Enhanced external counterpulsation as an adjunct to revascularization in unstable angina

Enhanced external counterpulsation (EECP) is an effective noninvasive treatment for chronic stable angina. Despite intensive risk factor modification, a patient required two surgical coronary revascularizations and seven multivessel angioplasties over a 26-month period, demonstrating recurrent unstable angina and persistent thallium perfusion defects despite revascularization. Post EECP, angina was relieved, thallium defects were resolved and the patient has remained asymptomatic for 36 months.

Maximizing the hemodynamic benefit of enhanced external counterpulsation

BACKGROUND

Enhanced external counterpulsation (EECP) has been demonstrated to be an effective treatment for angina and exertional ischemia in patients with coronary disease.

HYPOTHESIS

It is hypothesized that the ability of EECP to enhance the recruitment or development of coronary collaterals in coronary artery disease may be determined by the relative magnitude of diastolic augmentation (DA) and systolic unloading (SU). This study examines the relation between the proposed EECP effectiveness ratio (DA/SU), as assessed by finger plethysmography, and changes in descending aortic flow as assessed by Doppler echocardiography in 15 patients during EECP.

METHODS

Varying external cuff pressures (0-275 mmHg) were used to generate a range of DA/SU ratios. The effect on aortic antegrade systolic and retrograde diastolic flow was assessed by Doppler echocardiography to determine whether there was an optimal EECP effectiveness ratio that maximizes the hemodynamic effects of EECP. With increasing DA/SU there was an initial positive linear increase in both systolic and diastolic flow volume. Systolic flow maximized at an effectiveness ratio of 1.5 and diastolic flow at a ratio of 2.0

RESULT

Therefore, effectiveness ratios (DA/SU) in the range of 1.5-2.0 are optimal for maximizing the hemodynamic effects of EECP.

Prior revascularization increases the effectiveness of enhanced external counterpulsation

BACKGROUND AND HYPOTHESIS

Enhanced external counterpulsation (EECP) is an effective noninvasive treatment for chronic angina. However, its usefulness has been felt to be limited in patients with angiographically demonstrated triple-vessel coronary artery disease (CAD), in accord with the hypothesis that a patent vessel is necessary for transmission of the EECP-augmented coronary artery pressure and volume to the distal coronary vasculature.

METHODS

The effect of revascularization [coronary artery bypass grafting (CABG)] prior to EECP was examined in 60 patients with CAD and chronic angina (35 without and 25 with prior CABG). Patients were grouped by the extent of CAD (single-, double-, triple-vessel disease in the unrevascularized group) and by the extent of residual disease (number of stenotic native vessels unbypassed or supplied by a stenotic graft in the CABG group). Significant CAD or graft stenoses were defined as stenoses demonstrating > or = 70% luminal diameter narrowing. Benefit was assessed by improvement in post-EECP treatment over pretreatment radionuclide stress testing.

RESULTS

Radionuclide stress testing demonstrated a comparable favorable response (80 vs. 71%; p = NS) in patients with prior CABG versus unrevascularized patients. Enhanced external counterpulsation was highly and comparably effective in patients with unrevascularized native single- and double-vessel CAD and in patients with CABG with residual single- and double-vessel CAD (88 vs. 80%; p = NS). Most notably, CABG significantly increased the beneficial response to EECP in those patients with triple-vessel CAD and stenotic grafts compared with unrevascularized patients with triple-vessel CAD (80 vs. 22%; p < 0.05 by chi-square test).

CONCLUSION

The results suggest a new role for EECP as an effective treatment for post CABG ischemia, despite extensive CAD and even in the presence of stenotic grafts.

Seroepidemiology of low and high oncogenic risk types of human papillomavirus in a predominantly male cohort of STD clinic patients

Human papillomaviruses (HPV) infecting the genital tract are associated with warts and anogenital malignancies. Although HPV is a highly prevalent sexually transmitted disease (STD), the majority of research has focused on female cohorts due to gender specific sequelae. Our objective was to measure the epidemiological features and seroprevalences of HPV-6/11 and 16 in a predominantly male group of STD clinic patients. High-risk individuals (n=687), who attended the public STD clinic were administered a behavioural questionnaire and serum tested for antibodies against HPV-6/11 and HPV-16 capsids via capture enzyme-linked immunosorbent assay. Despite the male predominance in this study, women were significantly more likely to have antibodies against both HPV-6/11 and HPV-16. Condom use appeared to be partially protective against HPV-16 seropositivity only. In conclusion, despite exhibiting increased risk behaviour, men were less likely to be HPV seropositive. Additional studies utilizing male cohorts are warranted to further elucidate this phenomenon.

A premature termination codon in either exon of minute virus of mice P4 promoter-generated pre-mRNA can inhibit nuclear splicing of the intervening intron in an open reading frame-dependent manner

How premature translation termination codons (PTCs) mediate effects on nuclear RNA processing is unclear. Here we show that a PTC at nucleotide (nt) 385 in the NS1/2 shared exon of P4-generated pre-mRNAs of the autonomous parvovirus minute virus of mice caused a decrease in the accumulated levels of doubly spliced R2 relative to singly spliced R1, although the total accumulated levels of R1 plus R2 remained the same. The effect of this PTC was evident within nuclear RNA, was mediated by a PTC and not a missense transversion mutation at this position, and could be suppressed by improvement of the large intron splice sites and by mutation of the AUG that initiated translation of R1 and R2. In contrast to the PTC at nt 385, the reading frame-dependent effect of the PTC at nt 2018 depended neither on the initiating AUG nor the normal termination codon for NS2; however, it could be suppressed by a single nucleotide deletion mutation in the upstream NS1/2 common exon that shifted the 2018 PTC out of the NS2 open reading frame. This suggested that there was recognition and communication of reading frame between exons on a pre-mRNA in the nucleus prior to or concomitant with splicing.

An Sp1-binding site and TATA element are sufficient to support full transactivation by proximally bound NS1 protein of minute virus of mice

The minute virus of mice (MVM) P38 Sp1-binding site and TATA box, inserted in an otherwise heterologous plasmid background, could be transactivated to high levels by the MVM NS1 protein targeted proximally to these sequences, demonstrating that these core promoter regulatory elements are sufficient to support essentially wild-type levels of NS1-transactivated expression and suggesting that NS1 may act directly or indirectly with Sp1 and or elements of the general transcription machinery. Accordingly, we show that bacterially generated NS1 can interact strongly, independent of nucleic acid bridging, and most likely directly with Sp1 in vitro and can associate, in a nucleic acid-independent manner, with endogenous Sp1 as it exists in a complex transcriptionally active murine nuclear extract NS1 achieves the same fold activation of an isolated TATA element over its low basal level and can also be demonstrated to interact efficiently and specifically with the general transcription factors TBP and TFIIA (alpha, beta) in vitro.

Cross-protection test of an avian poxvirus isolated from houbara bustards

An avian poxvirus was isolated previously from the houbara bustard (Chlamydotis undulata). We carried out a cross-protection test on 66 captive-bred canaries. Thirty-five canaries were vaccinated with a commercial canary poxvirus (CP) vaccine. Three weeks later all 66 birds were assigned randomly to six different groups: group Ia (n = 14) was vaccinated and challenged with houbara bustard poxvirus (HP) strain; group Ib (n = 13) was vaccinated and challenged with a CP strain; group Ic (n = 7) was vaccinated and not inoculated; group IIa (n = 14) was nonvaccinated and challenged with HP strain; group IIb (n = 11) was nonvaccinated and challenged with a CP strain; and group IIc (n = 7) was not vaccinated and not challenged. Vaccinated groups (Ia, Ib, Ic) had no losses and remained healthy. All of the birds (100%) in group IIb died within 10 days, and 10 birds (71.4%) of group IIa died within 20 days. The nonvaccinated control group (IIc) remained healthy. Poxvirus was isolated from the liver, digestive tract, lungs, and inoculation lesions of nonvaccinated dead CP- and HP-challenged birds. Secondary bacterial infections were higher among nonvaccinated HP-challenged birds (85.7%) than in nonvaccinated CP-challenged birds (25%). The results of this experiment reveal a degree of immunogenic relatedness between CP and HP strain and support the recommendation that houbara bustards be vaccinated with a CP vaccine.

Can angiographic findings predict which coronary patients will benefit from enhanced external counterpulsation?

Enhanced external counterpulsation is an effective treatment for chronic angina. Theoretical considerations predict greatest benefit in patients with at least 1 patent conduit in this group of 50 patients (all of whom improved clinically). Improvement in radionuclide stress perfusion imaging was seen in 80% of treated patients and was inversely related to extent of coronary disease.

Prediction of sudden cardiac arrest: risk stratification by anatomic substrate

The prognostic importance of coronary artery anatomy to specific outcomes including ventricular tachycardia/fibrillation was evaluated in 372 consecutive patients undergoing cardiac catheterization at University Hospital at Stony Brook between 1981 and 1984. The hypothesis that proximal left anterior descending artery narrowing before the first septal perforator had a specific relationship to survival was again tested in this cohort. The population was prospectively followed for 8 years, with all clinical management decisions made independently by the patient's primary or referring physician. Multivariate statistical and life table analyses were performed after comprehensive follow-up. Significant narrowing in the proximal left anterior descending artery was associated with an increased risk of sudden cardiac death (p = 0.0002). Abnormalities of contractility in the diaphragmatic segment of the left ventricle in addition to an elevation of the left ventricular end-diastolic pressure and the presence of congestive heart failure (p < 0.05) were other contributory variables. Outcome in patients with proximal left anterior descending coronary artery disease who underwent aortocoronary artery bypass to the artery demonstrated improved survival (p < 0.05). Risk stratification of patients at high risk for sudden cardiac death is possible and may allow identification for an aggressive approach or interventional trials.

Internal cardioverter defibrillator: component failure

Sudden death occurred in a patient with congestive cardiomyopathy, sustained ventricular tachycardia refractory to amiodarone, and an automatic internal cardioverter defibrillator. Interrogation of the AICD at the time of death was indicative of malfunction. Postmortem analysis documented component failure involving a voltage regulating transistor resulting in prolonged charge times.

Recurrent torsade de pointes type ventricular tachycardia in intracranial hemorrhage

Two out of 72 cases of intracranial hemorrhage-induced polymorphous ventricular tachycardia with typical Torsade de Pointes morphology are presented. Both patients had marked QTc prolongation more than 550 ms. In one patient (QTc: 669 ms) Torsade de Pointes degenerated into fatal ventricular fibrillation. Even though polymorphous Torsade de Pointes type ventricular tachycardia is rare during the clinical course of intracranial hemorrhage, attention should be given to the QT interval. QTc prolongation more than 550 ms may carry a high risk of Torsade de Pointes type ventricular tachycardia and ventricular fibrillation.

[Incidence of ventricular arrhythmia relative to the QT interval in spontaneous intracranial hemorrhages]

A prospective study was done in 54 patients with acute spontaneous intracranial haemorrhage, 27 of them with subarachnoid bleeding and 27 with primary intracerebral haemorrhage. The frequency of ventricular arrhythmias was registered by continuous long-term ECG and the incidence of QT prolongation by daily standard ECG registration. Prolongation of frequency-corrected QT-interval (QTc) developed in 9 patients with subarachnoid haemorrhage and in 10 with intracerebral haemorrhage. For assessment of time-relation between QT-interval and ventricular arrhythmias the results of corresponding long-term ECG and standard ECG were used and two groups were defined: group A (149 tapes) = QTc less than or equal to 450 ms, group B (43 tapes) = QTc greater than 450 ms. In group B singular frequent ventricular extrasystoles, couplets and non-persistent ventricular tachycardias occurred more frequently though not significantly so. Persistent ventricular tachycardias occurred significantly more frequently in group B (14% vs. 1%, P less than 0.01). In three tapes of group B, all of them with QTc prolongation of more than 550 ms persistent ventricular tachycardias with typical "torsade de pointes " morphology were seen. The results show that QTc prolongation of more than 450 ms occurs in a third and significant ventricular arrhythmia in nearly half of patients with spontaneous intracranial haemorrhage. Persistent ventricular tachycardias occur almost only in cases of QTc-prolongation. Pronounced QTc prolongation of more than 550 ms is rare. However, it can give rise to torsade de pointes and ventricular fibrillation.

Complications after combination of chemotherapy and radiation for malignant brain tumours

The combination of chemotherapy and irradiation for the treatment of malignant intracerebral tumours is increasing, and survival times longer than those after monotherapy are reported. The suitability of simultaneous radio-chemotherapy using BCNU-Bleomycin, a regimen in which has been followed 38 patients of this hospital (up to 31 December 1981) is critically discussed. Statistics of 30 patients with treatment ended by 31 December 1980 and case histories of two patients with fatal complications, aspergillosis in the one and necrotizing colitis in the other, are presented. The value of the various agents used for chemotherapy is discussed with respect to the survival rates and observed side effects in all the patients. The use of Bleomycin is questioned.

Malignant gliomas - glioblastoma multiforme and astrocytoma III-IV with extracranial metastases. Report of two cases

The authors describe two rate cases of extraneural metastases of glioblastoma multiforme and of astrocytoma III-IV, but with different distribution routes. In the first case - astrocytoma III-IV - via the lymphatic system, with metastases in the cervical lymph nodes; in the second case-glioblastoma-via the blood system, with metastases in the sternum and vertebrae. Survival times were 18 months in the astrocytoma case (operation plus irradiation), and 6 months in the glioblastoma case (operation, irradiation, and chemotherapy). The discussion deals with the possible paths of the metastases, the connection between metastatic spread and survival time (in the longer surviving patient the metastases were discovered together with the recurrence), and problems in deciding the individual therapy.