Perioperative Risk Factors for Persistent Postsurgical Pain After Inguinal Hernia Repair: Systematic Review and Meta-Analysis

Persistent postsurgical pain (PPSP) is one of the most bothersome and disabling long-term complications after inguinal hernia repair surgery. Understanding perioperative risk factors that contribute to PPSP can help identify high-risk patients and develop risk-mitigation approaches. The objective of this study was to systematically review and meta-analyze risk factors that contribute to PPSP after inguinal hernia repair. The literature search resulted in 303 papers included in this review, 140 of which were used for meta-analyses. Our results suggest that younger age, female sex, preoperative pain, recurrent hernia, postoperative complications, and postoperative pain are associated with a higher risk of PPSP. Laparoscopic techniques reduce the PPSP occurrence compared to anterior techniques such as Lichtenstein repair, and tissue-suture techniques such as Shouldice repair. The use of fibrin glue for mesh fixation was consistently associated with lower PPSP rates compared to tacks, staples, and sutures. Considerable variability was observed with PPSP assessment and reporting methodology in terms of study design, follow-up timing, clarity of pain definition, as well as pain intensity or interference threshold. High or moderate risk of bias in at least one domain was noted in >75% of studies. These may limit the generalizability of our results. Future studies should assess and report comprehensive preoperative and perioperative risk factors for PPSP adjusted for confounding factors, and develop risk-prediction models to drive stratified PPSP-mitigation trials and personalized clinical decision-making. PERSPECTIVE: This systematic review and meta-analysis summarizes the current evidence on risk factors for persistent pain after inguinal hernia repair. The findings can help identify patients at risk and test personalized risk-mitigation approaches to prevent pain. PROSPERO REGISTRATION: htttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=154663.

Methadone pharmacogenetics in vitro and in vivo: Metabolism by CYP2B6 polymorphic variants and genetic variability in paediatric disposition

AIMS

Methadone metabolism and clearance are determined principally by polymorphic cytochrome P4502B6 (CYP2B6). Some CYP2B6 allelic variants affect methadone metabolism in vitro and disposition in vivo. We assessed methadone metabolism by CYP2B6 minor variants in vitro. We also assessed the influence of CYP2B6 variants, and P450 oxidoreductase (POR) and CYP2C19 variants, on methadone clearance in surgical patients in vivo.

METHODS

CYP2B6 and P450 oxidoreductase variants were coexpressed with cytochrome b5 . The metabolism of methadone racemate and enantiomers was measured at therapeutic concentrations and intrinsic clearances were determined. Adolescents receiving methadone for surgery were genotyped for CYP2B6, CYP2C19 and POR, and methadone clearance and metabolite formation clearance were determined.

RESULTS

In vitro, CYP2B6.4 was more active than wild-type CYP2B6.1. CYPs 2B6.5, 2B6.6, 2B6.7, 2B6.9, 2B6.17, 2B6.19 and 2B6.26 were less active. CYPs 2B6.16 and 2B6.18 were inactive. CYP2B6.1 expressed with POR variants POR.28, POR.5 and P228L had lower rates of methadone metabolism than wild-type reductase. In vivo, methadone clinical clearance decreased linearly with the number of CYP2B6 slow metabolizer alleles, but was not different in CYP2C19 slow or rapid metabolizer phenotypes, or in carriers of the POR*28 allele.

CONCLUSIONS

Several CYP2B6 and POR variants were slow metabolizers of methadone in vitro. Polymorphisms in CYP2B6, but not CYP2C19 or P450 reductase, affected methadone clearance in vivo. CYP2B6 polymorphisms 516G>T and 983T>C code for canonical loss of function variants and should be assessed when considering genetic influences on clinical methadone disposition. These complementary translational in vitro and in vivo results inform on pharmacogenetic variability affecting methadone disposition in patients.

Effect of discontinuation of ticagrelor and switching-over to other P2Y12 agents in patients with acute coronary syndrome: a single-center real-world experience from India

Background

Dual antiplatelet therapy is the current standard of care after acute coronary syndrome (ACS) and percutaneous coronary intervention (PCI). We intended to study the pattern of use of ticagrelor in patients with acute coronary syndrome undergoing PCI and the effect of switching over to other P2Y12 receptor inhibition on clinical outcomes.

Results

All patients aged > 18 years who had been admitted with acute coronary syndrome and had been provided ticagrelor as the second antiplatelet agent were included as study participants. The primary outcome of the study was the composite outcome of death, recurrent myocardial infarctions, re-intervention, and major bleeding.

We studied 321 patients (54 female patients, 16.82%). The mean age of the patients was 56.65 ± 11.01 years. Ticagrelor was stopped in 76.7% on follow-up. It was stopped in 6.3%, 13.5%, 13.1%, 21.9%, and 45.1% of patients during the first month but after discharge, between first and third months, between 3 and 6 months, between 6 and 12 months, and after 12 months, respectively. In the majority of patients, ticagrelor was replaced by clopidogrel (97.9%). It was stopped according to the physician’s discretion in 79.3% of patients, whereas it was the cost of the drug that made the patient to get swapped to another agent in 18.6%. No difference in the primary composite outcome was observed between the groups where ticagrelor was continued post 12 months and ticagrelor was continued and ticagrelor was switched-over to another agent. Similarly, no difference in death, recurrent myocardial infarctions, re-interventions, or major bleeding manifestations was observed between the two groups.

Conclusion

In patients with acute coronary syndrome who undergo PCI, we observed that early discontinuation of ticagrelor and switching over to other P2Y12 inhibitors after discharge did not affect clinical outcomes.

Analytical study of Kuberaksha/Kantaki Karanja Patra Churna [Caesalpinia Bonduc (L.) Roxb. leaf powder]

Caesalpinia bonduc (L.) Roxb. (Kuberaksha) is an Ayurvedic herb used in the management of malaria, liver disorders, worms, edematous conditions, etc. Based on classical Ayurvedic textual indications and recent pharmacological studies, its leaf powder was selected for studying its effect clinically on filaria. Before conducting the clinical trails, this leaf powder was subjected to certain chemical studies to find the pH, ash value, extractive values, High Performance Thin Layer Chromatography (HPTLC), etc. for standardization of the drug.

Polysaccharide-free nucleic acids and proteins of Abelmoschus esculentus for versatile molecular studies

Abelmoschus esculentus (okra) is one of the polysaccharide rich crop plants. The polysaccharides interfere with nucleic acids and protein isolation thereby affecting the downstream molecular analysis. So, to understand the molecular systematics of okra, high quality DNA, RNA and proteins are essential. In this study we present a method for extracting genomic DNA, RNA and proteins from polysaccharide rich okra tissues. The conventional extraction procedures were integrated with purification treatments with pectinase, RNase and proteinase K, which improved the quality and quantity of DNA as well. Using SDS, additional washes with CIA and NaCl precipitation improved the RNA isolation both quantitatively and qualitatively. Finally, ammonium acetate mediated protein precipitation and re-solubilization increased the quality of total protein extracts from the okra leaves. All of the methods above not only eliminated the impurities but also improved the quality and quantity of nucleic acids and proteins. Further, we subjected these samples to versatile downstream molecular analyses such as restriction endonuclease digestion, RAPD, Southern, reverse transcription-PCR and Western analysis and were proved to be successful.

Mycotoxin occurrence and Aspergillus flavus soil propagules in a corn and cotton glyphosate-resistant cropping systems

The effects of cotton-corn rotation and glyphosate use on levels of soil-borne Aspergillus flavus, aflatoxin and fumonisin contamination in corn and cotton seed were determined during 2002-2005 in Stoneville, Mississippi (USA). There were four rotation systems (continuous cotton, continuous corn, cotton-corn and corn-cotton) for both glyphosate-resistant (GR) and non-GR cultivars-herbicide system arranged in a randomized complete block design with four replications. Aspergillus flavus populations in surface (5-cm depth) soil, sampled before planting (March/April), mid-season June) and after harvest (September), ranged from 1.47 to 2.99 log (10) cfu g(-1) soil in the four rotation systems. Propagules of A. flavus were higher in the continuous corn system compared to the continuous cotton system on three sample dates, and cotton rotated with corn decreased A. flavus propagules in three of nine sample dates. Propagules of A. flavus were significantly greater in plots with GR cultivars compared to non-GR cultivars in three samples. In cotton seed, aflatoxin and fumonisin levels were similar (< or = 4 microg kg(-1) and non-detectable, respectively) regardless of rotation and glyphosate. In corn grain, aflatoxin was above the regulatory level (> or = 20 microg kg(-1)) only in GR cultivar in 2004 and 2005. Fumonisin was higher in non-GR cultivar (4 mg kg(-1)) regardless of rotation in 2004; however, in 2002, 2003 and 2005, aflatoxin and fumonisin levels were similar regardless of rotation and glyphosate. These results indicate the potential for increased aflatoxin and fumonisin levels (1 of 4 years) in corn; however, climatic conditions encountered during this study did not allow for mycotoxin production. In laboratory incubation studies, fairly high concentrations of glyphosate were required to inhibit A. flavus growth; however no short-term effect of soil treatment with glyphosate on A. flavus populations were observed. These data suggest that altered populations of A. flavus or higher aflatoxin concentrations in corn grain were due to indirect effects of the GR cropping system.

Prediabetes and hypertension

Prediabetes occurs due to two basic defects--insulin resistance and/or beta-cell failure. An observation suggested that insulin resistance may be associated with essential hypertension. There are some thoughts to favour the argument that insulin resistant Individuals are at a higher risk to develop hypertension as compared to insulin sensitive individuals. Some pathophysiological causes which have been commonly observed and hypothesised are narrated in this article. Management of hypertension in prediabetes should include antihypertensives and therapeutic lifestyle modification. To manage hypertension in prediabetes one should think for dietary modification, reduced salt intake, physical activity, smoking cessation, use of statins and antihypertensives.

Biodegradable-polymer-based, paclitaxel-eluting Infinnium stent: 9-Month clinical and angiographic follow-up results from the SIMPLE II prospective multi-centre registry study

BACKGROUND

SIMPLE II was a multi-centre, prospective registry study aimed at investigating the safety and efficacy of the Infinnium (Sahajanand Medical Technologies Pvt. Ltd, India) paclitaxel-eluting stent for the treatment of single de novo lesions in the native coronary arteries.

METHODS

One hundred and three patients with symptomatic coronary artery disease were treated for single de novo native coronary artery lesions using the Infinnium stent (paclitaxel concentration 1.4 mcg/mm2 released over 48 days) in a multi-centre, prospective study performed on 3 continents (Asia, Europe and South America). The primary safety endpoint was major adverse cardiac events at 30 days (MACE 30d) and efficacy was assessed by in-stent binary restenosis as measured by quantitative coronary angiography (QCA) at six-month follow-up. A clinical follow-up was scheduled at nine months.

RESULTS

The mean patient age was 58.5 years; 70.9% were males; 43.7% had unstable angina and 38.8% previous myocardial infarction. Risk factors included hypertension in 62.1%, hypercholesterolemia in 52.4%, current smoking in 32.0% and diabetes in 28.2%. Stent implantation was successful in all patients, with more than one stent being implanted in 9 patients (8.7%). Hierarchical MACE 30d was 2.9%. At nine months, 101 patients had clinical follow-up (1 patient had died and 1 refused). There was one death (1.0%), one Q-wave myocardial infarction (Q MI) (1.0%), three non-Q MIs (2.9%), one clinically-driven target lesion Coronary Artery Bypass Grafting (CABG) (1.0%), and one clinically-driven target lesion repeat percutaneous coronary intervention (re-PCI) (1.0%). The overall event-free rate at nine months was 93.2%. QCA revealed in-stent and in-segment late loss of 0.38+/-0.49 mm and 0.18+/-0.46 mm, resulting in binary restenosis rates of 7.3% and 8.3%, respectively. There was one case of late stent thrombosis in the patient experiencing the Q MI and subsequent re-PCI.

CONCLUSIONS

The Infinnium paclitaxel-eluting stent appears to be safe and efficacious for the treatment of single de novo lesions in coronary arteries in a patient population with symptomatic coronary artery disease (CAD).

Prevalence of renovascular abnormality in patients undergoing cardiac catheterization

OBJECTIVE

To determine the prevalence of renal artery disease and to correlate the underlying risk factors like age, sex, diabetes, hypertension, urea and creatinine in patients who have undergone angiogram for cardiovascular diseases.

METHODS

Retrospective analysis of the reports of angiogram of patients who have undergone cardiac catheterization in Vijaya Heart Foundation for cardiovascular diseases.

RESULTS

The prevalence of renovascular stenosis is 12.4%. Prevalence of hypertension and diabetes in the group of patients with renovascular stenosis compared with group having coronary artery disease is not statistically significant (p > 0.8). Univariate and multivariate logistic identified age, diabetes, hypertension and urea as independent predicators of renal artery stenosis; while variables like sex and serum creatinine were not associated.

CONCLUSION

High prevalence of unsuspected renovascular abnormalities is found in patients who undergo angiography for cardiovascular disease. Factors like age, diabetes, hypertension and urea could be clinical predicators of renal artery stenosis. Hence renal arteries should be visualized routinely in patients undergoing coronary angiogram for cardiovascular disease.

Euglycemic and hypolipidemic activity of PAT5A: a unique thiazolidinedione with weak peroxisome proliferator activated receptor gamma activity

The euglycemic and hypolipidemic activities of PAT5A, a novel pyridine analog of thiazolidinedione, have been evaluated in different animal models. Administration of PAT5A to db/db mice resulted in dose-dependent decreases in plasma glucose, triglyceride, and insulin levels, and an improved glucose tolerance. The glucose-lowering activity of PAT5A was better than that of troglitazone and comparable to that of rosiglitazone. In addition, PAT5A showed better lipid-lowering activity than troglitazone or rosiglitazone. A similar profile was seen in ob/ob mice. In high-fat-fed Sprague Dawley rats, PAT5A treatment reduced plasma triglyceride and total cholesterol levels. An in vitro peroxisome proliferator activated receptor gamma (PPARgamma) transactivation assay in HEK-293 cells showed poor transactivation for PAT5A compared with rosiglitazone. PAT5A did not show any PPARalpha- or PPARdelta-activating properties. Ex vivo study in db/db mice treated with PAT5A showed decreased activity of liver glucose 6-phosphatase, a key enzyme in gluconeogenesis. A 28-day probe toxicity study in Wistar rats did not show any treatment-related alterations in hematologic and biochemical parameters, nor any macroscopic and microscopic changes in the vital organs, whereas rosiglitazone treatment increased liver and heart weights. Our results indicate that PAT5A is a potent insulin sensitizer and hypolipidemic compound with a weak PPARgamma activation potential. Both in vivo and in vitro results suggest that PAT5A improves glucose kinetics and lipid levels through mechanisms not related to PPAR activation.

Periodic intermittent electromechanical dissociation: hemodynamic correlate of a malfunctioning mechanical prosthetic valve

We describe a patient who developed the unusual haemodynamic phenomenon of periodic intermittent electromechanical dissociation during regular sinus tachycardia about 20 hours after mitral valve replacement with a tilting disc mechanical prosthesis. Echocardiographic confirmation allowed prompt and life saving corrective surgery for a stuck prosthetic valve disc.

Fatty acid profile and the atherogenic risk in fish consuming and non fish consuming people

Epidemiological studies have indicated a lower incidence of cardiovascular disease in populations with a high habitual intake of marine fish and fish oils, and this apparent protection may be due to the presence of n-3 fatty acids in the dietary fish. Two populations, a rish consuming one from coastal area and an inland one with non fish consuming from Nellore district or South India were selected for the present study. A total of one thousand healthy subjects were randomly chosen (500 in each population) from both sexes, aged from 20 to 70 years. The concentration of serum cholesterol, triacylglycerol and LDL-cholesterol were significantly lower in fish consumers, whereas HDL-cholesterol was higher in fish consumers than in non fish consumers. The difference between the percent quantities of the three n-3 fatty acids (eicosapentaenoic, docosapentaenoic and docosahexaenoic acids) was highly significant (p < 0.001) with a greater value in fish consumers.

Pseudoaneurysm of the ascending aorta complicating cardiac surgery: role of echocardiography in the diagnosis

Pseudoaneurysms of the ascending aorta is a rare postoperative complication which, once identified, needs urgent attention. This report describes 5 consecutive patients with this complication who presented 2-15 months following open heart surgery. The role of cross-sectional echocardiography in diagnosis of this condition is highlighted.

Ventricular septal defect with aortic regurgitation: a hemodynamic and angiographic profile in Indian subjects

The records of 362 patients of Ventricular Septal Defect (VSD) were analysed to find out the incidence of aortic regurgitation (AR) and their hemodynamic and angiographic features. Thirty-seven patients (10.2%) were found to have AR, whose mean age was 13.4 years (range: 2-45) and male to female ratio was 5:1. Of the 37 cases 31 (84%) had infracristal and 6 (16%) had supracristal VSD. In 31 patients with infracristal VSD the prolapsing cusp was Right Coronary Cusp (RCC) in 14 (48%), Noncoronary Cusp (NCC) in 12 (41%) and both RCC and NCC in 3 (11%). Of the 6 patients with supracristal VSD the prolapsing cusp was RCC in 5 (83%) and NCC in 1 (17%). In two patients the AR was due to bicuspid aortic valve. The pulmonary artery pressure was normal in 26 of 37 (70.2%) patients and the left to right shunt was 1.5:1 or less in 23 of 37 (62%) patients. Nineteen of the 37 patients (51.3%) had grade I or II AR and the remaining 18 (48.7%) had grade III or IV AR. There was no relationship between the severity of AR and the location of the VSD. In conclusion, in this series, the incidence of VSD+AR is relatively higher and that of supracristal VSD is lower. In majority of patients the left to right shunt is small and pulmonary artery pressure within normal limits. The prolapse of RCC is more common in supracristal VSD and there is no relation between the severity of AR and the location of the VSD.

Correlation of 12 lead ECG QRS score with severity of aortic stenosis

The hemodynamic data and electrocardiograms of thirty-three patients of moderate to severe aortic stenosis were analysed retrospectively to find out if there was any correlation between 12 lead ECG-QRS score and left ventricular peak systolic pressure (LVPSP) and/or peak systolic gradient (PSG) across the aortic valve. The mean age of the study population was 33.33 (+/- 15.02SD) years, with the male to female ratio being 9:2. The mean 12 lead ECG-QRS score in these 33 patients was 281 mm (+/- 46.02SD), the mean LVPSP 203.52 mmHg (+/- 46.62SD) and the mean PSG across the aortic valve was 81.0 mmHg (+/- 41.62SD). There was good correlation of 12 lead ECG-QRS score with LVPSP (r = 0.47, P less than 0.001) and with PSG across the aortic valve (r = 0.58, P less than 0.001), latter being more significant. The best correlation was however found between 12 lead ECG-QRS score and PSG across the aortic valve in patients over 35 years of age (r = 0.88). In conclusion there is a direct relationship between 12 lead ECG-QRS score and peak systolic gradient across the aortic valve and the latter can be approximately calculated non-invasively with the help of regression equation- Peak systolic gradient (in mmHg) = 12 lead ECG-QRS score/3 - 10.6

Myocardial bridge (MB): an angiographic curiosity?

The coronary angiograms of 1,500 cases performed between 1981 and 1989 were analysed to find out the incidence of Myocardial Bridge (MB) and its significance as regards myocardial ischemia. Sixteen of these (1.06%) were found to have MB. Their ages ranged from 27-70 years (m = 49.2) and male:female ratio was 13:3. Out of 16 patients, 7 (group A) had associated coronary artery disease (CAD) (7 of 1421; 0.49%) and remaining 9 (group B) had no associated CAD (9 of 79; 11.39%). All the MB were found on left anterior descending artery (LAD) (3 on proximal LAD and 13 on mid LAD). No MB was found on right coronary artery (RCA) or circumflex arteries. The location of the MB did not affect the pattern of CAD. Chronic stable angina was the commonest presenting symptom in group A patients (5 out of 7) and atypical angina in group B patients (5 out of 9). Majority of group B patients had either normal or nonspecific ST-T changes in ECG (7 out of 9). However, the presence of previous myocardial infarction or ECG evidence of 'Q' wave infarction (2 out of 2) was always associated with significant CAD. Similarly, regional wall motion abnormalities on echocardiogram were always found in patients with significant CAD and old myocardial infarction. All 9 patients with MB and normal coronary arteries were managed conservatively with good relief of symptoms, whereas other seven patients were managed on the merits of the underlying CAD. In conclusion, the MB is a normal variant found incidentally on coronary angiography, and does not have any definite clinical correlations or pathological significance.

Tetralogy of Fallot with hypertrophic cardiomyopathy--an unknown combination

A hitherto unknown association of Tetralogy of Fallot (TF) and Hypertrophic Cardiomyopathy (HCM) diagnosed by two dimensional echocardiography, cardiac catheterization and angiocardiography is reported. Patient underwent emergency aortopulmonary shunt successfully. The literature is reviewed in brief.

Mean frontal QRS axis and pulmonary artery pressures in rheumatic mitral stenosis

The relationship between the mean frontal QRS axis calculated from the scalar 12 lead ECG, and the pulmonary artery (PA) pressures obtained by cardiac catheterisation in 64 cases of isolated rheumatic mitral stenosis (MS), was analysed. An overall trend of rightward axis shift with increasing PA pressures was observed; the best correlation was seen with systolic PA pressures (r = 0.51). It was possible to recognise 3 categories of patients: (1) With an axis of 70 degrees and below, systolic PA pressures were below 70 mm Hg in 82.4% of cases and below 80 mm Hg in 94% of cases; diastolic pressures were below 40 mm Hg in 88.2%; mean PA pressures were below 50 mm Hg in 88.2% cases. (2) With an axis of 71 degrees to 100 degrees, systolic PA pressures ranged from 30 to 120 mm Hg, diastolic PA pressures from 12 to 60 mm Hg and mean PA pressures from 19 to 80 mm Hg. (3) With an axis of above 100 degrees, systolic PA pressures were over 70 mm Hg in 95.5% of cases, diastolic PA pressures more than 30 mm Hg in 90.9%, and mean PA pressures more than 45 mm Hg in 90.9% cases. It was therefore possible to predict, with reasonable accuracy, the range of PA pressures in patients with isolated MS, except in those cases with an axis between 71 and 100 degrees.

New approach to curb the transmission of leprosy

The effect of local treatment of nose of lepromatous type of patients with different formulations of rifampicin nasal drops/sprays was investigated in a large number of patients. The preparations were either sprayed or instilled into the nostrils after flushing the nostrils with normal saline at 37 degrees C. It was observed that 10 mg/ml of rifampicin was effective in reducing the BI and MI to zero in nose in seven days in majority of the patients. No untoward effect was seen in any of the patients. It is suggested that nasal sprays/drops may be able to prevent the transmission of hanseniasis, as nose is recognised to be an important portal of exit of M. leprae. Further when rifampicin drops/sprays are used as soon as the diagnosis is made, the nasal deformity may be prevented. It is believed that local treatment along with systemic therapy would go a long way in controlling the transmission of hanseniasis.

Severe syphilitic aortic regurgitation with bilateral critical coronary ostial stenosis

A forty-year-old male with syphilitic severe aortic regurgitation and critical bilateral coronary ostial stenosis, proved by cardiac catheterization and angiocardiography, is presented. He underwent successful aortic valve replacement and coronary artery bypass grafting with gratifying results.

Subaortic stenosis associated with anomalous right ventricular muscle bundle and ventricular septal defect

A rare case of biventricular outflow tract obstruction in the form of discrete subaortic membrane and hypertrophic anomalous right ventricular muscle bundle associated with ventricular septal defect is presented.

Detection of silent myocardial ischemia by Holter monitoring and its relation to severity of coronary artery disease

Thirty-five patients of chronic stable angina, unstable angina and post MI angina, who were on medical treatment, underwent 24 hours Holter monitoring and coronary angiography to find out the incidence of Silent Myocardial Ischemia (SMI) and its relation to anatomic severity of coronary artery disease. Total duration of Holter monitoring was 835.32 hours (average 23.40 hours per patient) with 48 ischemic episodes out of which 16 were painful and 32 painless. Total duration of painful episodes was 189 minutes and that of painless episodes was 428 minutes (70% was constituted by SMI). Out of 35 patients, 6 (17.14%) had SMI; 2 of 17 (11.7%) of chronic stable angina, 2 of 8 (25%) of unstable angina, and 2 of 10 (20%) of post-infarction angina patients. On analysis of coronary angiogram, all 6 (100%) patients with SMI, and only 22 out of 29 (76%) without SMI, had severe multiple coronary artery disease. Thus, although the overall incidence of SMI in this series is low, its presence invariably indicates a severe degree of coronary artery disease.

Results of 130 consecutive percutaneous transluminal coronary angioplasty (PTCA) procedures in single and multiple vessel coronary artery disease (CAD)

Over the last 1-year period, we performed 130 consecutive percutaneous transluminal coronary angioplasty (PTCA) procedures in 108 patients, 103 of them were males and 5 females. Their mean age was 50.9 +/- 6.83 years (range 33-70). All of them were symptomatic, manifested by acute infarction in 18 (17%), chronic stable angina in 30 (28%), unstable angina in 5 (5%) and post-myocardial infarction angina in 55 (51%) cases. Among these patients, single-vessel CAD was present in 42 (39%), double-vessel in 37 (34%) and triple-vessel CAD in 11 (10%) patients. Nine patients (8.3%) had total occlusion, and 18 (16.6%) had tandem or bifurcation lesions of target artery. Of the 112 PTCA procedures (excluding those in acute infarction), 53 (47%) were performed on LAD, 29 (26%) on RCA, and 30 (27%) on circumflex artery, with success rates of 86.7%, 83.3% and 82.7% respectively. The overall success rate was 85% (95 of 112). The PTCA was successful in 36 of 42 (85.7%), 32 of 37 (86.5%) and 9 on 11 (82%) patients with single, double and triple-vessel CAD respectively. The mean diameter stenosis reduced from 67.1 +/- 16.54% to 19.9% +/- 10.9%. PTCA was unsuccessful in 17 (15%) due to failure to cross the lesion in 11 (9.7%), failure to dilate in 1 (0.9%) and abrupt reclosure of dilated segment in 5 (4.4%). Four (3.5%) patients underwent CABG. Two patients had redo PTCA owing to restenosis at about 6 months of first PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Subvalvular aneurysm. Two-dimensional echocardiographic features

A rare case of subvalvular aneurysm diagnosed by two-dimensional echocardiography and confirmed at cardiac catheterization is presented.

Streptokinase--biochemistry and clinical application

Plasminogen activation to plasmin is due to enzymatic cleavage of a single peptide bond in the zymogen molecule. Streptokinase is not an enzyme and its activation of plasminogen is indirect. Streptokinase forms stoichiometric complexes with plasmin and plasminogen and these complexes activate plasminogen to plasmin. Streptokinase is species selective in its action.

Ancrod enhances the thrombolytic effect of streptokinase and urokinase

Since thrombi continue to incorporate fibrin during lysis we tested the effect of pretreatment with ancrod, a defibrinating agent from Malaysian pit viper venom, on thrombolysis with urokinase and streptokinase. Thrombi were induced by copper-coils in the carotid arteries of the dogs, weighed after 1 hour and inserted into the femoral arteries of the same animals. They were then exposed for 15 min to iv boluses of streptokinase 10,000 U/kg, urokinase 10,000 U/kg and urokinase 25,000 U/kg with or without pretreatment with ancrod. Ancrod depleted fibrinogen within 5 min and enhanced the lytic effect of streptokinase from 25 +/- 8% to 59 +/- 13% (p less than .05), urokinase 10,000 U/kg from 16 +/- 11% to 66 +/- 18% (p less than .01) and urokinase 25,000 U/kg from 27 +/- 17% to 85 +/- 8% (p less than .001) of the initial thrombus weight. Ancrod itself did not activate plasminogen to plasmin. We conclude that ancrod enhances thrombolysis probably by depleting fibrinogen and preventing new fibrin incorporation into the thrombus during lysis.

Interaction of SK-human plasmin, SK-dog plasmin complexes with alpha 2-antiplasmin and alpha 2-macroglobulin

In patients treated with streptokinase there is a rapid and significant decrease in the level of fibrinogen in the circulation. In dogs given streptokinase there is no such change in circulating fibrinogen. To find an explanation for this species difference in response to streptokinase, the inhibition of SK-human plasmin and SK-dog plasmin by soybean trypsin inhibitor, alpha 2-antiplasmin and alpha2-macroglobulin were compared in this study. Soybean trypsin inhibitor completely blocked the hydrolysis of S-2251 substrate (D-val-L-leu-lys-p-nitroanilide) by SK-dog plasmin and had no effect on SK-human plasmin. Alpha 2-Antiplasmin, the physiologically important regulator of fibrinolysis, inhibited S-2251 hydrolysis by SK-dog plasmin but not the activity of SK-human plasmin. alpha 2-Macroglobulin showed 100% inhibition of proteolytic activity and 50% inhibition of S-2251 activity of SK-dog plasmin, and had no effect on SK-human plasmin. Studies with fresh human and dog plasma also showed that the SK-dog plasmin is rapidly inactivated by the alpha 2-antiplasmin present in the plasma. The inactivation of SK-dog plasmin and not SK-human plasmin by plasma inhibitors explains the differences in the response of dog and humans to the administration of streptokinase.

Kallikrein-like activity of crotalase, a snake venom enzyme that clots fibrinogen

During the amino acid sequence determination of crotalase (EC 3.4.21.30), the thrombin-like enzyme from the venom of Crotalus adamanteus (eastern diamondback rattlesnake), we found that, in addition to the expected structural homology with bovine thrombin (EC 3.4.21.5), there was even greater homology with porcine pancreatic kallikrein (EC 3.4.21.8). In exploring further the similarities between crotalase and kallikrein, several striking observations were made. First, crotalase was rapidly and specifically inhibited by the tripeptide affinity labeling derivative prolylphenylalanylarginine chloromethyl ketone, which is known to be a specific inhibitor of kallikrein. Second, NaDodSO4/acrylamide gel electrophoresis revealed that crotalase cleaves the plasma kallikrein-susceptible bonds in human high molecular weight kininogen, producing an intermediate with procoagulant activity. Crotalase-catalyzed cleavage of high molecular weight kininogen also liberates kinin as evidenced by rat blood pressure bioassay. Finally, crotalase exhibits substrate specificity not only for the thrombin chromogenic substrate S-2238 but also for the kallikrein substrates S-2302 and S-2266. Interestingly, one of the other reactions catalyzed by plasma kallikrein, the activation of plasminogen, was not one of the activities exhibited by crotalase.

Thrombin-like and fibrinolytic enzymes in the venoms from the Gaboon viper (Bitis gabonica), eastern cottonmouth moccasin (Agkistrodon p. piscivorus) and southern copperhead (Agkistrodon c. contortrix) snakes

Crude venom from B. gabonica contained weak fibrinogen clotting activity but no visible fibrinolytic activity, whereas venoms from A. p. piscivorus and A. c. contortrix exhibited fibrinolytic activity (by fibrin plate assay) but no thrombin-like activity. These snake venoms were fractionated on Sephadex G-100 with the following results. Thrombin-like activity in B. gabonica venom was eluted in a single protein peak with a molecular weight of 40,000. Agkistrodon p. piscivorus venom contained a single peak of fibrinolytic activity with a molecular weight of 34,000. Interestingly, venom from A. c. contortrix, which showed no thrombin-like activity in crude venom, contained both thrombin-like and fibrinolytic activities in fractions with molecular weights of 73,000 and 25,000 respectively. No plasminogen activation activity was observed in any of the crude venoms or venom fractions eluted from G-100. In view of the possible clinical potential of these enzymes as defibrinogenating or thrombolytic agents, it will be of great interest to further purify and characterize them.