Nasal histamine challenge in nonallergic and allergic subjects evaluated by acoustic rhinometry

Nasal patency shows spontaneous variations but is influenced by a number of factors like exercise and allergic conditions. Nasal histamine challenge has been used to define nasal hypersensitivity. We have applied acoustic rhinometry as a new objective method to study the spontaneous variations of the nasal mucosa and its response to histamine challenge in 12 nonallergic subjects and 12 subjects with nasal allergy to pollen, but out of the pollen season. Measurements of the minimum cross-sectional area and the volume of the nasal cavities were done every 15 min for 6 h. More pronounced spontaneous variations, defined by the coefficient of variation of the measurements, were encountered in the allergic than in the nonallergic subjects, especially with regard to the minimum cross-sectional areas in the nasal cavities (P < 0.02). Allergic subjects showed increased sensitivity to histamine, as compared with nonallergic subjects, during low-concentration (0.1%) challenge (P < 0.05) and a prolonged effect of histamine challenge (P = 0.01). Antihistamine (cetirizine) had a significant effect on the histamine-induced symptoms and decrease of nasal dimensions during histamine challenge, but no significant effect on pollen-induced changes. In the allergic group, the decrease in minimum area during allergen provocation correlated with the level of specific IgE (r = 0.81; P = 0.0015).     

Isolation of HIV from cultures of purified CD4+ lymphocytes.

Isolation of HIV from cultures of CD4+ lymphocytes purified from peripheral blood by indirect panning was optimized and evaluated. Infectious HIV was isolated by single isolation attempts in 98% of 102 HIV-antibody-positive patients (55 had AIDS or ARC and 47 were clinically healthy). The average culture time required for positive cultures was largely independent of the CD4 count of the patients and 87% of the positive isolation cultures from both groups of patients became positive within 14 days of culture. An evaluation of the possible influence of media additives on propagation of HIV showed that: amphotericin-B had a suppressive effect on HIV replication at concentrations recommended for anti-fungal activity; recombinant and human interleukin-2 were equally suitable for both isolation cultures and for propagation of HIV, and polybrene, at a concentration of 2 micrograms/ml in the culture medium had a beneficial effect.     

Oncogenic retrovirus from spontaneous murine osteomas. II. Molecular cloning and genomic characterization

An N-ecotropic murine leukemia virus (OA MuLV), originally isolated from spontaneous osteomas of strain 101 mice, was molecularly cloned. The virus induces osteomas, osteopetrosis, and malignant lymphomas in NMRI mice. The cloned virus was analyzed by heteroduplex analysis, restriction enzyme mapping, and oligonucleotide mapping. The data show a very close relationship to the endogenous Akv prototype virus with some differences in the gag and the env region. The nucleotide sequence of the U3 region of OA MuLV LTR revealed a structure within the presumable enhancer region very similar to the U3 sequences of the FBJ murine sarcoma virus and its associated helper virus. The significance of these specific structures for the oncogenicity of the virus and the development of the typical disease pattern is discussed.     

Biological behavior of tumors and associated retroviremia in cats inoculated with Snyder-Theilen fibrosarcoma virus and the phenomenon of tumor recurrence after primary regression.

The fate of tumors and associated retroviremia was studied in 111 cats infected with the Snyder-Theilen strain of feline sarcoma virus (FeSV). Tumors appeared at the site of inoculation within 7 to 10 days. A retroviremia, due mainly to the associated feline leukemia virus helper virus (FeLV-helper), developed at the same time as tumors. Of the cats, 44 developed progressively growing tumors and therefore had to be killed, and 67 developed tumors that regressed. There was a strong correlation between the persistence of the accompanying retroviremia and the growth of the tumors. The 44 cats with progressively growing fibrosarcomas remained retroviremic until death. Conversely, 53 of the 67 cats with solitary, regressing tumors were only transiently retroviremic. Tumor regression in these cats paralleled the disappearance of retrovirus from the blood. The fate of tumors and retroviremia was not always the same, however. Twelve cats remained persistently retroviremic after all signs of gross tumors disappeared. Two other kittens became nonviremic within 20 days after inoculation, yet tumors continued to grow and even metastasize for another 3 to 5 weeks before regressing. Fibrosarcomas recurred 3 weeks to 8 months later in 8 of 12 persistently retroviremic cats with regressed tumors. Although the blood and bone marrow from these cats contained predominantly FeLV-helper, tumor cells yielded both FeSV and FeLV-helper. Of 53 animals, 3 developed recurrent fibrosarcomas 5 weeks to 8 months after all signs of tumors and retroviremia had disappeared. Cells cultured from these tumors appeared initially like normal fibroblasts and were virus nonproducers. After one to three passages in culture, however, cells became malignantly transformed and replicated both FeSV and FeLV-helper. Cultures of the bone marrow from these and other nonviremic cats with regressed tumors yielded only FeLV-helper.     

Experimental immunization with Pseudomonas aeruginosa alginate induces IgA and IgG antibody responses.

We tried experimentally to induce a specific antibody response against Pseudomonas aeruginosa locally in the airways and systemically in rats by three different routes of immunization; intragastric feeding, intratracheal inoculation or subcutaneous vaccination. Three groups of rats were immunized with live mucoid P. aeruginosa PAO 579 by intragastric feeding or with killed PAO 579 intratracheally or subcutaneously. Three other groups were immunized with purified P. aeruginosa alginate either by intragastric feeding, intratracheally or subcutaneously. At weekly intervals for four weeks animals were sacrificed and serum and bronchial fluid were obtained. The specific IgA and IgG antibody response in lavage fluid and serum was measured. Only traces of antibodies could be detected in the bronchial lavage fluids. Anti-alginate IgA and IgG antibodies developed in all rats immunized with alginate but no antibodies against other P. aeruginosa antigens were detected. The highest IgA and IgG titer against alginate was induced by the subcutaneous immunization. IgA and IgG antibodies against other P. aeruginosa antigens developed in rats immunized with liver and sonicated bacteria. The highest IgA and IgG titers were obtained after intratracheal and subcutaneous immunization with sonicated bacteria. The present work has shown that IgA and IgG antibodies develop with high specificity after immunization. The different titers obtained do not necessarily reflect different degrees of protection.     

Separated fraternal twins: Resemblance for cognitive abilities

Thirty-four pairs of Swedish fraternal twins separated in the first 10 years of life were administered 12 tests of cognitive abilities. The average age of the twins was 59 years. Nineteen pairs were separeted before the first year of life and 26 pairs (76%) were separated by the age of 5 years. Moderate positive twin correlations were found for all tests, reaching significance for Raven's Progressive Matrices and Word Beginnings and Endings. A twin correlation of 0.52 emerged for the first principal component (a measure of general ability). Moderate correlations were found for Spatial Ability and for Verbal Ability/Perceptual Speed factors; for the Memory factor the correlation was lower. The effect of early environment on cognitive ability was assessed by analyzing the association between a degree of separation index and twin resemblance. The importance of the separation measures taken individually was also examined. Some significant effects were found, but these were consistently in a counterintuitive direction: Twins separated earlier weremore similar than those separated later.This research was supported in part by National Institute on Aging Grant AG-01592.     

Feline coronavirus serotypes 1 and 2: seroprevalence and association with disease in Switzerland

To determine the prevalence of antibodies to feline coronavirus (FCoV) serotypes 1 and 2 in Switzerland and their association with different disease manifestations, a serological study based on immunofluorescence tests was conducted with Swiss field cats using transmissible gastroenteritis virus (TGEV), FCoV type 1 and FCoV type 2 as antigens. A total of 639 serum samples collected in the context of different studies from naturally infected cats were tested. The current study revealed that, with an apparent prevalence of 83%, FCoV serotype 1 is the most prevalent serotype in Switzerland. FCoV type 1 viruses induced higher antibody titers than FCoV type 2, and were more frequently associated with clinical signs and/or feline infectious peritonitis. The antibody development in seven cats experimentally infected with FCoV type 1 revealed that, with progressing duration of infection, antibodies to FCoV type 1 significantly increased over those to FCoV type 2. There was a significant relationship between antibody titers against TGEV, FCoV 1, and FCoV 2 and TGEV antigen detected the highest proportion of seropositive cats. We conclude that a vaccine against FCoV should be based on FCoV type 1-related antigens and that for serodiagnosis of FCoV infection TGEV should be used to attain the highest diagnostic efficiency. When serology is used in addition to clinical signs, hematology, and clinical chemistry results as an aid to diagnose clinical FIP, TGEV shows a diagnostic efficiency equal to that of a FCoV antigen.     

Glucose Ingestion Attenuates Interleukin-6 Release from Contracting Skeletal Muscle in Humans

To examine whether glucose ingestion during exercise affects the release of interleukin-6 (IL-6) from the contracting limb, seven men performed 120 min of semi-recumbent cycling on two occasions while ingesting either 250 ml of a 6.4 % carbohydrate (GLU trial) or sweet placebo (CON trial) beverage at the onset of, and at 15 min intervals throughout, exercise. Muscle biopsies obtained before and immediately after exercise were analysed for glycogen and IL-6 mRNA expression. Blood samples were simultaneously obtained from a brachial artery and a femoral vein prior to and during exercise and leg blood flow was measured by thermodilution in the femoral vein. Net leg IL-6 release, and net leg glucose and free fatty acid (FFA) uptake, were calculated from these measurements. The arterial IL-6 concentration was lower (   P < 0.05  ) after 120 min of exercise in GLU, but neither intramuscular glycogen nor IL-6 mRNA were different when comparing GLU with CON. However, net leg IL-6 release was attenuated (   P < 0.05  ) in GLU compared with CON. This corresponded with an enhanced (   P < 0.05  ) glucose uptake and a reduced (   P < 0.05  ) FFA uptake in GLU. These results demonstrate that glucose ingestion during exercise attenuates leg IL-6 release but does not decrease intramuscular expression of IL-6 mRNA.     

Numerical Simulation and Experimental Validation of Blood Flow in Arteries with Structured-Tree Outflow Conditions

Blood flow in the large systemic arteries is modeled using one-dimensional equations derived from the axisymmetric Navier–Stokes equations for flow in compliant and tapering vessels. The arterial tree is truncated after the first few generations of large arteries with the remaining small arteries and arterioles providing outflow boundary conditions for the large arteries. By modeling the small arteries and arterioles as a structured tree, a semi-analytical approach based on a linearized version of the governing equations can be used to derive an expression for the root impedance of the structured tree in the frequency domain. In the time domain, this provides the proper outflow boundary condition. The structured tree is a binary asymmetric tree in which the radii of the daughter vessels are scaled linearly with the radius of the parent vessel. Blood flow and pressure in the large vessels are computed as functions of time and axial distance within each of the arteries. Comparison between the simulations and magnetic resonance measurements in the ascending aorta and nine peripheral locations in one individual shows excellent agreement between the two. © 2000 Biomedical Engineering Society. PAC00: 8719Uv     

Pseudodicentric chromosome 18 diagnosed by chromosome painting and primed in situ labelling (PRINS).

We report on a newborn white male infant with marked dysmorphic features and various congenital malformations. The initial clinical evaluation showed Crouzon-like features as well as some features of trisomy 18 syndrome and trisomy 13 syndrome. The results from conventional cytogenetic analysis showed a structurally abnormal chromosome replacing one normal chromosome 18, but only by applying molecular cytogenetic methods could the architecture of this abnormal chromosome be characterised clearly. The primed in situ labelling (PRINS) technique, using a newly synthesised alpha 18 oligonucleotide, showed the dicentric pattern and direct chromosome painting established the origin to be from chromosome 18. The combination of conventional cytogenetics and molecular cytogenetics showed the karyotype in the proband to be 45,XY,-14,-18,-21,+t(14;21),+psu dic(18) (qter-->cen-->p11.3: :p11.3-->psu cen-->qter). This was supported by molecular analysis using chromosome 18 specific DNA markers, which showed the paternal origin of the abnormal chromosome.