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.