Behavioral detection of acoustic particle motion by a teleost fish (Astronotus ocellatus): sensitivity and directionality

Behavioral detection thresholds for oscars (Astronotus ocellatus) were measured in response to linear, oscillatory motion at 100 Hz along seven axes (-90 degrees, -60 degrees, -30 degrees, 0 degree, +30 degrees, and +60 degrees in azimuth, where 0 degree is the fish longitudinal axis; and the vertical axis) using a cardiac classical conditioning paradigm. Thresholds at all selected axes ranged from -58 to -56 dB re: 1 micron, which corresponds to 1.2 to 1.6 nm displacement (RMS). Thus, oscars appear to be equally sensitive to stimulation at all axes in three dimensional space. Behavioral thresholds of the oscar are close to the neural thresholds obtained from the most sensitive auditory nerve fibers in two other species, the goldfish (Carassius auratus) and the toadfish (Opsanus tau).

Succession of mutations in the Sabin strain of type 3 poliovirus replicating in the central nervous system of monkeys

Sabin strains of oral poliovirus vaccine (OPV) undergo limited genetic changes during replication in cell cultures, the gastrointestinal tract of vaccinees, and the central nervous system of monkeys. Some of these changes are associated with loss of attenuation markers. Here we report the dynamics of mutant accumulation in the Sabin strain of poliovirus type 3 inoculated intraspinally into monkeys. Thr --> lle reversion in amino acid 6 of VP1 (2493 C --> U) occurred within the first few days postinoculation (p.i.), but decreased on later days and completely disappeared by Day 17 p.i. 472 U --> C reversion in the 5'-untranslated region appeared to accumulate slower and by Day 17 completely substituted for the vaccine-type nucleotide at this site. These results indicate that experimental infection of the central nervous system of monkeys consists of early and late phases in which a different genetic constitution of the virus is favored. In several isolates one additional neurovirulent revertant was found: a Phe --> Ser at amino acid 91 of VP3 (2034 U --> C). Since this mutation was never detected in vaccine lots and is strongly selected against in cell cultures at temperatures below 38.5 degrees, it does not threaten the safety of OPV.

Laboratory investigation of ecological factors influencing the environmental presence of Burkholderia pseudomallei

Factors like temperature, pH value, water content in soil, and ultraviolet rays that might have influence on the survival of environmental Burkholderia pseudomallei strains were evaluated. Data showed that the optimal temperature and pH value for B. pseudomallei were 24 C to 32 C and 5 to 8, respectively. Water content in soil of less than 10% brought about the death of the bacteria within 70 days, while water content of more than 40% maintained bacteria life for 726 days. The bacteria were easily killed by ultraviolet rays at 465 mu W/cm2 for 7.75 min while other permanent soil bacteria were killed at 1,860 mu W/cm2 for 31 min. From these results, it could be concluded that proper temperature, enough water in soil, and suitable soil pH might be the three major ecological conditions governing the environmental presence of B. pseudomallei.

Comparative study on the mechanism of formation of pulse manifestations in coronary heart disease and hematopathic patients

Most patients suffering from coronary heart disease have string--like pulse due mainly to disorder of cardiac function, lowered arterial compliance and increased total peripheral resistance. The common type of pulse in hematopathy patients is rapid, thready, string--like and slippery, due mainly to increased compensatory pumping action of heart, shortening of ejection time of left ventricle, relatively better vessel compliance and blood rheology as well as low total peripheral resistance.

Amino acid tandem repeats within a late viral gene define the central variable region of African swine fever virus

The central variable region (CVR) of the African swine fever virus (ASFV) genome is contained within the 9-RL open reading frame (ORF). ORF 9-RL of the ASFV isolate Malawi Lil-20/1 predicts a protein of 614 amino acids with amino- and carboxy-terminal hydrophobic regions and a centrally located hydrophilic region. The CVR of the genome, located centrally within this ORF, is 372 bp and contains a 132-bp direct repeat. The translated CVR within ORF 9-RL contains 31 tandem tetramers, predominantly NADT, NANT, NVDT, and, in a few cases, CAST, GAST, or CADT. In vitro translation of 9-RL yielded a 94-kDa protein that was strongly reactive with convalescent pig serum while monospecific 9-RL antiserum identified a late viral protein of 94 kDa in ASFV-infected macrophages. The protein, detected by immunofluorescence staining with 9-RL antiserum, was distributed homogeneously throughout the cytoplasm of infected Vero cells. 9-RL protein size varied among different viral isolates and among cell-culture-adapted viruses. Protein size increased proportionately with the degree of cell culture adaptation and was directly correlated with the size of the CVR present within the ORF (300-500 bp). Analysis of the number and composition of tandem tetramers present within the CVR of a given ASFV isolate may prove useful for identifying and/or grouping ASFV isolates.

[Study on pharmacological regulation of the peritoneal stomata and its computer image processing]

Pharmacological regulation of the peritoneal stomata was studied by using traditional Chinese medicine and a medical image processing system attached to SEM. The results showed that the numbers, diameters and distributive density of the peritoneal stomata were significantly increased (P < 0.05) in the groups of white atractylodes rhizome and the pilose asiabell root. However, the effect of astraglus root was not obvious in comparison with the controls (P > 0.05). This was for the first time to show the regulation of the peritoneal stomata by using traditional Chinese medicines. According to the mechanism of the peritoneal stomata and ascites drainage, white atractylodes rhizome and pilose asiabell root may exert an important action on ascites treatment.

Blink reflex: normal values and its findings on peripheral facial paralysis

OBJECTIVE

To establish the normal values of blink reflex (BR) in healthy subjects and investigate the manifestations of BR in patients with peripheral facial paralysis (PFP).

METHODS

BR was investigated in 23 patients with PFP and 50 healthy persons serving as control. While stimulating the supraorbital nerve on one side, the reflex responses of bilateral inferior-orbicularis oculi were recorded respectively, in which the two components recorded on the ipsilateral side of stimulation were named R1, R2 and the contralateral one, R2'.

RESULTS

There was no significant difference between sexes, sides and among various groups of age R1, R2 and R2'. The mean latency of R1 was 10 msec and R2, R2', 29 msec. The absolute values of the amplitude were of relatively smaller significance due to their great variance, whereas the amplitude ratio between two sides was of some value. All patients showed absent response, delayed latency or/and abnormal amplitude on the paretic side, regardless of the side of stimulation, indicating a typically efferent involvement.

CONCLUSION

BR is another objective and noninvasive test for facial paralysis in evaluating the lesion site, scope and the abnormality degree, and predicting the prognosis if combined with the clinical conditions.

Close correspondence between the action spectra for the blue light responses of the guard cell and coleoptile chloroplasts, and the spectra for blue light-dependent stomatal opening and coleoptile phototropism

Fluorescence spectroscopy was used to characterize blue light responses from chloroplasts of adaxial guard cells from Pima cotton (Gossypium barbadense) and coleoptile tips from corn (Zea mays). The chloroplast response to blue light was quantified by measurements of the blue light-induced enhancement of a red light-stimulated quenching of chlorophyll a fluorescence. In adaxial (upper) guard cells, low fluence rates of blue light applied under saturating fluence rates of red light enhanced the red light-stimulated fluorescence quenching by up to 50%. In contrast, added blue light did not alter the red light-stimulated quenching from abaxial (lower) guard cells. This response pattern paralleled the blue light sensitivity of stomatal opening in the two leaf surfaces. An action spectrum for the blue light-induced enhancement of the red light-stimulated quenching showed a major peak at 450 nm and two minor peaks at 420 and 470 nm. This spectrum matched closely an action spectrum for blue light-stimulated stomatal opening. Coleoptile chloroplasts also showed an enhancement by blue light of red light-stimulated quenching. The action spectrum of this response, showing a major peak at 450 nm, a minor peak at 470 nm, and a shoulder at 430 nm, closely matched an action spectrum for blue light-stimulated coleoptile phototropism. Both action spectra match the absorption spectrum of zeaxanthin, a chloroplastic carotenoid recently implicated in blue light photoreception of both guard cells and coleoptiles. The remarkable similarity between the action spectra for the blue light responses of guard cells and coleoptile chloroplasts and the spectra for blue light-stimulated stomatal opening and phototropism, coupled to the recently reported evidence on a role of zeaxanthin in blue light photoreception, indicates that the guard cell and coleoptile chloroplasts specialize in sensory transduction.

Histidine patch thioredoxins. Mutant forms of thioredoxin with metal chelating affinity that provide for convenient purifications of thioredoxin fusion proteins

A cluster of surface amino acid residues on Escherichia coli thioredoxin were systematically mutated in order to provide the molecule with an ability to chelate metal ions. The combined effect of two histidine mutants, E30H and Q62H, gave thioredoxin the capacity to bind to nickel ions immobilized on iminodiacetic acid- and nitrilotriacetic acid-Sepharose resins. Even though these two histidines were more than 30 residues apart in thioredoxin's primary sequence, they were found to satisfy the geometric constraints for metal ion coordination as a result of the thioredoxin tertiary fold. A third histidine mutation, S1H, provided additional metal ion chelation affinity, but the native histidine at position 6 of thioredoxin was found not to participate in binding. All of the histidine mutants exhibited decreased thermal stability as compared with wild-type thioredoxin; however, the introduction of an additional mutation, D26A, increased their melting temperatures beyond that of wild-type thioredoxin. The metal chelating abilities of these histidine mutants of thioredoxin were successfully utilized for convenient purifications of human interleukin-8 and -11 expressed in E. coli as soluble thioredoxin fusion proteins.

The effects of radiofrequency catheter ablation on the metabolic enzymes and Ca(++)-ATPase of myocytes

Using histochemical technique, the effects of radiofrequency catheter ablation (RFCA) on the activities of LDH, SDH, CCO, and Ca++-ATPase of guinea-pig ventricular myocytes were examined. The histological changes were observed for comparison. Radiofrequency energy (500 kHz) delivered was 20 W x 10 s. The results were as follows: RFCA resulted in significant impairments in all the four kinds of enzymes but without statistical differences in the areas involved in this energy level. No statistically significant difference was found between the ranges of enzymatic damages and areas of pathological lesions. These findings showed a consistency in areas of the histological and histochemical lesions resulted from RFCA.

[Curative effect of Interfon-Alpha in children with infectious mononucleosis]

Thirty-one cases of infectious mononucleosis treated with Interfon-Alpha were reported. The dose of intramuscular injection was one million units per day for 5-7 days. The recovery course of fever, angina, lymphadenopathy and hepatosplenomegaly was much shorter in the study group than in the control group (27 cases). The results suggested that interfon-Alpha should be efficacious against EBV activity and might shorten the course of this disease.

Stable partial debonding of the cement interfaces indicated by a finite element model of a total hip prosthesis

A simplified three-dimensional finite element model of the femoral component of a cemented total hip prosthesis was used to investigate whether partial debonding at the stem-cement or bone-cement interfaces propagates in a stable or unstable manner, and to assess the resultant variation of the stresses within the cement layer. The likelihood of unstable debonding under tensile failure mode was assessed both by a conventional monotonic strength criterion and by a fracture mechanics approach that took into account debonding due to fatigue loading. The model predicted that partial debonding at the cement interfaces would be stable and would not precipitate complete debonding. Among the various bonding conditions that were investigated, the maximum tensile stress within the cement layer was least with a small amount of debonding rather than with complete bonding. These results were consistent with clinical observations of nonprogressive or slowly progressive separation at cement interfaces in cemented femoral components that were otherwise well functioning and asymptomatic.

Limited genetic changes in the Sabin 1 strain of poliovirus occurring in the central nervous system of monkeys

Replication of attenuated poliovirus strains results in their partial deattenuation. Recently we identified mutations accumulating in the Sabin 1 poliovirus in cell cultures. Here we report genetic changes occurring in this virus during replication in the central nervous system (CNS) of monkeys. Viruses isolated from different parts of the CNS of rhesus monkeys (inoculated into the spinal cord) were screened for sequence heterogeneities and newly identified mutations were independently confirmed and quantified using mutant analysis by PCR and restriction enzyme cleavage (MAPREC). All consistently accumulating mutations identified in this study were located in untranslated regions: GU-->AU or GU-->GC substitution at a complementary pair formed by nucleotides 480 and 525, U-->C substitution at nucleotide 612, and GU-->AU or GU-->GC substitution of a base pair formed by the nucleotides 7427/7441 immediately preceding the poly(A) tract. All these mutations except one (7427) were previously identified in cell culture passages or stool isolates from vaccinees. Sequencing of 11 CNS isolates also identified a few random silent mutations that accumulated as neutral 'passengers', passively co-selected with genuinely selectable mutations present on the same RNA molecule. One isolate also contained the wild-type base at nucleotide 2741 (Ala88-->Thr in VP1). Our results demonstrate a remarkable genetic stability of the Sabin 1 poliovirus in the CNS of monkeys, suggesting that deattenuation is determined by a very limited number of mutations. These mutations can be assayed by MAPREC to monitor the consistency of oral poliovirus vaccine (OPV) production.

Analysis of 94 kb of the chlorella virus PBCV-1 330-kb genome: map positions 88 to 182

Analysis of 94 kb of DNA, located between map positions 88 and 182 kb in the 330-kb chlorella virus PBCV-1 genome, revealed 195 open reading frames (ORFs) 65 codons or longer. One hundred and five of the 195 ORFs were considered major ORFs. Twenty-six of the 105 major ORFs resembled genes in the databases including three chitinases, a chitosanase, three serine/threonine protein kinases, two additional protein kinases, a tyrosine protein phosphatase, two ankyrins, an ornithine decarboxylase, a copper/zinc-superoxide dismutase, a proliferating cell nuclear antigen, a DNA polymerase, a fibronectin-binding protein, the yeast Ski2 protein, an adenine DNA methyltransferase and its corresponding DNA site-specific endonuclease, and an amidase. The genes for the 105 major ORFs were evenly distributed along the genome and, except for one noncoding 1788-nucleotide stretch, the genes were close together. Unexpectedly, a 900-bp region in the 1788-bp noncoding sequence resembled a CpG island.

Target imaging diagnosis of human brain glioma. Clinical analysis of 40 cases

OBJECTIVE

To establish a method for localization and qualitative diagnosis of glioma.

METHODS

The monoclonal antibody SZ-39 against human glioma was labelled with 131I and injected intravenously into 40 patients with intracranial occupying lesions proved by X-CT. 72 hours after 131I-McAb-SZ39 administration, cranial bone nuclide-imaging agent 99mTc-MDP was injected intravenously, and the patients were examined by SPECT scan with dual nuclide double channel tomography and special software. On radio-immuno-image, the immunocomplex formed by specific conjugation of 131I-McAb-SZ39 with target tissue was red, while the cranial bone incorporated with 99mTc-MDP was green. The location of the immunocomplex area could be identified by the superimposition of the images.

RESULTS

21 patients with positive targeting diagnosis of glioma showed the accuracy rate checked by SPECT was 81%(17/21) and by X-CT 48% (10/21). Seven patients with negative targeting diagnosis showed the accuracy rate checked by SPECT was 86%(6/7) and by X-CT 14% (1/7). Pathologically, the sensitivity of targeting SPECT to glioma was 94.5%(17/18) and that of X-CT 55%(10/18).

CONCLUSIONS

Targeting SPECT examination could be used for localization and qualitative diagnosis of glioma and make up the inadequacy of X-CT in the qualitative diagnosis of atypical incipient and recurrent glioma, meningioma, metastatic carcinoma, and inflammatory lesions of brain.

Effect of processing on fumonisin content of corn

Fumonisins (FBs) are a family of mycotoxins produced by Fusarium moniliforme and F. proliferatum, predominant corn pathogens, and are found in most corn-containing foods. The FBs are heat stable, resistant to ammoniation, and unlike most mycotoxins, are water-soluble. The levels in corn and corn-containing foods will be presented ranging from < 20 ppb to > 2 ppm. Washing of contaminated FB-corn with water did not reduce the measured FB levels of significantly. The traditional processing step to make tortilla flour, nixtamalization [Ca(OH)2 cooking] to produce masa, reduced FB levels but produced hydrolyzed FB which was almost as toxic as FB. Retorting sweet corn in brine apparently produced hydrolyzed FB. Fermentation of corn to ethanol did not alter FB levels but distillation yielded FB-free ethanol. Attempts to enzymatically modify FB with several enzymes were unsuccessful. Reactions between FB and reducing sugars (glucose or fructose) to produce Schiff's bases yielded products that were not toxic. The effects of these processing treatments must be evaluated both chemically and biologically.

Geographical distribution of Pseudomonas pseudomallei in China

1,366 samples of soil and water from southern China coastal provinces were examined for Pseudomonas pseudomallei. Data showed that 58 samples were positive for this bacteria, which is primarily distributed in Hainan Province and the coastal region of mainland. This paper confirmed the environmental presence of P. pseudomallei in China and showed that the distribution of this pathogen has at least reached a latitude of 25.5 degrees north.

Harmful effects of MSG on function of hypothalamus-pituitary-target gland system

It has been demonstrated that neonatal administration of monosodium glutamate (MSG) results in a clearly defined lesion of the arcuate nucleus (AN) of the hypothalamus. The present study shows that fat was accumulated in the abdomen of male rats treated with MSG; weights of the body, pituitary and testis were lower; beta-EP content in hypothalamus decreased while L.EnK content increased; serum LH, FSH, TSH, GH and TS levels all decreased in varying degrees while serum PRL level significantly increased. The cAMP content lowered in pituitary, but nor in testes; clear histological changes occurred in testicular tissue; Se-GSH-Px activity in both testis and adrenal gland lowered while LPO level significantly increased. Both Se-GSH-Px activity and LPO level in liver increased. These results indicate that MSG is harmful to the function of the hypothalamus-pituitary-target system of neonatal rats.

Involvement of Ral GTPase in v-Src-induced phospholipase D activation

An early response to the tyrosine kinase activity of v-Src is an increase in phospholipase D (PLD) activity, which leads to the generation of biologically active lipid second messengers, including phosphatidic acid, lysophosphatidic acid and diacylglycerol. We have recently demonstrated that v-Src-induced PLD activity is mediated by Ras, although Ras involvement was indirect, requiring a cytosolic factor for PLD activation. Ras interacts with and activates Ral-GDS, the exchange factor responsible for the activation of Ral GTPases. Here we report that this newly identified Ras/Ral signalling pathway mediates PLD activation by v-Src. PLD activity could be precipitated from v-Src-transformed cell lysates with immobilized RalA protein and with an anti-Ral antibody. A mutation to the region of RalA analogous to the 'effector domain' of Ras did not reduce the ability of RalA to complex with PLD, although deletion of a Ral-specific amino-terminal region did. Overexpression of RalA potentiated PLD activation by v-Src, and expression of dominant negative RalA mutants inhibited both v-Src- and v-Ras-induced PLD activity. Thus RalA is involved in the tyrosine kinase activation of PLD through its unique N terminus, and that PLD is a downstream target of a Ras/Ral GTPase cascade.

Population characteristics of hepatic dihydropyrimidine dehydrogenase activity, a key metabolic enzyme in 5-fluorouracil chemotherapy

Dihydropyrimidine dehydrogenase is the initial rate-limiting enzyme in catabolism of 5-fluorouracil, one of the most widely used cancer chemotherapeutic agents. Previous studies have shown the clinical importance of determination of dihydropyrimidine dehydrogenase in patients with cancer, particularly in those with deficiency of this enzyme who experience severe 5-fluorouracil-associated toxicity (including death) after 5-fluorouracil treatment. In the present study, dihydropyrimidine dehydrogenase activity was determined in 138 donor liver samples. A normal distribution of human liver dihydropyrimidine dehydrogenase activity was shown. The mean enzyme activity was compared across different groups by age, gender, and race, with no significant differences observed except that the mean enzyme activity in women was slightly higher than that observed in men. With use of a polyclonal antibody generated against human liver dihydropyrimidine dehydrogenase, Western blot analysis showed that dihydropyrimidine dehydrogenase protein in the liver cytosol correlated with the activity of this enzyme.