Antibody-mediated protection against Brucella abortus in BALB/c mice at successive periods after infection: variation between virulent strain 2308 and attenuated vaccine strain 19.

In BALB/c mice antibodies specific for the O polysaccharide (OPS) as well as T lymphocytes mediate protective immunity to Brucella abortus. We performed quantitative analyses of isotypes of OPS antibodies generated during primary infections, and tested the protective qualities of antisera at successive stages of infection against B. abortus strain 2308, representative of the wild type, and attenuated vaccine strain 19. IgM antibodies predominated during the first 3-4 weeks of infection. IgG3 antibodies increased slowly for the first 3 weeks but then rose rapidly and persisted at high levels (> 300 micrograms/ml). IgG1, IgG2a and IgG2b antibodies had increased slightly by week 4 and then remained at low to moderate levels (< 70 micrograms/ml). Week 2 serum pools (IgM high, IgG3 low or undetectable) transferred substantial protection against 2308 (> or = 1 log unit) which increased relatively little (to 1.2-1.5 log units) with later sera that were high in IgG antibodies. In contrast, week 2 sera conferred low levels of protection against 19 (< 0.6 log units), but protection was dramatically increased (to > or = 2.3 log units) with sera obtained 1 week later that had slightly increased IgG antibodies. Monoclonal IgM antibodies also provided better protection against 2308 than 19, while monoclonal IgG3 antibodies protected much better against 19. Strain 19 opsonized with antibodies taken at any stage of infection was killed within normal macrophages, whereas comparably opsonized 2308 underwent intracellular replication. Phagocytosis of 2308 was better than of 19 when brucellae were opsonized with either polyclonal IgM or IgG3 antibodies, and the difference between strains was more extreme following IgM opsonization. The data suggest an explanation for differences in the growth curves of 2308 and 19 in spleens of BALB/c mice. Higher numbers achieved by 19 at week 2 could result from extracellular replication owing to ineffectual opsonization by IgM antibodies, while the precipitous decline of 19 beginning at week 3 could be caused by the increase in more effective IgG3 opsonins that facilitate its rapid intracellular destruction.     

The influence of negative staining on the infectivity of vaccinia virus

Summary The specific infectivity of [³H]-thymidine-labeled vaccinia virus in electron microscopic specimens after negative staining has been determined by correlating infectivity with radioactivity counts as the criterion for morphological preservation.     

Can subjects with a positive allergen skin test be selected by a short questionnaire?

The objective was to evaluate a postal questionnaire screening procedure for selection of subjects with positive reactions to skin prick tests with common allergens. The project consisted of a screening, with subsequent skin prick test of two selected groups. The setting was the Glostrup Population Studies institute in Copenhagen, Denmark. Participants in the screening included 8000 subjects, aged 15–69 years. The subjects were randomly selected from the population of western Copenhagen County, Denmark. From the 6998 respondents (87.5%), 793 subjects were randomly selected (Random Group), and 788 subjects were chosen on the basis of their answers to the questionnaire (Symptom Group). Both groups were invited to take skin prick tests. Attendance rates were 75.5% (Random Group) and 80.6% (Symptom Group).
The main outcome measures were responses (yes or no) to the specific questions and the subjects' skin reaction (positive or negative). The association between symptoms and skin reactivity, adjusted for the effects of sex and age, was summarized by odds ratios. Symptoms on exposure to allergens were highly associated with positive skin reactivity. In the Symptom Group the percentage of subjects with at least one positive skin reaction was 57.7%, which was twice as much (28.4%) as in the Random Group. The results show that it was possible to select a group with high skin reactivity on the basis of the symptoms reported in the screening. Questions about exposure to allergens were the most appropriate for selection of this group.     

Thermoregulatory responses to intermittent exercise are influenced by knit structure of underwear

Summary The purpose of this study was to evaluate the role of knit structure in underwear on thermoregulatory responses. Underwear manufactured from 100% polypropylene fibres in five different knit structures (1-by-1 rib, fleece, fishnet, interlock, double-layer rib) was evaluated. All five underwear prototypes were tested as part of a prototype clothing system. Measured on a thermal manikin these clothing systems had total thermal resistances of 0.243, 0.268, 0.256, 0.248 and 0.250 m² · K · W^–1, respectively (including a value for the thermal resistance of the ambient environment of 0.104 m² · K · W^–1). Human testing was done on eight male subjects and took place at ambient temperature (T _a)=5°C, dew point temperature (T _dp)=–3.5° C and air velocity (V _a)=0.32 m · s^–1. The test comprised a repeated bout of 40-min cycle exercise (315 W · m^–2; 52%, SD 4.9% maximal oxygen uptake) followed by 20 min of rest (62 W · m^–2). The oxygen uptake, heart rate, oesophageal temperature, skin temperature,T _a,T _dp at the skin and in the ambient air, onset of sweating, evaporation rate, non-evaporated sweat accumulated in the clothing and total evaporative loss of mass were measured. Skin wettedness was calculated. The differences in knit structure of the underwear in the clothing systems resulted in significant differences in mean skin temperature, local and average skin wettedness, non-evaporated and evaporated sweat during the course of the intermittent exercise test. No differences were observed over this period in the core temperature measurements.The views, opinions and/or findings in this report are those of the authors and should not be construed as an official Department of the Army position, policy, or decision, unless so designated by other official documentation     

Intranasal and inhaled fluticasone propionate for pollen-induced rhinitis and asthma

BACKGROUND: Studies suggest that nasal treatment might influence lower airway symptoms and function in patients with comorbid rhinitis and asthma. We investigated the effect of intranasal, inhaled corticosteroid or the combination of both in patients with both pollen-induced rhinitis and asthma. METHODS: A total of 262 patients were randomized to 6 weeks' treatment with intranasal fluticasone propionate (INFP) 200 microg o.d., inhaled fluticasone propionate (IHFP) 250 microg b.i.d., their combination, or intranasal or inhaled placebo, in a multicentre, double-blind, parallel-group study. Treatment was started 2 weeks prior to the pollen season and patients recorded their nasal and bronchial symptoms twice daily. Before and after 4 and 6 weeks' treatment, the patients were assessed for lung function, methacholine responsiveness, and induced sputum cell counts. RESULTS: Intranasal fluticasone propionate significantly increased the percentages of patients reporting no nasal blockage, sneezing, or rhinorrhoea during the pollen season, compared with IHFP or intranasal or inhaled placebo. In contrast, only IHFP significantly improved morning peak-flow, forced expiratory volume in 1 second (FEV1) and methacholine PD20, and the seasonal increase in the sputum eosinophils and methacholine responsiveness. CONCLUSIONS: In patients with pollen-induced rhinitis and asthma, the combination of intranasal and IHFP is needed to control the seasonal increase in nasal and asthmatic symptoms.     

Epidermal growth factor and insulin short‐term increase hPepT1‐mediated glycylsarcosine uptake in Caco‐2 cells

Aims: Little is known about the physiological regulation of the human intestinal di/tri‐peptide transporter, hPepT1. In the present study we evaluated the effects of epidermal growth factor (EGF) and insulin on hPepT1‐mediated dipeptide uptake in the intestinal cell line Caco‐2. Methods: Caco‐2 cells were grown on filters for 23–27 days. Apical dipeptide uptake was measured using [¹⁴C]glycylsarcosine([¹⁴C]Gly‐Sar). HPepT1 mRNA levels were investigated using RT‐PCR, cytosolic pH was determined using the pH‐sensitive fluorescent probe BCECF. Results: Basolateral application of EGF increased [¹⁴C]Gly‐Sar uptake with an ED₅₀ value of 0.77 ± 0.25 ng mL^?1 (n = 3?6) and a maximal stimulation of 33 ± 2% (n = 3?6). Insulin stimulated [¹⁴C]Gly‐Sar uptake with an ED₅₀ value of 3.5 ± 2.0 ng mL^?1 (n = 3?6) and a maximal stimulation of approximately 18% (n = 3?6). Gly‐Sar uptake followed simple Michaelis‐Menten kinetics. K_m in control cells was 0.98 ± 0.11 mM (n = 8) and V_max was 1.86 ± 0.07 nmol cm^?2 min^?1 (n = 8). In monolayers treated with 200 ng mL^?1 of EGF, K_m was 1.11 ± 0.05 mM (n = 5) and V_max was 2.79 ± 0.05 nmol cm^?2 min^?1 (n = 5). In monolayers treated with 50 ng mL^?1 insulin, K_m was 1.03 ± 0.08 mM and V_max was 2.19 ± 0.06 nmol cm^?2 min^?1 (n = 5). Kinetic data thus indicates an increase in the number of active transporters, following stimulation. The incrased Gly‐Sar uptake was not accompanied by changes in hPepT1 mRNA, nor by measurable changes in cytosolic pH. Conclusions: Short‐term stimulation with EGF and insulin caused an increase in hPepT1‐mediated uptake of Gly‐Sar in Caco‐2 cell monolayers, which could not be accounted for by changes in hPepT1 mRNA or proton‐motive driving force.     

D/D Translocations in Males Examined for Military Service

Three males with Robertsonian translocations were found in a sample of 1115 males examined for military service. One was a 14/15 translocation, and two were 13/14 translocations. One was spontaneous and two familial. The segregation rate of the translocations did not deviate significantly from unity in the sibships where the mother was the carrier, whereas all five children had the translocation in the two sibships where the father was the carrier. There were no abortions and no aneuploid chromosome abnormalities in the progeny of carriers with D/D translocation. There were no indications of any association between the D/D translocations and physical or mental development.