Thrombus Aspiration Plus Intracoronary Abciximab vs Intracoronary Abciximab Alone in Patients with STEMI Undergoing Primary PCI

Background: Thrombus embolization during the Percutaneous Coronary Intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) is common and results in suboptimal myocardial perfusion and increased infarct size. Two strategies proposed to reduce distal embolization and improve outcomes after primary PCI is bolus intracoronary Abciximab and manual aspiration thrombectomy. There are several factors which influence the decision of primary PCI in a patient with AMI in developing countries. Cost of therapy and affordability is probably the most important factor. The additional cost for thrombus aspiration needs to be considered against the additional advantages in terms of better clinical outcome. Objectives: To compare the use of a combination of intracoronary Abciximab with manual thrombus aspiration to intracoronary Abciximab alone, in patients with STEMI undergoing primary PCI. Patients and Methods: This is a prospective observational study of patients with STEMI who underwent primary PCI between June 2018 to May 2019. A pre-approved study protocol was designed to determine the eligibility of STEMI patients to be included in the study. Patients with The patients have analysed in two groups: 84 patients received a combination of intracoronary Abciximab with manual thrombus aspiration & 80 patients received intracoronary Abciximab alone. The primary endpoint was the assessment of myocardial perfusion parameters namely Myocardial Blush Grade (MBG) in the culprit vessel & ST-segment resolution of >70% on ECG at 90 min after PCI. Secondary endpoints were the improvement in LV ejection fraction, cardiovascular mortality & recurrent MI at one-month post-procedure. Results: Result of the 84 patients who received combination of intracoronary Abciximab with manual thrombus aspiration, the primary endpoints namely the myocardial blush grade (MBG) of 2/3 was achieved in 72 patients (90.74%) & ST-segment resolution of >70% at 90 min was seen in 66 patients (78.57%) (p<0.001). Of the 80 patients who received only intracoronary Abciximab without thrombus aspiration, MBG 2/3 was achieved in 38 patients (47.5%) & ST-segment resolution of >70% at 90 min was seen in 28 patients (35%). At one month of follow up the secondary endpoints namely the LVEF in the combination group improved from 43.42±3.73 to 47.88±4.16% (p=0.12)and in the Abciximab group improved from 44.78±3.34 to 46.20±3.63%. Recurrent MI was seen in one patient in the combination group (p<0.001) & two patients in the ic Abciximab group. There was no cardiovascular mortality noted in the present study (p<0.001). Conclusion: Intracoronary Abciximab + manual thrombus aspiration reduces thrombus burden with better results in microvascular perfusion assessed by ST-segment resolution of >70% at 90 min & higher Myocardial Blush Grade compared to intracoronary Abciximab alone in patients with STEMI undergoing primary PCI.

Efficacy of pirimiphos-methyl (50% EC), as a larvicide for the control of Culex quinquefasciatus.

Background & objectives: Pirimiphos-methyl, an organophosphorus insecticide is known to overcome resistance mechanisms of mosquitoes to other organophosphates. Information on the duration of efficacy of pirimiphos-methyl (50% emulsifiable concentrate) for the control of immatures of Culex quinquefasciatus, the vector of bancroftian filariasis, is scanty and hence site specific field trials are necessary to determine the field dosage. Pirimiphos-methyl (50% EC) was tested for its efficacy in cesspits and drains against the immatures of Cx. quinquefasciatus at Puducherry, an endemic area for filariasis, south India. Methods: In cesspits, Pirimiphos-methyl (50% EC) was tested at the dosage of 25, 50, 100 and 200 g(ai)/ ha and in drains at 50, 100 and 200 g(ai)/ha. Immature density during pre-treatment and post-treatment periods was recorded and the efficacy was determined by calculating percentage reduction in larval and pupal densities for a period of about one month. Results: In cesspits, application of the insecticide at 25 and 50 g(ai)/ha reduced the density of larvae by >80 per cent for 2-4 days only, whereas at 100 and 200 g(ai)/ha, the efficacy lasted for 7-8 days. More than 80 per cent reduction was observed in pupal density for 4 days at 50 g(ai)/ha and for 10-12 days at 100 and 200 g(ai)/ha respectively. In drains treated with 50 g (ai)/ha, >80 per cent reduction in larval density was recorded up to 3rd day post-treatment. The efficacy showing >80 per cent reduction in larval density lasted for 12-13 days and the same in pupal density lasted for 10-12 days at 100 and 200 g(ai)/ha. Interpretation & conclusions: At the dosages of 100 and 200 g(ai)/ha, pirimiphos-methyl (50% EC) showed no difference in the control of larvae of Cx. quinquefasciatus in cesspits and drains. Pirimiphosmethyl may be applied at the field dosage of 100 g (ai)/ha at 10 day-intervals in the larval habitats of Cx. quinquefasciatus to achieve >80 per cent reduction in immature density.

Current status of filariasis in Chavakad taluk, Trichur district, Kerala.

A sample survey using parasitological, clinical and entomological indicators was carried out in all the 18 administrative units of Chavakad taluk, Trichur district, Kerala, India to assess the current filariasis situation. Cluster sampling procedure was followed to screen individuals. Both Wuchereria bancrofti and Brugia malayi species were found to be prevalent in this taluk. Microfilaria (mf) carriers with W. bancrofti were detected in eight areas while B. malayi was recorded only from one area. The two species were found to co-exist in another area. The highest infection rate registered for W. bancrofti was 1.51 while it was 0.3 for B. malayi. Infection due to W. bancrofti constituted 87.88% of the total 33 microfilaria cases. Prevalence of B. malayi was very low. Cases with clinical manifestation of filariasis were recorded in all the four areas surveyed. The present trend in the prevalence of infection (mf) and disease showed a decline in both the species when compared to earlier surveys of 1960s. At least 11 areas are still endemic for filariasis in this taluk. Although prevalence of mf was recorded for the first time in one of the areas viz., Elavalli, the rate was only 0.16%. Entomological surveys revealed the presence of 14 mosquito species, of which Culex quinquefasciatus contributed 84.85% and Mansonia 0.77%. While C. quinquefasciatus was recorded in all the 18 areas, Mansonia spp were found only in 8 areas. Only C. quinquefasciatus was found to harbour different developmental stages of W. bancrofti, with overall infection and infectivity rates of 1.94 and 0.97 respectively. The possible reason for the decline in vector density and infection in man are postulated.

Field evaluation of biodegradable controlled release formulation of fenthion against Mansonia mosquitos.

Controlled release monolithic formulation of fenthion, an organophosphorus mosquito larvicide, prepared by the physical entrapment of the active agent into biodegradable polymer matrices was evaluated against Mansonia mosquito larvae breeding in hydrophytes infested coconut husk retting ponds. Field evaluation was carried out at two application rates viz, 2.5 and 1.0 ppm. Absolute control of larval breeding was observed for 25 and 17 weeks and over 50% reduction in breeding density was observed for another 3 and 2 weeks for the respective application rates of 2.5 and 1.0 ppm. The bioassay carried out with the water samples collected from the ponds treated at 2.5 ppm against the fourth instar larvae of Mansonia annulifera showed larval mortality of more than 95% for 14 weeks and 80-95% from 15 to 25th week. The concentration of fenthion in the treated ponds was found to vary between 0.006 and 0.095 ppm during the evaluation period.

Aquatic vegetation and their natural hospitability to the immatures of Mansonia mosquitos, the vectors of Brugia malayi in Shertallai, Kerala, India.

Prevalence of various aquatic vegetation and their role in supporting vector breeding were studied by drawing plant samples from natural fresh water habitats in Shertallai region which is endemic for Brugia malayi. As many as 30 aquatic plant species were identified in addition to the most abundant and preferred host plants such as Pistia stratiotes, Salvinia molesta and Eichhornia crassipes which are of major concern due to their contribution for vector proliferation. Fallow lands and paddy fields recorded relatively a higher number of plant species. Natural breeding of Mansonia, the vector mosquitos was observed in 16 of them. Using the data on the prevalence, proportion of samples positive for Mansonia breeding and immature density, two indices viz, natural hospitability Index (NH) and Mansonia host plant Index (MHI) were developed for each plant species. Ranking of these plants in relation to Mansonia breeding was done based on these indices. Monochoria vaginalis has been identified to be one of the most important auxiliary host plant. Three grasses viz, Hygrorhiza aristata, Sacciolepis interrupta and Leersia hexandra were found to support all the three species of Mansonia viz, Ma. annulifera, Ma. uniformis and Ma. indiana with considerable immature density. The inclusion of these plants for weed/vector control is emphasized.

Effectiveness of slow release formulations of fenthion (Baytex) in the control of Mansonia breeding in polluted pond habitats.

Effectiveness of two types of granular formulations of fenthion (Baytex) was evaluated in controlling the breeding of Mansonia mosquitos in polluted pond habitats. Calcium carbonate and sand granular formulations, when applied at 2.50 g/m2 surface area with an average depth of 0.5 m were found to be effective in keeping the habitats completely free from Mansonia breeding for 14 days and 18 days respectively. Release of insecticide was slow and the effective duration of control after a single application was relatively longer in the sand formulation when compared to the calcium carbonate formulation. Single application of calcium carbonate and sand granular formulations of fenthion could effectively prevent Mansonia adult emergence for 23 and 30 days, respectively in polluted pond habitats, without causing any adverse effect on non-target insects.

Isolation of mosquito-pathogenic Bacillus sphaericus & B. thuringiensis from the root surface of hydrophytes.

Attempts were made to isolate B. sphaericus and B. thuringiensis active against mosquito larvae from the root surface of hydrophytes. Out of 139 samples processed, 86 B. sphaericus and 23 B. thuringiensis isolates were obtained. Sixty two of the B. sphaericus isolates belonged to the serotype H5a5b, 2 to H6 and 22 isolates did not agglutinate with any of the 6 antisera tested. Twenty of the B. thuringiensis isolates belonged to the H14 serotype, 1 each to the H10 and H17 serotype(s) and 1 to an unknown serotype. Fifty nine of the B. sphaericus and 20 of the B. thuringiensis isolates fall under highly toxic category with the LC50 dose of 1-50 ng/ml for Culex quinquefasciatus third instar larvae.

Attachment behaviour of immatures of Mansonia annulifera (Theobald), 1901.

The detachment and reattachment of the immatures of M. annulifera with their host plants (hydrophytes) is a regular phenomenon. This occurs frequently with the same plant, or with a different one, throughout the larval span. The duration between detachment and reattachment varied from 30 sec to one hour and majority of them get reattached within a minute. This behaviour is instinctive and not found to be influenced by food availability. In the absence of hydrophyte, early immature stages survive relatively longer (192 h), when compared to the late ones.