in this study was whether the unsaturation of fatty acids contributes to the ability to adapt to temperature stress in Dictyostelium. First, fatty acid composition was analysed and it was observed that the relative proportions of dienoic acids changed with temperature. To investigate the role of dienoic fatty acids in temperature adaptation, null mutants were created in the two known Delta5 fatty acid desaturases (FadA and FadB) that are responsible for the production of dienoic fatty acids. The fadB null mutant showed no significant alteration in fatty acid composition or in phenotype. However, the disruption of fadA resulted in a large drop in dienoic fatty acid content from 51.2 to 4.1 % and a possibly compensatory increase in monoenoic fatty acids (40.9-92.4 %). No difference was detected in temperature adaptation with that of wild-type cells during the growth phase. However, surprisingly, mutant cells developed more efficiently than the wild-type at elevated temperatures. These results show that the fatty acid composition of Dictyostelium changes with temperature and suggest that the regulation of dienoic fatty acid synthesis is involved in the development of Dictyostelium at elevated temperatures, but not during the growth phase.

Isolation, identification, and characterization of a novel, oil-degrading bacterium, Pseudomonas aeruginosa T1

A novel, oil-degrading bacterium (strain T1) was isolated from a hot spring in Hokkaido, Japan. It efficiently degrades different types of fats and oils, including edible oil waste. When grown in a mineral salt medium containing 1% triacylglycerol (as salad oil), hydrolysis products were 1,3- and 1,2-diacylglycerols, monoacylglycerol, and free fatty acid. However, these products were almost completely consumed during cultivation at 30 degrees C for 5 days, indicating that extracellular lipase acts randomly at different sn-positions of acylglycerols and that strain T1 has a high capacity to utilize free fatty acids. Secreted lipase activity was induced by salad oil and oleic acid. This strain was a Gram-negative straight rod shaped, aerobic, with a polar flagellum, capable of growing in temperature ranges between 15 degrees C and 55 degrees C. The 16S rRNA gene sequence analysis and DNA-DNA hybridization revealed it as a new strain of Pseudomonas aeruginosa. The type strain was T1.

AEROSOLIZED TISSUE PLASMINOGEN INHIBITOR IMPROVES PULMONARY FUNCTION IN SHEEP WITH BURN AND SMOKE INHALATION

Acute respiratory distress syndrome is a major complication in patients with thermal injury. The obstruction of the airway by cast material, composed in part of fibrin, contributes to deterioration of pulmonary gas exchange. We tested the effect of aerosol administration of tissue plasminogen activator, which lyses fibrin clots, on acute lung injury in sheep that had undergone combined burn/smoke inhalation injury. Anesthetized sheep were given a 40% total body surface, third degree burn and were insufflated with cotton smoke. Tissue plasminogen activator (TPA) was nebulized every 4 h at 1 or 2 mg for each nebulization, beginning 4 h after injury. Injured but untreated control sheep developed multiple symptoms of acute respiratory distress syndrome: decreased pulmonary gas exchange, increased pulmonary edema, and extensive airway obstruction. These control animals also showed increased pulmonary transvascular fluid flux and increased airway pressures. These variables were all stable in sham animals. Nebulization of saline or 1 mg of TPA only slightly improved measures of pulmonary function. Treatment of injured sheep with 2 mg of TPA attenuated all the pulmonary abnormalities noted above. The results provide evidence that clearance of airway obstructive cast material is crucial in managing acute respiratory distress syndrome resulting from combined burn and smoke inhalation injury.

Acute effects of combined burn and smoke inhalation injury on carboxyhemoglobin formation, tissue oxygenation, and cardiac performance

The objective of this study was to determine the relationship between carboxyhemoglobin (COHb) formation, global oxygen transport, and cardiac performance in the acute phase of combined burn and smoke inhalation injury. Following a third degree burn of 20% of the total body surface area, adult sheep were subjected to cotton smoke (4x12 breaths) according to an established protocol. Compared with baseline (BL), the burn injury led to an immediate and sustained COHb-independent depression in myocardial contractility. Despite a progressive increase in COHb formation, up to a maximum of 78+/-3% (P < 0.001 vs BL), smoke inhalation did not further impair these hemodynamic changes. This study demonstrated that in the early stage of combined burn and smoke inhalation injury, the depression in cardiac function is basically triggered by the burn injury, whereas COHb generation secondary to cotton smoke exposure primarily contributes to pulmonary shunting.

Temperature and nutrient availability control growth rate and fatty acid composition of facultatively psychrophilic Cobetia marina strain L-2

A facultative psychrophilic bacterium, strain L-2, that grows at 0 and 5 degrees C as minimum growth temperatures in complex and defined media, respectively, was isolated. On the basis of taxonomic studies, strain L-2 was identified as Cobetia marina. The adaptability of strain L-2 to cold temperature was higher than that of the type strain and of other reported strains of the same species. When the bacterium was grown at 5-15 degrees C in a defined medium, it produced a high amount of trans-unsaturated fatty acids. By contrast, in a complex medium in the same temperature range it produced a low amount of trans-unsaturated fatty acids. In the complex medium at 5 degrees C, the bacterium exhibited a three-fold higher growth rate than that obtained in the defined medium. Following a temperature shift from 11 to 5 degrees C, strain L-2 grew better in complex than in defined medium. Furthermore, when the growth temperature was shifted from 0 to 5 degrees C both the growth rate and the yield of strain L-2 growing in complex medium was markedly enhanced. These phenomena suggest that an upshift of the growth temperature had a positive effect on metabolism. The effects of adding complex medium components to the defined medium on bacterial growth rate and fatty acid composition at 5 degrees C were also studied. The addition of yeast extract followed by peptone was effective in promoting rapid growth, while glutamate addition was less effective, resulting in a cis-unsaturated fatty acid ratio similar to that of cells grown in the complex medium. These results suggest that the rapid growth of strain L-2 at low temperatures requires a high content of various amino acids rather than the presence of a high ratio of cis-unsaturated fatty acids in the cell membrane.

Carboxyhemoglobin formation following smoke inhalation injury in sheep is interrelated with pulmonary shunt fraction

Carboxyhemoglobin (COHb) formation is triggered by the inducible isoform of heme oxygenase (HO-1) catalyzing carbon monoxide (CO) production through breakdown of heme molecules, exposure to CO or both. In the setting of CO poisoning, COHb is regarded as a reliable marker characterizing both severity of injury and efficacy of treatment strategies. This study was designed as a prospective laboratory experiment to elucidate potential interdependencies between COHb generation, oxygenation, and pulmonary shunt fraction (Qs/Qt) in an ovine model of smoke inhalation injury. Chronically instrumented ewes (n=15) were repeatedly subjected to cotton smoke (4 x 12 breaths) according to an established protocol. This approach resulted in a progressive increase in COHb formation that was interrelated with the degree of Qs/Qt (P<0.001) and inversely correlated with both arterial and mixed venous HbO(2) saturation (r=-0.96 and -0.93). Although the arteriovenous COHb gradient successively decreased over time, COHb determined in venous blood underestimated the arterial content.

Diagnosis of acute brain-stem infarcts using diffusion-weighed MRI

There are many reports on acute cerebral infarcts diagnosed by diffusion-weighted MRI (DWI), but few describe brain-stem infarcts diagnosed by this method. Using the apparent diffusion coefficient (ADC), we studied 18 consecutive patients with brain-stem infarcts who underwent DWI during the acute phase. We calculated and compared the ADC ratio (lesion ADC/contralateral ADC) in 10 patients with brain-stem and 23 with supratentorial cortical infarcts examined within 24 h of the onset of stroke. Ischaemic brain-stem lesions were detected in all 15 patients who underwent DWI more than 3 h after the onset, but not in two who had DWI within 3 h of the onset; their ADC ratio was more than 0.95. ADC ratios in patients with brain-stem infarcts decreased as the interval between onset and DWI increased; the decrease was slower than in patients with supratentorial cortical infarcts.

MFE1, a member of the peroxisomal hydroxyacyl coenzyme A dehydrogenase family, affects fatty acid metabolism necessary for morphogenesis in Dictyostelium spp

Beta-oxidation of long-chain fatty acids and branched-chain fatty acids is carried out in mammalian peroxisomes by a multifunctional enzyme (MFE) or D-bifunctional protein, with separate domains for hydroxyacyl coenzyme A (CoA) dehydrogenase, enoyl-CoA hydratase, and steroid carrier protein SCP2. We have found that Dictyostelium has a gene, mfeA, encoding MFE1 with homology to the hydroxyacyl-CoA dehydrogenase and SCP2 domains. A separate gene, mfeB, encodes MFE2 with homology to the enoyl-CoA hydratase domain. When grown on a diet of bacteria, Dictyostelium cells in which mfeA is disrupted accumulate excess cyclopropane fatty acids and are unable to develop beyond early aggregation. Axenically grown mutant cells, however, developed into normal fruiting bodies composed of spores and stalk cells. Comparative analysis of whole-cell lipid compositions revealed that bacterially grown mutant cells accumulated cyclopropane fatty acids that remained throughout the developmental stages. Such a persistent accumulation was not detected in wild-type cells or axenically grown mutant cells. Bacterial phosphatidylethanolamine that contains abundant cyclopropane fatty acids inhibited the development of even axenically grown mutant cells, while dipalmitoyl phosphatidylethanolamine did not. These results suggest that MFE1 protects the cells from the increase of the harmful xenobiotic fatty acids incorporated from their diets and optimizes cellular lipid composition for proper development. Hence, we propose that this enzyme plays an irreplaceable role in the survival strategy of Dictyostelium cells to form spores for their efficient dispersal in nature.

Novosphingobium tardaugens sp. nov., an oestradiol-degrading bacterium isolated from activated sludge of a sewage treatment plant in Tokyo

An oestradiol-degrading bacterium isolated at a sewage treatment plant in Tokyo was studied phenotypically, genotypically and phylogenetically. Analysis of its 16S rDNA sequence, DNA base composition, whole-cell fatty acid profile and isoprenoid quinone composition, as well as the presence of sphingoglycolipid, revealed that the isolate is a member of the genus Novosphingobium. However, the sequence similarity of its 16S rDNA to those of known Novosphingobium species was no higher than 97%, implying that the isolate is distinctive. The results of DNA-DNA hybridization experiments and physiological characterization also indicated that the isolate represents a novel Novosphingobium species, for which the name Novosphingobium tardaugens sp. nov. is proposed; strain ARI-1T (=JCM 11434T =ATCC BAA-531T =IFO 16725T) is the type strain.

A mass of flesh: schizophrenic Rorschach percepts

The present study reports the recent finding that schizophrenic patients produce Rorschach percepts implying a mass of flesh (flesh mass). Although typically directly referring to a mass of flesh or muscle, the flesh masses were seen more broadly, in modified forms such as animals or human beings with diminution of head, arms, or legs. From observations on 76 chronic schizophrenics, inclusion and exclusion criteria were developed to reliably detect both explicit and implicit flesh masses. The presence or absence of the flesh mass was further examined in the Rorschach data of 22 patients with acute schizophrenia, 30 with anxiety disorders, 16 with psychotic mood disorders, and 28 normal adults. Diagnoses were made according to DSM-IV. Flesh masses were seen in 75 of 76 cases of chronic schizophrenia, in all cases of acute schizophrenia, in two patients with anxiety disorders, and in one patient with a mood disorder. Normal adults did not perceive any flesh mass. Flesh masses proved to be characteristic of schizophrenia, whether chronic or acute.

A characteristic feature of acute haematomas in the brain on echo-planar diffusion-weighted imaging

Diffusion-weighted MRI (DWI) is used in the diagnosis of acute ischaemic disease of the brain, but it is not clear whether or not it can be used to differentiate an acute haematoma from an infarct. Our purpose was to identify any characteristic feature of acute haematomas which can be recognised on DWI and to evaluate the usefulness of DWI in acute cerebral stroke. We examined nine patients with acute haemorrhage using CT and MRI including DWI. We measured the volume and apparent diffusion coefficient (ADC) of the haematomas. All showed heterogeneous signal on DWI, and the centre of the large (>20 ml) haematomas especially a mixed pattern with high and low signal. The characteristic feature of acute haematomas was a peripheral low-signal region, found in all subjects regardless of the size of the haematoma; acute infarcts did not show this. This low-signal rim on DWI may be useful for differentiating an acute haematoma from an infarct.