Increased environmental gamma-ray dose rate during precipitation: a strong correlation with contributing air mass.

It has long been observed that the environmental gamma-ray dose rate increases noticeably during precipitation intervals. This increase, due to the presence of radon progeny in the rain droplets (or snow flakes), can affect the reliability of the monitoring of artificial radioactivity and long term estimates of exposure to ambient natural radionuclides in surveillance network. Predicting the amplitude of the dose increase has been shown to be surprisingly challenging. In this work, standard air mass back trajectory analysis is used to show that the amplitude of the increase can be quantitatively linked to the history of the air mass where the precipitation is occurring. Furthermore, we show how back trajectory analysis, environmental gamma and rain data can be used to obtain estimations of relative radon emanation rates for locations far from the actual point of detection.

Murine renal cell carcinoma: evaluation of a dendritic-cell tumour vaccine.

OBJECTIVE: To use a murine model of renal cell carcinoma (RCC), Renca, to aid in developing a dendritic cell (DC)-mediated tumour vaccine for RCC; as conventional therapy has been unsuccessful for RCC and therapy using immune modulators has had limited success, novel therapies enhancing further the immune system must be developed. MATERIALS AND METHODS: DCs were obtained from mouse bone marrow enriched for the haematopoietic progenitors, and cultured in the presence of interleukin-4 and granulocyte macrophage-colony stimulating factor. In vivo vaccines and in vitro proliferation assays were used to assess ability of the DCs to present tumour antigen. RESULTS: The presence of DCs was confirmed in the cultures by fluorescent-activated cell sorting analysis. In vivo, tumour-bearing animals receiving tumour extract-pulsed DCs as a vaccine showed a two to threefold reduction in tumour growth at day 12 and day 16 but no significant difference at day 28. In vitro, tumour extract-pulsed DCs stimulated significant proliferation of splenocytes from naive animals but not tumour-bearing animals. In addition, splenocytes from tumour-bearing animals had an attenuated immune response in vitro. CONCLUSION: These results show that it is possible to use the DC vaccine to modulate the immune response to achieve an antitumour effect, but further manipulation of the DC vaccine may be needed to overcome the tumour-induced immune suppression.

Orbital infarction and melting in a patient with systemic lupus erythematosus.

OBJECTIVE: To present a patient with systemic lupus erythematosus who developed infarction and melting of the orbit secondary to her systemic disease. DESIGN: A case report. PARTICIPANT: A 61-year-old white woman with a 5-year history of systemic lupus erythematosus. METHODS: The patient presented with left orbital pain, limitation of extraocular movements, and a fistula from the ethmoid sinus to the upper eyelid. A detailed examination with computerized tomography, ultrasound, and a comprehensive medical evaluation with laboratory testing was performed. Histopathologic analysis with special stains of the orbital tissues was also performed. RESULTS: Histopathologic examination of the biopsy specimens revealed the features of an inflammatory process involving the orbit, similar to a panniculitis. These include a lymphocytic reaction with a predominance of plasma cells, vasculitis with occlusion, and thickening of the vessel walls, necrosis, and hyalinization of fat. CONCLUSION: This is a unique case in which infarction and melting of the entire orbital structures occurred in the presence of systemic lupus erythematosus. The underlying disease process is a lupus-related panniculitis. The authors stress that this is a very rare entity and that other diseases should be ruled out before entertaining this diagnosis.

Persistent infection of human oligodendrocytic and neuroglial cell lines by human coronavirus 229E.

Human coronaviruses (HuCV) cause common colds. Previous reports suggest that these infectious agents may be neurotropic in humans, as they are for some mammals. With the long-term aim of providing experimental evidence for the neurotropism of HuCV and the establishment of persistent infections in the nervous system, we have evaluated the susceptibility of various human neural cell lines to acute and persistent infection by HuCV-229E. Viral antigen, infectious virus progeny and viral RNA were monitored during both acute and persistent infections. The astrocytoma cell lines U-87 MG, U-373 MG, and GL-15, as well as neuroblastoma SK-N-SH, neuroglioma H4, and oligodendrocytic MO3.13 cell lines, were all susceptible to an acute infection by HuCV-229E. The CHME-5 immortalized fetal microglial cell line was not susceptible to infection by this virus. The MO3.13 and H4 cell lines also sustained a persistent viral infection, as monitored by detection of viral antigen and infectious virus progeny. Sequencing of the S1 gene from viral RNA after approximately 130 days of infection showed two point mutations, suggesting amino acid changes during persistent infection of MO3.13 cells but none for H4 cells. Thus, persistent in vitro infection did not generate important changes in the S1 portion of the viral spike protein, which was shown for murine coronaviruses to bear hypervariable domains and to interact with cellular receptor. These results are consistent with the potential persistence of HuCV-229E in cells of the human nervous system, such as oligodendrocytes and possibly neurons, and the virus's apparent genomic stability.

Relating objective measurements to expert evaluation of voice quality in Western classical singing: critical perceptual parameters.

Communication between voice pedagogues and voice scientists is often impeded by reliance on colorful and sometimes seemingly contradictory descriptions of vocal production and voice quality. A recent study identified perceptual criteria which are generally used by voice experts for the assessment of voice quality in classical singing. In the present study, performances by singers of various voice types and levels of accomplishment were rated by panels of expert voice teachers according to four perceptual criteria: "resonance/ring," "color/warmth," "clarity/focus," and "appropriate vibrato." Subjective ratings were related to objective measurements taken from acoustic analysis of the voice signal. Possible acoustic correlates of critical perceptual parameters influencing judgments of voice quality were thus identified. Results could help bridge the terminology gap between vocal artists and scientists, and help to promote understanding of the way in which acoustic stimuli influence perception of voice quality.

Characterization of the expression and immunogenicity of the ns4b protein of human coronavirus 229E.

Sequencing of complementary DNAs prepared from various coronaviruses has revealed open reading frames encoding putative proteins that are yet to be characterized and are so far only described as nonstructural (ns). As a first step in the elucidation of its function, we characterized the expression and immunogenicity of the ns4b gene product from strain 229E of human coronavirus (HCV-229E), a respiratory virus with a neurotropic potential. The gene was cloned and expressed in bacteria. A fusion protein of ns4b with maltose-binding protein was injected into rabbits to generate specific antibodies that were used to demonstrate the expression of ns4b in HCV-229E-infected cells using flow cytometry. Given a previously reported contiguous five amino acid shared region between ns4b and myelin basic protein, a purified recombinant histidine-tagged ns4b protein and (or) human myelin basic protein were injected into mice to evaluate whether myelin-viral protein cross-reactive antibody responses could be generated. Each immunogen induced specific but not cross-reactive antibodies. We conclude that ns4b is expressed in infected cells and is immunogenic, although this does not involve amino acids shared with a self protein, at least in the experimental conditions used.

A recombinant single chain antibody neutralizes coronavirus infectivity but only slightly delays lethal infection of mice.

The variable region genes of a murine anti-coronavirus monoclonal antibody (mAb) were joined by assembly polymerase chain reaction and expressed in Escherichia coli in a single chain variable fragment (scFv) configuration. After induction of expression, the expected 32-kDa protein was identified by Western immunoblotting with specific rabbit anti-idiotype antibodies. The scFv fragments were purified from soluble cytoplasmic preparations by affinity chromatography on nickel agarose, which was possible with an N-terminal but not with a C-terminal histidine tag. Purified scFv fragments retained the antigen-binding properties of the parental antibody, could inhibit its binding to viral antigens with apparently higher efficiency than monovalent antigen-binding (Fab) fragments, but neutralized viral infectivity with lower efficiency (about sevenfold at a molar level). To evaluate the usefulness of these smaller and less immunogenic molecules in the treatment of viral diseases, mice were treated with purified recombinant scFv fragments and challenged with a lethal viral dose. A small delay in mortality was observed for the scFv-treated animals. Therefore, even though the scFv could neutralize viral infectivity in vitro, the same quantity of fragments that partially protected mice in the form of Fab only slightly delayed virus-induced lethality when injected as scFv fragments, probably because of a much faster in vivo clearance: the biologic half-life was estimated to be about 6 min. Since a scFv derived from a highly neutralizing and protective mAb is only marginally effective in the passive protection of mice from lethal viral infection, the use of such reagents for viral immunotherapy will require strategies to overcome stability limitations.

Laryngotracheal trauma.

Isolated trauma to the airway is infrequent yet potentially life-threatening. The larynx and cervical trachea are vulnerable to external forces, whether penetrating or blunt, as well as internal injuries from endotracheal or nasogastric intubation and to thermal burns from the inhalation of fumes or the ingestion of caustic substances.

Expression of nitric oxide synthase in the human nasal mucosa.

The nasal mucosa plays an important role in defense of the lung against harmful agents. It has been suggested that this is partly mediated by the production of nitric oxide (NO). We have investigated the localization of the messenger ribonucleic acids (MRNAs) for human endothelial NO synthase (Type III NOS) and inducible NO synthase (Type II NOS) and the immunoreactivities of these enzymes in human nasal mucosa by immunohistochemistry, in situ hybridization, and reduced nicotinamide adenine diphosphate (NADPH) diaphorase histochemistry. Inferior nasal turbinates were obtained from 27 patients at the time of surgery for local disease. Strong immunostaining for Type III NOS was localized to vascular endothelium, surface epithelium, and submucosal glands in all subjects. Moderate immunostaining for Type II NOS was seen in surface epithelium; glandular, inflammatory, and vascular endothelial cells; and smooth-muscle cells in the specimens from patients with chronic rhinitis only. In situ hybridization showed expression of the mRNA for Type III NOS in similar sites to those shown by immunohistochemistry, whereas the mRNA for Type II NOS was predominantly localized to inflammatory cells. The sites of NOS expression were further confirmed by NADPH histochemical staining. These findings demonstrate the cellular expression of NOS in the human nasal mucosa and suggest a possible role for Types II and III NO synthase in the regulation of blood flow, nasal secretion, and ciliary movement in health and disease.

The immunological basis of nasal polyp formation.

Forty-six patients were studied to assess the role of immunological factors in the formation of nasal polyps. Total IgE levels did not correlate with positive skin testing and were generally higher in polyp sac fluid than in corresponding sera. Asthmatics had significantly higher IgE levels in both serum and polyp fluid than nonasthmatics. Specific IgE (RAST) found in polyp specimens could not be detected by conventional skin or serum testing in nine of 15 patients. By direct immunofluorescence IgE was present in 81% of polyp specimens compared with 13% in mucosal controls. These data indicate that nasal polyp formation may be an IgE mediated disease process and conventional skin or serum testing may not detect this local allergic process.