Four-layer radioimmunoassay for detection of adenovirus in stool.

A four-layer antispecies radioimmunoassay (RIA) was developed for the detection of adenovirus in stool specimens. Polystyrene beads were used as the solid phase, anti-adenovirus guinea pig immunoglobulin (1 microgram per bead) was used as the primary antibody, anti-adenovirus rabbit immunoglobulin (16 micrograms/ml) was used as the secondary antibody, and 125I-labeled sheep anti-rabbit immunoglobulin was used as the indicator antibody. A highly purified, crystallized adenovirus type 2 hexon antigen was used as the immunizing antigen for the production of hyperimmune sera. The sensitivity of the test was 1 ng of hexon protein per ml. Each of the 13 stool specimens positive for adenovirus by electron microscopy was positive for adenovirus by the RIA. Of 200 nonconcentrated stool specimens negative by electron microscopy, 14 additional specimens were positive by the RIA, increasing the detection rate from 6% by electron microscopy to 13% by the RIA. A confirmatory test was done on the RIA-positive, electron microscopy-negative specimens, and the test indicated a true specific result with each specimen. A confirmatory test was also done on each specimen with a low positive counts per minute value. The specificity of the RIA was further demonstrated by the fact that a positive result was found with only 3 of 295 specimens positive by the rotavirus RIA. In two of these three specimens, adenovirus and rotavirus were also detected simultaneously by electron microscopy, and the third specimen was from a patient with serological evidence for a dual infection. The adenovirus and rotavirus RIAs are now in a routine diagnostic laboratory, and in the 307 stool specimens tested during the first 5 months, the positive rate was 32% for rotavirus and 9.5% for adenovirus.     

Metoprolol, nifedipine, and the combination in stable effort angina pectoris

Treatment with metoprolol (100 mg twice daily), nifedipine (10 mg 3 times daily) and both drugs combined were compared for effect on clinical variables, bicycle ergometer exercise tolerance and adverse effects in a randomized double-blind, crossover study in patients with stable effort angina (n = 62). Nitroglycerin consumption and anginal attack rate as recorded in patient diaries indicated a higher antianginal efficacy (p less than or equal to 0.001) with metoprolol and combination therapy than with nifedipine monotherapy. All exercise test variables showed a significantly higher antianginal efficacy with combination therapy than with nifedipine monotherapy (15 to 26%). The combination therapy was also better than metoprolol in all exercise variables (9 to 14%), except for onset and duration of chest pain. Furthermore, metoprolol showed a higher efficacy than nifedipine in all exercise variables (7 to 23%) except total exercise time. More adverse symptoms of peripheral vasodilation were reported for nifedipine than for metoprolol (tachycardia, flushing, headache, p less than or equal to 0.05). It is concluded that combined treatment with metoprolol and nifedipine increased antianginal efficacy compared with the monotherapies, without increasing adverse effects. In effort angina, metoprolol in these doses was more effective and better tolerated than nifedipine.     

Helper activity of CD4+ αβ T cells is required for the avian γδ T cell response

We have studied the in vitro activation of chicken γδ T cells. Both splenic αβ and γδ T cells obtained from complete Freund's adjuvant-primed chickens proliferated in vitro when stimulated with mycobacterial sonicate or purified protein derivative of Mycobacterium tuberculosis. When CD4⁺ cells or αβ T cell receptor (TcR)-positive cells were removed, both the proliferation and the blast formation of γδ T cells in response to mycobacterial antigens were abrogated. The response was restored if supernatant from concanavalin A (Con A)-activated lymphocyte cultures (CAS) as a source of helper factors was added together with the specific antigen purified protein derivative. The CD4- or αβ TcR-depleted cells still proliferated in response to Con A, although a decrease of the response was observed. To analyze the γδ T cell response more specifically we stimulated peripheral blood cells with immobilized monoclonal antibodies against T cell receptor. Anti-γδ TcR antibody alone did not induce significant proliferation. When CAS was added together with the anti-γδ TcR monoclonal antibody, a strong proliferation of γδ T cells was observed. In contrast, both Vβ1- and Vβ2-expressing αβ T cells proliferated in vitro in response to stimulation with the relevant anti-TcR monoclonal antibody alone. Depletion of either Vβ1⁺ or Vβ2⁺ T cell subset alone had no negative effect on the proliferation or blast formation of γδ T cells stimulated with mycobacterial antigens. Taken together our results suggest that CD4⁺ αβ T cells (both Vβl- and Vβ2-expressing) play a role in the activation and response of chicken γδ T cells.     

Gender differences in recurrent coronary events; the FINMONICA MI register.

BACKGROUND: Male gender is an established risk factor for first myocardial infarction, but some studies have suggested that among myocardial infarction survivors, women fare worse than men. Therefore, we examined the long-term prognosis of incident myocardial infarction survivors in a large, population-based MI register, addressing gender differences in mortality as well as the number of events and time intervals between recurrent events. METHODS AND RESULTS: Study subjects included 4900 men and women, aged 25-64 years, with definite or probable first myocardial infarctions who were alive 28 days after the onset of symptoms. At first myocardial infarction, women were older and more likely to be hypertensive or diabetic than men, and had a greater proportion of probable vs definite events. After adjustment for age and geographic region, men had 1.74 times the risk of fatal coronary heart disease relative to women (hazard ratio=1.63 and 1.55 for cardiovascular disease and all-cause mortality, respectively) over an average of 5.9 years of follow-up. Number and time intervals between any recurrent event--fatal and non-fatal--did not differ by gender. CONCLUSION: These data suggest that men are far more likely to have a fatal recurrent event than women despite comparable numbers of events.     

On the response of mouse peritoneal macrophages to titanium dioxide pigments in vitro

Acid phosphatase activity and cell morphology were followed using mouse peritoneal macrophages as a toxicity test model in vitro. The cells were given titanium dioxide (TiO₂) and five titanium pigments with different coating materials in 100 μg/ml of culture medium. The cell reactions were studied from 1 to 17 days. Titanium particles inhibited the acid phosphatase activity of the cells compared to controls. In comparison to untreated cells the activity of this enzyme increased in most groups studied, being highest in the control cells (2–3.5 times) after 7 days. The titanium pigments did not cause the drastic alterations in these cells as seen with quartz and asbestos particles, but the titanium pigments were not harmless to the mouse peritoneal macrophages with the doses and culture times used.     

Viral antibodies in the sera from patients with Parkinson disease.

An assay of antibodies to 15 various viruses and mycoplasma pneumoniae was performed on the serum specimens from 441 patients with Parkinson disease and from 443 healthy controls matched by sex, age, and place of residence, or from a representative group of these matched pairs. The main finding was a higher herpes simplex complement-fixing antibody level in patients with Parkinson disease than in controls. Patients with Parkinson disease had higher herpes simplex antibody titers more often than did their matched controls, and the matched controls, respectively, had low titers more often than the patients. The mean herpes simplex antibody titer (log2) of the patients (4.9) was significantly higher than that of controls (4.6) (p less than 0.01). This difference was also demonstrable when matched pairs were analysed for paired differences of herpes simplex antibody titers. For other viral CF and HI antibodies studied and for mycoplasma pneumoniae CF antibody, there were no significant differences either in the mean titers or in the distribution of individual titer values between the patients with Parkinson disease and the matched controls.