Determination of the fast axis with an infrared spectrometer for quartz and mica waveplates

The variation of dichroism with wavelength is used in an infrared spectrometer to find the fast and slow axes of quartz and mica waveplates.

Effects of cycloheximide on abscisic Acid biosynthesis and stomatal aperture in bean leaves

Cycloheximide was shown to block abscisic acid (ABA) biosynthesis in nonstressed as well as in stressed Phaseolus vulgaris leaves. Leaf wilting caused by cycloheximide resulted from increased stomatal opening as judged by a decreased stomatal diffusion resistance. The inhibition of ABA biosynthesis by cycloheximide was at least partially responsible for the increase in stomatal opening as suggested by the cooccurrence of inhibition of ABA biosynthesis and increased stomatal opening, and the partial reversal of stomatal opening in cycloheximide-treated leaves by exogenous ABA. Dark treatment failed to close stomatal in cycloheximide-treated leaves, suggesting that stomatal closure in response to darkness may normally be mediated by ABA.

Evaluation of mutagenicity of restorative dental materials using the Ames Salmonella/microsome test

Compounds of five commercially available dental material kits were examined for mutagenic potential by use of the Ames Salmonella/microsome test. Dimethyl sulfoxide (DMSO) was used as the solvent for all materials, except MONO-LOK2 Primer and Right-On Activator, which were dissolved in 95% ethanol. The Tenure, Fuji, and Gluma materials were initially screened at 2 mg (solids) or 2 microL (liquids) per plate, without S9 (Aroclor 1254-induced rat liver microsomes), and dose-response studies were conducted for those materials showing potential mutagenicity. The components of three dental kits, MONO-LOK2, Right-On, and Gluma, were further examined, both with and without S9 activation, at doses of 0.2, 4, 20, 100, 500, and 2500 micrograms (nL for liquid components) per plate. The data showed no mutagenic potential for the components of Fuji Glass Ionomer (Type III), Tenure Dentin Bonding System, and MONO-LOK2 kits, or Right-On Paste. However, Gluma 3, a component of the Gluma/Lumifor Bonding System, exhibited mutagenic activity in a dose-response manner. The mutagenicity of Gluma 3 was demonstrated in repeated experiments. Gluma 4 and the resin of the Gluma dental kit, as well as Right-On Activator, caused a slight increase in the number of revertants, and judgment regarding their mutagenicity could not be made conclusively. The results of this study indicate that some commercial dental materials may not have been adequately tested for mutagenicity, and that a reliable test program for evaluation of mutagenicity of dental materials is needed so that their safe use in dental practice can be ensured.

The repair of nail deformities with the nonvascularized nail bed graft: indications and results

Twenty-four cases of nonvascularized nail bed grafting to correct nail deformities were reviewed. The highest success rate in improving the appearance of the deformed nail, 86%, was achieved when the split-thickness nail bed graft of sterile matrix was used to correct a nail deformity caused by a sterile matrix injury; the same procedure used to correct a nail deformity caused by a germinal matrix injury had a 0% success rate. Donor site morbidity occurred in 25% of split-thickness nail bed grafts and 100% of full-thickness nail bed grafts. The split-thickness nail bed graft of sterile matrix, if used in properly selected patients, will consistently improve the appearance of the deformed nail.

[Anti-inflammatory effect of aconitines]

Aconitines are the total alkaloids isolated from the main root of Aconitum carmichaeli. They have marked suppressive effect on the swelling of rat's hind paw induced by injections of fresh egg protein, carrageenin, histamine and 5-HT, on the mouse's ear oedema induced by bimethylphenyl, on the exudate and proliferation of granulation tissue of granuloma pouch induced by croton oil, on the leukocyte migration and on the contents of PGE in the exudate of the swelling hind paw induced by injecting carrageenin. Aconitines have been found useful in inhibiting significantly such immune inflammations as reversible passive Arthus reaction, rat's delayed skin hypersensitivity and adjuvant arthritis. They have also a noticeable analgesic effect.

[Establishment of hybridoma cell lines producing monoclonal antibodies against-p30 antigen]

BALB/c mice were immunized with the purified p30 antigen. SP2/0 myeloma cells and immune spleen cells were fused with 50% PEG (Sigma, MW 3,350-4,000). The cell fusion rate was 93.95%, and the antibody producing rate 21.01%. The technique of limiting dilution was used for cloning of the hybridoma cells. Two hybridoma cell lines E8 and G1 secreting McAb against p30 antigen were obtained. The number of chromosome of both E8 and G1 cell lines was 98.7 +/- 6.54 and 97.7 +/- 7.77, respectively. Results of the PAGE of the ascites generated by the hybridoma cell lines E8 and G1 showed a thick protein band at the gamma-region which was absent from the ascites generated by the SP 2/0 myeloma cells. The immunoglobulin of the McAb E8 and G1 belonged to IgG2 subclass. The results of the immunohistochemical method using the horseradish peroxidase conjugated antibody showed that both E8 and G1 McAb only reacted with epithelial cells of the normal human prostatic glands and their ducts, but did not cross-react with other thirty-four different kinds of normal human tissues. The results of inhibiting ELISA test showed that both E8 and G1 McAb were only inhibited by the human seminal plasma and p30, weakly inhibited by the adult male's urine, but were not inhibited by other eight different kinds of human body fluids and secretions as well as semen from eight different species of animals. It was concluded that McAb of E8 and G1 were organ and species specific.(ABSTRACT TRUNCATED AT 250 WORDS)

[Influence of iron deficiency anemia on development of thymus and spleen and adenosine deaminase activity in rats]

Models of rats with iron deficiency anemia (IDA) were established, and changes in development of the thymus and spleen and adenosine deaminase (ADA) activity in them studied. The size and weight of the thymus in IDA rats were decreased, which suggested that the development of the thymus was lowered; but the size and weight of the spleen in IDA group were increased. ADA activities of the thymus and the spleen in IDA rats were significantly decreased by 32.98% and 25.89%, respectively. One week after iron supplement, the weight of the thymus and spleen in IDS group returned to normal level (P greater than 0.05), and their ADA activity also significantly increased, but ADA activity of the thymus tissue did not return to the normal. The results suggested that the changes in ADA activity of the thymus and spleen tissues were related to iron deficiency. Stepwise regression analysis suggested that there was a negative correlation between ADA activity of the thymus tissue and FEP/Hb ratio.

Violaxanthin is an abscisic Acid precursor in water-stressed dark-grown bean leaves

The leaves of dark-grown bean (Phaseolus vulgaris L.) seedlings accumulate considerably lower quantities of xanthophylls and carotenes than do leaves of light-grown seedlings, but they synthesize at least comparable amounts of abscisic acid (ABA) and its metabolites when water stressed. We observed a 1:1 relationship on a molar basis between the reduction in levels of violaxanthin, 9'-cis-neoxanthin, and 9-cis-violaxanthin and the accumulation of ABA, phaseic acid, and dihydrophaseic acid, when leaves from dark-grown plants were stressed for 7 hours. Early in the stress period, reductions in xanthophylls were greater than the accumulation of ABA and its metabolites, suggesting the accumulation of an intermediate which was subsequently converted to ABA. Leaves which were detached, but not stressed, did not accumulate ABA nor were their xanthophyll levels reduced. Leaves from plants that had been sprayed with cycloheximide did not accumulate ABA when stressed, nor were their xanthophyll levels reduced significantly. Incubation of dark-grown stressed leaves in an (18)O(2)-containing atmosphere resulted in the synthesis of ABA with levels of (18)O in the carboxyl group that were virtually identical to those observed in light-grown leaves. The results of these experiments indicate that violaxanthin is an ABA precursor in stressed dark-grown leaves, and they are used to suggest several possible pathways from violaxanthin to ABA.

[Study on the fluorimetric determination of aluminum with H2QS and CTMAB in water]

A study on the fluorimetric reaction of Al-H2QS-CTMAB and conditions of the determination of aluminium in water by model 930 fluorimeter is reported. A good linear relationship between the strength of fluorescence and aluminum concentrations, ranging from 0 to 1.5 micrograms/10ml, is observed. Interferences from other constituents in water can be eliminated by the masking effect of 1, 10-phenanthroline and hydroxylamine hydrochloride and by using standard addition method. The coefficient of variation and recovery vary from 2.9% to 8.9% and from 87% to 105%, respectively. The detection limit is 3 x 10(-2) micrograms/ml. This method is rapid, sensitive, accurate and suitable for the determination of contents of aluminum in drinking and natural waters.

Design of bar code systems for accurate alignment: a new method

A method is proposed on the basis of a choice of the appropriate solution of simultaneous equations obtained in the course of linearization of the autocorrelation equation of a bar code system that is used for the purpose of accurate alignment. Numerical examples are presented to show the usefulness of this new method.

Fractal analysis of protein chain conformation

This paper presents a simple practical method for characterizing conformation of protein chains. A single number Df, as the fractal dimension, is assigned to each chain. Df = Ln(N)/Ln(N.d/L), where N is the number of the amino acid residues in the chain, L and d are the total length and the planar diameter of the chain, respectively. In general, 1 less than Df less than or equal to 2, which is related to the shape of the protein chain. These values are different from those of Stapleton's group, but in agreement with computer simulations.

Airborne concentrations and particle size distribution of allergen derived from domestic cats (Felis domesticus). Measurements using cascade impactor, liquid impinger, and a two-site monoclonal antibody assay for Fel d I

The recent development of a sensitive two-site monoclonal antibody immunoassay for the major cat allergen (Fel d I) has made it possible to make accurate measurements of airborne cat allergen using low volume samplers that do not disturb the room. Houses with cats had from 2 to 20 ng Fel d I/m3 air compared with less than 0.2 ng/m3 in houses without cats. Using a cascade impactor and a multistage liquid impinger, the particle size distribution of airborne Fel d I in nine houses was 75% on particle greater than or equal to 5 microns in diameter and 25% (range, 10 to 62%) on particles less than or equal to 2.5 microns. In a cat vivarium with 12 cats, the air contained 40 ng Fel d I/m3, but less than 2% was detected on particles less than or equal to 2.5 microns. The air exchange rate in the vivarium (approximately 15 changes/h) appears to be the major difference from domestic houses (less than 0.5 changes/h). Repeated studies in one house confirmed a very high proportion (approximately 60%) of Fel d I on small particles. During domestic cleaning, the levels of small particle allergen in this house approached those produced by a nebulizer for bronchial provocation, i.e., 40 ng/m3. These results show unequivocally that significant airborne Fel d I is associated with small particles, which remain airborne for long periods. These findings are strikingly different from previous results obtained with airborne dust mite allergen. The results provide an explanation for the distinctive rapid onset of asthma or rhinitis in patients allergic to cats and a basis for designing a policy to reduce airborne allergen in houses with cats.

Spontaneous mutations leading to antigenic variations in the glycoproteins of vesicular stomatitis virus field isolates

Strains of vesicular stomatitis virus, New Jersey serotype (VSV-NJ), isolated from diseased cattle or swine were examined by genomic RNA sequencing for genetic diversity potentially leading to antigenic variations in their type-specific glycoproteins as determined by reactivity with epitope-specific monoclonal antibodies (MAbs). Seven field isolates recovered in Colorado, New Mexico, Georgia, and Mexico during the widespread 1982-1985 epizootic in the western United States resembled the prototypic 1952 Hazelhurst subtype by partial sequence homology, but amino acid reversions to the 1949 Ogden subtype occurred frequently. When studies were performed with MAbs directed to the Ogden subtype glycoprotein, relatively limited antigenic variation, and only in neutralization epitope VIII, was noted among two of five epizootic isolates from Colorado and New Mexico. However, amino acid differences in the glycoprotein of a 1983 isolate from an enzootic region of Georgia resulted in major antigenic deficiencies in epitopes V, VI, and VII as determined by Western blotting and neutralization of infectivity with epitope-specific MAbs. Quite a few genetic but no antigenic differences were noted in an enzootic 1984 isolate from Mexico, a potential origin of the United States epizootic. Marked or complete loss of epitopes VII, VI, VIII, and V can be traced to spontaneous mutations leading to amino acid substitutions at glycoprotein positions 199, 263, 275, and 317, respectively, in the enzootic Georgia isolate 07/83-GA-P and the epizootic New Mexico isolate 06/85-NM-B. By comparison, closely adjacent amino acid substitutions at glycoprotein positions 210, 268, 277, and 364 occurred in epitope-deficient mutants selected for resistance to neutralization by MAbs specific for epitopes VII, VI, VIII, and V, respectively. Two neutralization epitopes designated X and XI were found to be unique for the G protein of the 1952 Hazelhurst isolate..../52-GA-P. The epitope X-specific MAb H21, in particular, failed to neutralize the infectivity not only of the Ogden subtype..../49-UT-B but also was ineffective against all the 1982-1985 field isolates. The classical 1952 Hazelhurst strain of VSV-NJ is genetically and antigenically quite different from those viruses isolated during the 1982-1985 epizootic.

Allelic variations in the human T cell receptor V beta 6.7 gene products

Polymorphisms of human TCR gene products have been suggested by the description of a mAb, OT145, that identifies a subset of TCRs in some individuals but not in others (6). Here we demonstrate that this mAb detects a TCR allotype of the V beta 6.7 gene. Two allelic products of this V gene differ by two nonconservative amino acid substitutions. The mAb OT145 appears to react with V beta 6.7 a gene products ("+" allele), but not with V beta 6.7b gene products ("-" allele). This represents the first direct demonstration that TCR V gene allotypes exist and provides a possible explanation for immune responses under the control of TCR V genes and for disease associations with TCR V genes.

Accurate reconstruction of three complementary laminar afferents to the adult hippocampus by embryonic neural grafts

The hippocampus receives a complex pattern of afferent nerve fibres, segregated in such a way that the different types of afferent axons terminate in strictly demarcated, contiguous, but non-overlapping territories at different proximo-distal levels on the dendrites. In this paper we have used a mouse allelic marking system to show that the dentate, hippocampal, and entorhinal afferents can all be restored correctly and specifically to their proper terminal territories by axonal projections formed by embryonic transplants placed in direct contact with the appropriate denervated terminal territories in adult host brains, and that incorrect connections are not formed. We conclude that the signals for correct reinnervation are present (or inducible by deafferentation) in the adult hippocampus. The embryo-to-adult transplantation experiments show that neither the temporal nor the spatial aspects of cell-to-cell confrontation which occur in normal development are necessary for the formation of specific laminar patterns of reinnervation in the adult.

Acute cerebral hemorrhage changes the nocturnal surge of plasma melatonin in humans

The diurnal rhythm of plasma melatonin was studied in 46 Chinese patients with acute cerebral hemorrhage. The state of consciousness of each patient was assessed clinically. The individual sites of lesion were determined by computerized tomography scanning. One to five days after stroke, blood samples were collected by venipuncture at 1000 and 1400 h in the daytime and 0200 and 0400 h at night. Plasma melatonin was extracted by dichloromethane and determined by radioimmunoassay. It was found that patients with lesions in the brain stem or in the third and lateral ventricles had melatonin levels significantly different from the other subjects in that these values were lower and lacking a nocturnal rise. These results are consistent with the presumptive retina-pineal pathway proposed in humans. Dramatic blunting or obliteration of the nocturnal melatonin surge in the blood was also observed in some patients with lesions in the frontal lobe, fronto-parietal lobe, parieto-temporal lobe, and basal ganglia. These brain regions are not involved in the retina-pineal pathway described in rodents or humans. Thus, our results suggest that brain regions other than the presumptive retina-pineal neural pathway may play an important role in the generation and/or regulation of the diurnal production and/or secretion of pineal melatonin in humans. However, a global functional disturbance caused by cerebral hemorrhage cannot be ruled out in some cases. It should be noted that many of the lesions leading to a change in the nocturnal rise of plasma melatonin were unilateral lesions. The significance of this finding is presently unknown. In addition, patients without a nocturnal rise of plasma melatonin were mostly comatose. They had lesions in the basal ganglion, fronto-parietal lobe, brain stem, and lateral and third ventricles. The latter findings suggest that in the brain, certain regions responsible for the state of consciousness of the individual may also be important to the dirunal rhythm of pineal melatonin secretion.

Detection of DNA adducts in skin biopsies of coal tar-treated psoriasis patients: immunofluorescence and 32P postlabeling

A clinical therapy for psoriasis, a hyperproliferative disease of the skin, utilizes topical application of crude coal tar sometimes followed by UV irradiation (Goeckerman therapy). To investigate the formation of covalent DNA adducts resulting from this therapy, skin biopsies were obtained from treated patients and controls. Indirect immunofluorescence staining with antisera generated against benzo(a)pyrene diol epoxide-modified DNA was used to investigate cell-specific localization of adduct formation. Specific nuclear staining was detected in the epidermal cells of all biopsies from treated patients but not from control biopsies obtained from untreated individuals. 32P postlabeling of DNA isolated from the biopsies was used to determine the spectrum of hydrophobic adducts present. A pattern of multiple adducts was detected in the samples obtained from the treated patients but not from controls.

[An experimental epidemiologic study of 4 different IUDs]

In dafeng county of Jiangsu province, 710 healthy women, aged 22-32 years, were randomly allocated to use one of the title IUDs 3-9 months postpartum in a single-blind manner. UCD is an inert stainless steel device assuming the shape of the uterine cavity, i.e., isosceles triangular-shaped. The study was designed to be completed in 2 years, and presently, 2 year data were presented. Results show that there were significant differences in the crude and cumulative termination rates of the 4 groups as analyzed by the logrank test. Besides, the crude termination rater of SSR was significantly higher than those of the other 3 IUDs (P less than 0.01). The main reasons for discontinuation of SSR were pregnancy and expulsion. In regard to the removal due to bleeding and pain, MLCu250 seemed to be the best, followed by UCD, and TCu 220C was the worst.

[Studies on oncogene and its products of human nasopharyngeal carcinoma]

Oncogene of nasopharyngeal carcinoma (NPC) by means of external origin DNA transfection experiment and its gene products by immunohistochemical method have been studied. These DNAs were isolated from human primary poorly differentiated NPC tissues and were transfected into NIH/3T3 mouse fibroblasts to induce the foci of the morphologically transformed cells in the culture, while DNAs of normal placenta tissues failed to do so. The DNAs were extracted from the primary and secondary transformed cells to analyse human sequence with human Alu sequence probe. The human sequence has been detected in the DNAs of the primary and secondary transformed foci cells, while none of the human sequence was detected in the DNAs of the control. The results indicated that human transforming sequences had been integrated into transformed cells. The malignant properties of the transformed foci cells were evidenced by tumorigenic experiment of nude mice. The transformed foci cells were inoculated subcutaneously in the nude mice and induced fibrosarcoma in vivo. The tumorigenic rate was 87.5%. It was further demonstrated that DNAs from human NPC possessed carcinogenicity and induced malignant transformation. The primary result revealed that the transforming gene of NPC may be homologue to Ha-ras oncogene. The expression of Ha-ras gene products-p21 has been studied in human NPC tissues. The primary results showed a positive expression of p21 in human NPC tissues by immunohistochemical method. The positive rate was 90.4%.

Liquid crystal TV-based white light optical tracking novelty filter

A compact white light optical tracking novelty filter is demonstrated. Based on the use of two inexpensive liquid crystal televisions, a filtered and collimated white light source, digital delay, and video recorder, this portable white light device performs two major image comparison operations, a real time image subtraction and novelty tracking operations. Some preliminary experimental results are presented.

Content-addressable-memory-based single-stage optical modified-signed-digit arithmetic

Using a novel nonholographic optoelectronic content-addressable memory in a free-space angular multiplexing geometry, a single-optical-stage compact parallel optical modified-signed-digit arithmetic processing architecture is proposed. Some spatial light modulator based experimental results are also presented.

Significance of premature stop codons in env of simian immunodeficiency virus

The location of the translational termination codon for the transmembrane protein (TMP) varies in three infectious molecular clones of simian immunodeficiency virus from macaques (SIVmac). The SIVmac251 and SIVmac142 infectious clones have premature stop signals that differ in location by one codon; transfection of these DNAs into human HUT-78 cells yielded virus with a truncated TMP (28 to 30 kilodaltons [kDa]). The SIVmac239 infectious clone does not have a premature stop codon in its TMP-coding region. Transfection of HUT-78 cells with this clone initially yielded virus with a full-length TMP (41 kDa). At 20 to 30 days posttransfection, SIVmac239 virus with a 41-kDa TMP gradually disappeared coincident with the emergence of a virus with a 28-kDa TMP. Virus production dramatically increased in parallel with the emergence of a virus with a 28-kDa TMP. Sequence analysis of viral DNAs from these cultures showed that premature stop codons arising by point mutation were responsible for the change in size of the TMP with time. A similar selective pressure for truncated forms of TMP was observed when the SIVmac239 clone was transfected into human peripheral blood lymphocytes (PBL). In contrast, no such selective pressure was observed in macaque PBL. When the SIVmac239 clone was transfected into macaque PBL and the resultant virus was serially passaged in macaque PBL, the virus replicated very well and maintained a 41-kDa TMP for 80 days in culture. Macaque monkeys were infected with SIVmac239 having a 28-kDa TMP; virus subsequently recovered from T4-enriched lymphocytes of peripheral blood showed only the 41-kDa form of TMP. These results indicate that the natural form of TMP in SIVmac is the full-length 41-kDa TMP, just as in human immunodeficiency virus type 1. Viruses with truncated forms of TMP appear to result from mutation and selection during propagation in unnatural human cells.

Genotoxic evaluation of chronic fluoride exposure: micronucleus and sperm morphology studies

The purpose of this study was to investigate the genotoxic effects of chronic fluoride exposure on mammalian cells in vivo by use of the mouse bone-marrow micronucleus test and the sperm morphology methodology. Mice of genotype B6C3F1 were obtained at weaning and maintained on a low-fluoride diet (less than 0.2 ppm F) ad libitum throughout the experiment. The animals were randomly assigned to seven groups and given fluoride (as sodium fluoride) in concentrations ranging from 1.0 to 75 ppm in the drinking water. Negative (distilled water) and positive (cyclophosphamide) controls were included. After a 21-week treatment period, the animals were killed by cervical dislocation, and blood was obtained by cardiac puncture. Slides of femur marrow cells were prepared and blindly examined for the frequency of micronucleated polychromatic erythrocytes (MN-PCE). Slides of sperm from the cauda epididymides of the male mice were also prepared and similarly examined for morphological abnormalities. Weight of the testes was recorded, and the plasma, humeri, testes, and carcasses were saved for fluoride analyses. Analyses of bone and plasma fluoride confirmed the effective absorption of fluoride following ingestion. The frequency of MN-PCE, the count of abnormal sperm, and the weight of the testes for mice chronically exposed to fluoride, in doses ranging from approximately 0.3 to 23 mg/kg/day, were not significantly different from those of the negative control animals. The results of this study support the view that fluoride has no genotoxic effects.

[Monoclonal antibodies specific for K88ab, K88ac and K88ad antigens of Escherichia coli]

A panel of twelve hybridoma cell lines, secreting specific antibodies to K88 adhesin antigens of enterotoxigenic Escherichia coli (ETEC) were established from eight separate fusions between mouse myeloma cell line Sp 2/0-Ag-14 and spleen cells from mice immunized with purified K88 antigens. Among the 12 monoclonal antibodies (MCA), K-A, K-35, K-11, and K-15 were K88a specific and reacted with all K88 adhesin bearing Escherichia coli strains tested, whatever K88ab, K88ac or K88ad they might be, as shown either in enzyme-linked immunosorbent assay (ELISA) or in direct agglutination test, whereas K32, K-4, and K-3 were specific for G88ab, K88ac, and K88ad respectively. The antigen patterns of 33 K88 bearing Escherichia coli strains covering 3 serotypes of K88ab, K88ac, and K88ad were analyzed by the use of these MCAs. The preliminary results showed that all Escherichia strains with the same serotype of K88 antigen shared at least one common type-specific antigenic determinant, that K88ad and K88ac strains enjoyed one common antigenic determinant that did not exist on K88ab strains, and that there were a few K88 antigenic determinants that appeared only on limited Escherichia coli strains of the same K88 serotype.

Optical parallel register transfer microoperations using holographic symbolic substitutions

Optical register transfer microoperations are proposed. Based on an optical holographic associative symbolic substitution, a hybrid optical word-parallel bit-serial register transfer processor architecture is described. Preliminary experimental results are included.

Compact parallel real-time programmable optical morphological image processor

Based on the parallel-processing and interconnection capabilities of optics, a novel, compact, real-time programmable parallel optical morphological filter is proposed and demonstrated. Using a real-time polarization-encoded image-casting scheme, some proof-of-principle experimental results are presented.

All-Carbon Molecules: Evidence for the Generation of Cyclo[18]carbon from a Stable Organic Precursor

The unambiguous structural characterization of a single-sized all-carbon molecule requires its chemical synthesis. For cyclo[18]carbon, ab initio calculations predict a relatively stable, cyclic D9h ground state geometry with alternating C-C (1.36 angstroms) and C identical withC (1.20 angstroms) bonds. The synthesis and x-ray crystal structure of a direct precursor to C(18) are described. The analysis of laser flash heating experiments on this precursor by time-of-flight mass spectroscopy shows a sequence of retro-Diels-Alder reactions leading to C(18) as the predominant fragmentation pattern. Structural evidence is provided for the generation of an all-carbon molecule from a well-characterized organic precursor.

Correlation of selenium, glutathione peroxidase activity and lipoperoxidation rates in dilated cardiomyopathy

The correlations of selenium level and glutathione peroxidase activity in blood and lipid peroxide concentration in plasma from 24 patients of dilated cardiomyopathy were studied. The results showed that in case of dilated cardiomyopathy, the selenium level and glutathione peroxidase activity were significantly lower (P less than 0.05), while lipid peroxide concentration was significantly higher (P less than 0.01) than those of healthy controls. Therefore, it is highly possible that dilated cardiomyopathy is associated with lipoperoxidation damage caused by the deficiency of both selenium and antioxidation ability.

The mouse thymidylate synthase promoter: essential elements are in close proximity to the transcriptional initiation sites

The promoter region of the mouse thymidylate synthase gene was analyzed by deletion and site-directed mutagenesis. Elimination of an upstream Sp1 element reduced expression threefold, whereas elimination of an adenovirus upstream stimulatory factor element had little effect. All of the upstream elements that are essential for promoter activity are located within 22 nucleotides of the first transcriptional initiation site.

[Study on molecular hybridization with biotin-labelled HPV 16 DNA probe in human cervical carcinoma]

Biotin-labelled human papillomavirus (HPV) 16 type DNA probe was prepared by the techniques of molecular biology. And dot hybridization technique was used to detect the HPV 16 homologous sequences in the tissues DNA of human cervical carcinoma. The results indicated that 16 cases out of 28 of the human cervical carcinoma tissues were positive. The positive rate was 57%. The other 4 cases of normal uterine cervix tissues were negative. Only 1 in 4 chronic cervicitis tissues showed positive. The HPV 16 plasmid DNA, as the positive control group, showed strong positive, while lambda-phage DNA was negative. The results have shown that the genome of the HPV actually exists in the tissue of the cervical carcinoma and that there is a close relationship between the cervical carcinoma and HPV infection. This experiment adopted the Biotin-labelled HPV 16 DNA probe. And it may provide us with a quick and sensitive method for investigation of the infection of HPV and its role in the carcinogenesis of cervical carcinoma.

Implementation of a binary optical full adder using a Venn diagram and optical phase conjugation

Conventional optical pattern logic schemes can only process two input variables at a time. We propose a new optical spatial encoding scheme that is capable of simultaneously processing multiple input variables. Based on this new scheme an optical full adder was experimentally demonstrated using a picosecond optical phase-conjugation device.

[Clinical analysis of 47 cases of epilepsy]

This article makes a clinical analyses of the general data concerning 47 epileptic cases in our hospital, and especially reports on the forensic psychiatric assessment of two out of the seven criminal cases, their history of illness and responsibility. In the assessment of such cases, special emphasis should be laid on the diagnosis of the epilepsy so as to avoid misdiagnosis. The author suggests that the patient folds no responsibility for his criminal behaviour during the attack. But he should be responsible in a diminished criminal for his criminal behavior when he is only suffering from a personality disorder, since he has some discriminative and self-control ability.

An analog of lophotoxin reacts covalently with Tyr190 in the alpha-subunit of the nicotinic acetylcholine receptor

Lophotoxin and lophotoxin analog-1 are natural diterpenes from coral that inhibit nicotinic acetylcholine receptors by covalent reaction with the acetylcholine recognition sites on the alpha-subunits. Although both toxins contain potentially reactive epoxides and alpha,beta-unsaturated aldehydes, the mechanism of their covalent reaction with the receptor is not known. The role of the alpha,beta-unsaturated aldehyde in analog-1 was investigated by reduction of the aldehyde to an alcohol with [3H]NaBH4. The reduced [3H]analog-1 bound selectively and covalently to the alpha-subunit of the receptor. Covalent binding was inhibited by agonists and antagonists, but not by noncompetitive allosteric inhibitors. The apparent dissociation constant of the reduced [3H]analog-1 was approximately 1.5 x 10(-6) M. These results demonstrate that the alpha,beta-unsaturated aldehyde in analog-1 is not an absolute requirement for covalent reaction with the receptor. Receptors were treated with the reduced-[3H]analog-1, and the labeled alpha-subunits were isolated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and digested with staphylococcal V8 protease. A labeled 20-kDa V8 protease fragment was purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and reverse-phase high performance liquid chromatography and subjected to sequence analysis. A peptide beginning at Ser173 was identified, and the label appeared in the 18th step corresponding to Tyr190. This assignment was confirmed by digestion of the labeled 20-kDa V8 protease fragment with cyanogen bromide, followed by purification of the labeled cyanogen bromide peptide on reverse-phase high performance liquid chromatography. A peptide beginning at Lys179 was identified, and the label appeared in the 12th step, again corresponding to Tyr190. Tyr190 may react with the coral toxin by nucleophilic addition at one of the carbons associated with an epoxide, and may form part of the alkylammonium-binding subsite of the acetylcholine recognition site.

Protein-RNA interactions in an icosahedral virus at 3.0 A resolution

Nearly 20 percent of the packaged RNA in bean-pod mottle virus (BPMV) binds to the capsid interior in a symmetric fashion and is clearly visible in the electron density map. The RNA displaying icosahedral symmetry is single-stranded with well-defined polarity and stereochemical properties. Interactions with protein are dominated by nonbonding forces with few specific contacts. The tertiary and quaternary structures of the BPMV capsid proteins are similar to those observed in animal picornaviruses, supporting the close relation between plant comoviruses and animal picornaviruses established by previous biological studies.

Macrophage activation by interferon-gamma from host-protective T cells is inhibited by interleukin (IL)3 and IL4 produced by disease-promoting T cells in leishmaniasis

BALB/c mice are highly susceptible to Leishmania major infection. They develop a progressive fatal disseminating disease even with a minimum infecting dose. However, these mice are able to contain the disease if they are exposed to sublethal gamma-irradiation shortly before infection. Earlier studies demonstrated that CD4+ T cells from mice which had recovered from infection (Tr) can adoptively transfer resistance. In contrast, CD4+ cells from mice with progressive disease (Ts) not only failed to protect, but can reverse the protective effect of the Tr cells. Spleen cells from BALB/c mice which had recovered from L. major infection or which had progressive disease were cultured with leishmanial antigens in vitro. The culture supernatant from spleen cells of recovered mice (TrSN) contains high levels of macrophage-activating factor (MAF) activity which can activate peritoneal macrophages to kill 51Cr-labeled P815 cells and to eliminate intracellular parasites as measured by the reduction in [3H]thymidine uptake by residual parasites released from macrophages following sodium dodecyl sulfate treatment. The MAF activity of TrSN parallels that of recombinant interferon-gamma (IFN-gamma). In contrast, culture supernatant of spleen cells from mice with progressive disease (TsSN) contains no detectable MAF but it is able to neutralize the MAF activity of TrSN. The MAF-inhibiting function of TsSN appears to be mediated by interleukin (IL)3 and IL4, since the MAF activity of TrSN and rIFN-gamma also can be inhibited by the addition of rIL3 and rIL4 but not by rIL1 or rIL2. Furthermore, the MAF-inhibiting activity of TsSN can be partially reversed by the addition of specific anti-IL3 or anti-IL4, but completely reversed by the combination of the two antibodies in vitro. These findings provide a mechanism for the immune regulation in leishmaniasis and a means by which the two subsets of CD4+ T cells influence each other through their modulation of macrophage function.

Transcription inhibition site on the M protein of vesicular stomatitis virus located by marker rescue of mutant tsO23(III) with M-gene expression vectors

The matrix (M) protein of vesicular stomatitis virus serves as an endogenous inhibitor of viral transcription, a function missing or deficient in M proteins of temperature-sensitive (ts) mutants assigned to complementation group III. Previous studies with mutant tsO23(III) and vaccinia virus M-gene expression vectors revealed that the temperature-sensitive phenotype is due to a mutation leading to substitution of phenylalanine for leucine at amino acid III, whereas loss of the major antigenic determinant (epitope 1) of the mutant M protein results from the substitution of glutamic acid for the wild-type amino acid glycine at position 21 (Y. Li, L. Luo, R. M. Snyder, and R. R. Wagner, J. Virol. 62:3729-3737, 1988). We demonstrate here that transcription inhibition activity is restored to rescued tsO23 virus only when the rescuing vaccinia virus recombinant expresses M protein with glycine and not glutamic acid at amino acid 21. These experiments indicate the importance of the conformational integrity of the amino-terminal domain in determining the capacity of the vesicular stomatitis virus M protein to down regulate endogenous transcription.