Enhanced sensitivity for detection of coronary artery disease by addition of atropine to dobutamine stress echocardiography.

Patients undergoing dobutamine stress echocardiography often take beta antagonists which limit heart rate response and sensitivity in the test for detection of coronary artery disease. The aim of this study was to assess the effect of the addition of atropine to dobutamine stress echocardiography on clinical, electrocardiographic and echocardiographic outcomes. Dobutamine stress echocardiography was performed starting at and increasing every 3 minutes with 10 micrograms/kg/min to a maximum of 40 micrograms/kg/min (stage 4), which was continued for 6 minutes. In patients not achieving 85% predicted maximal exercise heart rate and in whom the test was not judged positive on echocardiographic or electrocardiographic criteria, atropine (0.25 mg intravenously, repeated up to a maximum of 1 mg if necessary) was added and dobutamine continued for up to a further 5 minutes, or until an adequate heart rate was achieved or the test was stopped because of chest pain or electrocardiographic changes. Of 80 consecutive patients undergoing dobutamine stress echocardiography within 2 weeks of coronary angiography, 49 required atropine (group A) and 31 required only dobutamine (group B). After dobutamine alone, heart rate (mean +/- SD) was higher in group B than in group A: 129 +/- 20 vs 90 +/- 18 beats/min, p less than 0.0001; but after the addition of atropine, heart rate in group A increased to 120 +/- 20 beats/min. Overall sensitivity for the detection of coronary disease was 70%, 95% confidence interval (CI) 55 to 83%; after the addition of atropine, sensitivity for group A was 65%, 95% CI 45 to 81%; in group B, sensitivity was 81%, 95% CI 54 to 96%.(ABSTRACT TRUNCATED AT 250 WORDS)

Dobutamine stress echocardiography before and after coronary angioplasty.

Myocardial function was assessed by stress echocardiography in 28 patients before and after successful elective coronary angioplasty. Dobutamine stress echocardiography was performed using up to 40 micrograms/kg/min, followed by the addition of atropine in 20 patients to achieve 85% of the predicted maximal exercise heart rate. The initial studies were performed 1 day before and the second ones within 3 days (mean 1.3) after angioplasty. Peak heart rates and systolic blood pressures were the same for the 2 studies. The frequency of dobutamine-induced new wall motion abnormalities decreased from 20 (71%) before to 4 (14%) after angioplasty (p less than 0.0001). Before angioplasty, wall motion score index (an indicator of left ventricular wall motion, an increase in which indicates impaired wall motion due to myocardial ischemia) increased from 1.06 at rest to 1.23 at peak stress (p less than 10(-6)), but there was no significant increase in this index in the study after angioplasty. Before angioplasty, 14 patients (50%) developed chest pain during the stress test compared with 6 (21%) after angioplasty (p = 0.05), and before angioplasty, the stress test was stopped before the target heart rate was achieved, because of symptoms, ST-segment change or severe new wall motion abnormality in 14 patients compared with 7 after angioplasty (p = 0.09). Thus, early after angioplasty there is a reduction in myocardial ischemia as assessed by dobutamine stress echocardiography.

Enzyme electrophoresis as an alternative method for separating the sympatric Leishmania vectors Phlebotomus papatasi and Phlebotomus langeroni (Diptera: Psychodidae).

Trials were conducted to determine the accuracy of separating the sympatric sand fly species Phlebotomus papatasi (Scopoli) and P. langeroni Nitzulescu by means of cellulose acetate enzyme electrophoresis. Malic enzyme, phosphoglucomutase, 6-phosphogluconate dehydrogenase, and fumarate hydratase were each evaluated in laboratory-reared and field-collected populations of the two species. Each of the four enzyme-based identifications was highly sensitive (greater than 97%) and specific (greater than 93%). Identifications based upon fumarate hydratase were in perfect agreement with morphological identifications, and evidence was obtained which indicates that this enzyme may be the most stable of the four enzymes tested. The application of enzyme-based vector identification is discussed in relation to classical and novel survey procedures for Leishmania promastigote detection in sand flies.

Feeding patterns of Phlebotomus papatasi and Phlebotomus langeroni (Diptera: Psychodidae) in El Agamy, Egypt.

Blood meals from 602 Phlebotomus papatasi (Scopoli) and 49 Phlebotomus langeroni Nitzulescu were collected in El Agamy, Egypt, and were identified using counterimmunoelectrophoresis. Blood meals were tested against specific antisera of eight vertebrate hosts (human, cat, dog, rat, sheep, goat, general avian, and general bovine). Of 597 P. papatasi collected indoors, 594 contained human blood and three had mixed blood meals (human-dog, human-rat, and human-avian). Four of five P. papatasi collected outdoors contained human blood and one contained avian blood. All 39 P. langeroni collected indoors had fed on humans. Six of 10 outdoor-collected P. langeroni had fed on human blood, 2 on dog, 1 on cat, and 1 on rat blood. Both P. papatasi and P. langeroni feed predominantly on humans in El Agamy, Egypt. The documented feeding on humans and dogs by P. langeroni supports the role of this species as the primary vector of visceral leishmaniasis at the El Agamy focus.

Estimates of Egyptian culcine longevity in nature altered by fluctuations in biting population density.

Estimates of vectorial capacity (VC) depend upon longevity of mosquito field populations, and expected longevity is estimated from the parity rate of the population. Seasonal variation in parity rates confound estimates of longevity which may not reflect actual population survival but are induced by changes in the rate of emergence of female mosquitoes. By comparing parity rates and biting activity in natural population of 2 Culicine mosquitoes, Culex pipiens and Cx. antennatus, we found that parity rate was low in the beginning of the season and high at the end. Parity rate appeared least affected during the weeks with maximal daily biting activity. We conclude that estimates of VC are most accurately determined for the two vector species studied when mosquito biting activity is maximal.

Heterozygote deficiency in natural populations of Aedes caspius Pallas from Egypt.

Aedes caspius Pallas populations from the Mediterranean regions are genetically highly polymorphic, and may diverge into 2 genetically isolated forms. We examined the genetic structure of 3 mosquito populations from Faiyum oasis, using starch gel electrophoresis at 8 gene loci, from which only one was monomorphic. Genetic variability was high (A = 1.97; H = 0.12; P = 54.2, 66.7). Eleven out of 16 population--enzyme combinations with variability exhibited heterozygote deficiency from Hardy--Weinberg expectations. These results suggest that tested populations represent a mosquito complex, although no genetic divergence was detected (D = 0.012) since presumed sympatric gamodemes were sampled as a single population. It is of prime importance to detect cryptic gamodemes and to elucidate the present status of Ae. caspius, as this may greatly influence control strategies.

Anopheles sergenti (Theobald) a potential malaria vector in Egypt.

Two immunoassays for malaria sporozoite detection and identification, the immunoradiometric assay (IRMA) and the enzyme-linked immunosorbent assay (ELISA) using the species-specific monoclonal antibodies are routinely performed in our laboratory. We analyzed (573) anopheline mosquitoes of A. sergenti (463), A. pharoensis (81) and A. multicolor (29) collected from Siwa-oases and Faiyum Governorate (two known active malaria foci in Egypt), for detection of P. falciparum and P. vivax sporozoites. P. falciparum sporozoites were detected by both IRMA and ELISA tests in two A. sergenti mosquitoes (one from Siwa 1/389 = (0.26%) and one from Faiyum Governorate 1/74 = (1.35%)). No P. vivax sporozoites were detected. This finding is important in explaining the malaria transmission and provide first incrimination of An. sergenti as the responsible vector of malaria in Siwa-oasis, Egypt.

Immunosuppressive medication associated with leishmanial antibodies in adults residing in an endemic focus of infantile visceral leishmaniasis--a case/control study.

In a focus of infantile visceral leishmaniasis in Al Agamy (Alexandria), Egypt, adults were found by radioimmune assay to have leishmanial antibodies. This finding was unexpected, and an explanation was sought. Seropositive adults and age- and sex-matched seronegative controls were interviewed to ascertain possible predisposing risk factors. Ten of 16 seropositive individuals were taking corticosteroids compared to one of 22 seronegative individuals (P = 0.0002). Two seropositive individuals (one woman and one man) were taking phenylbutazone, and two women were taking female sex hormones. The association between immunosuppressive medication and leishmanial seropositivity suggests that acquired changes in host population immunocompetence may significantly alter age-specific seroprevalence of leishmanial antibodies.

Natural infections of Leishmania major in domestic dogs from Alexandria, Egypt.

Two leishmanial isolates from dogs from Alexandria, Egypt, were typed serologically and biochemically as Leishmania major. This is the second time that L. major has been shown to occur in dogs. The significance of these findings as a misleading phenomenon in relation to the relatively recent outbreak of infantile kala-azar in the area of Alexandria is discussed.