“Water-in-salt” electrolytes enable the use of cost-effective aluminum current collectors for aqueous high-voltage batteries

Anodic aluminum dissolution is strongly suppressed in highly concentrated aqueous electrolytes.

Patient-prosthesis mismatch and left ventricular remodelling after implantation of Shelhigh SuperStentless aortic valve prostheses

AIM

Aortic valve replacement is a standard procedure for the treatment of severe aortic valve stenosis. Due to lower flow velocities stentless valves are associated with a more effective regression of left ventricular hypertrophy in comparison to stented valves. However, mismatch between body surface area and valve size supports unfavourable hemodynamic results. The aim of the study was to analyze hemodynamic parameters by echocardiography after implantation of the Shelhigh SuperStentless bioprosthesis and to analyze the occurrence of patient-prosthesis mismatch and left ventricular remodelling in this specific valve type.

METHODS

A total of 20 patients with severe aortic stenosis underwent implantation of a Shelhigh Super Stentless prosthesis. Clinical and echocardiographic assessment was done prior to, immediate after and six months after surgery.

RESULTS

All surgical procedures were successful, no surgery-related complication was documented perioperatively. One patient died after development of multiorgan failure. Echocardiography during the first eight days after surgery showed mean gradients of 16 mmHg, mean valve orifice areas of 1.8 cm(2) and indexed effective orifice areas at 0.95 cm(2)/m(2). Six-months follow-up data were obtained in 19/20 patients. There were no relevant changes in echocardiographic hemodynamic findings at the time of follow-up measurements. Significant regression of left ventricular hypertrophy was shown (P=0.0088). A patient-prosthesis mismatch occurred in one patient (0.54 cm(2)/m(2)). No recurrent symptoms were documented.

CONCLUSION

Patient-prosthesis mismatch after implantation of SuperStentless Shelhigh prosthesis is rare. A significant regression of left ventricular hypertrophy could be shown after six months. Hemodynamic valve function assessed by echocardiography may be predicted early after surgery.

Prevalence and patient awareness of selected potential drug interactions with self-medication

BACKGROUND AND OBJECTIVE

In community pharmacies potential drug interactions between prescription only medicines (POM) and over-the-counter (OTC) drugs purchased for self-medication arise mainly in two situations: (i) if an OTC drug is purchased by a passer-by customer whose prescribed drug therapy is not known; or (ii) if a POM or an OTC drug is requested by a regular customer whose prescribed drug therapy is usually recorded. With this study we aimed to assess the prevalence of potential drug interactions with selected POM and OTC drugs in passer-by and regular customers as well as their awareness of these potential drug interactions.

METHODS

Data were collected in 14 community pharmacies in the region of Basel, Switzerland by observation of customer contacts and interviews with passer-by customers purchasing selected OTC drugs, and telephone-interviews with regular customers treated with selected POMs identified in community pharmacies' databases. The selected POMs and OTC drugs are drugs which could lead to clinically relevant drug interactions of varying severity but manageable through different interventions such as adjustment of dose and its timing and/or monitoring of the therapy, and avoidance of the combination by choosing an alternative treatment.

RESULTS

Of 1183 passer-by customers observed, 164 (14 x 4%) purchased at least one of the selected OTC drugs. One hundred and two (62 x 2%) of those subjects were interviewed. Forty-three (42 x 2%) mentioned taking prescribed drugs, and three of them were exposed to potential drug interactions of moderate severity. Out of 592 regular customers selected from the community pharmacy database, 434 (73 x 3%) could be interviewed. Sixty-nine (15 x 9%) of them were exposed to a potential drug interaction between purchased OTC drug for self-medication and their POM. Furthermore, 116 (26 x 7%) regular customers were exposed to potential drug interactions within their prescribed drugs and in 28 (6 x 5%) multiple (>or=2) potential drug interactions were found. Two hundred and three (46 x 8%) regular customers were aware of potential drug interactions between their POM and OTC drugs. Ninety-six (47 x 3%) of them were informed by their prescribing physician and 52 (25 x 6%) by their community pharmacist. Awareness of potential drug interaction was higher in younger customers [odds ratio (OR) 0 x 95; 95% confidence intervals (CI) 0 x 93, 0 x 97, P<0 x 0001] and higher for drug interactions classified as 'severe' [OR 1 x 79; 95% CI 1 x 16, 2 x 77, P=0 x 009].

CONCLUSION

Efforts to increase awareness of potential drug interactions is needed. Although community pharmacies are adequately equipped with computerized drug interaction surveillance systems this is often not applied to self-medication. Vigilance for potential interactions of all drugs, including those sold over the counter, should be increased.

Aortic valve replacement after previous coronary artery bypass grafting: experience with a simplified approach

AIM

Aortic valve replacement (AVR) after previous coronary artery bypass grafting (CABG), particularly in a patent left internal thoracic artery (ITA), is a challenge. Avoidance of injuring the patent graft and ensuring myocardial protection are important issues in the management of these patients. The aim of this study was to evaluate a simplified surgical approach to these reoperations.

METHODS

Between January 2003 and June 2005, 19 of 287 AVRs performed at our institution were in a patient subset (mean age 70 years, range: 62-82) who received AVR after previous CABG surgery. The aortic valve gradients were between 50 and 107 mm Hg. Our operation strategy followed the KIS-principle (keep it simple): both femoral vessels were cannulated using the Seldinger technique. Only the area around the ascending aorta and the right atrium was dissected to permit x-clamping, aortotomy, and catheterization for retrograde cardioplegia and a left ventricular vent. The anterior aspect of the heart and the left side, where the ITA was embedded and patent, were left untouched and not clamped.

RESULTS

The mean interval between the first and second operation was 6.5 years. Fourteen patients received biological prostheses. Four patients received an additional surgery at the time of AVR. The mean operating time was 267 min; the mean AoX-clamp time was 63 min. One patient died because of severe heart failure. In all others the postoperative course was uneventful.

CONCLUSIONS

We believe that the indication for AVR in patients scheduled for CABG should be re-evaluated. In those in which Redo-surgery for new or increased valve stenosis is indicated, a simple and safe surgical option is presented.

Stress-induced attenuation of brain stem activation following intestinal anaphylaxis in the rat

Intestinal anaphylaxis triggers neuronal activation in the nucleus tractus solitarius (nTS) of the rat brain stem. Stress may modulate reflex circuitry in the brain stem and facilitate intestinal inflammatory responses. We hypothesized that stress would modulate central neuronal activation during intestinal anaphylaxis. NTS neurons were activated following intestinal antigen challenge in sensitized Hooded Lister rats but not in negative controls (P < 0.05). The number of Fos-positive neurons following intestinal anaphylaxis decreased in animals exposed to water-avoidance stress (P < 0.05), although serum levels of rat mast cell protease II were not different in stressed and unstressed animals, indicating a similar degree of mast cell degranulation. Stress seems to inhibit neuronal activation in the rat brain stem during intestinal inflammation without modulation of the inflammatory response itself. This may have implications for a potential efferent neuronal modulation of inflammatory responses in the gut.

Repair of a postinfarct ventricular septal defect on the beating heart. Surgical considerations

Postinfarct ventricular septal defect (VSD) still remains associated with a high mortality and morbidity. Despite the development of modern surgical techniques and medical care it continues to be a difficult therapeutic challenge. This report describes a case of a 70-year-old female patient, who presented with a postinfarct VSD after having anterior wall infarction. She presented with left heart failure, pulmonary hypertension and left to right shunt of 78% (Qp/Qs=4.3). The patient was operated on using cardiopulmonary bypass on the beating heart. The closure was performed with a Dacron-patch and a single bypass to the diagonal branch using the left internal thoracic artery. Postoperatively the patient did well and was discharged in good condition on the 13th postoperative day. We conclude that postinfarction VSD can be repaired on cardiopulmonary bypass avoiding cross-clamping. This method is helpful for the outcome as well as for the early postoperative recovery of elderly patients.

Aortic arch surgery using moderate systemic hypothermia and antegrade cerebral perfusion via the right subclavian artery

BACKGROUND

Surgery of the aortic arch avoiding profound systemic hypothermia and using antegrade or retrograde cerebral perfusion has recently been popularized. This usually renders the CPB and surgical field set-up more complex. We propose a simple method achieving a similar effect.

METHODS

During a 6-month period, 7 patients (median age 72 years) underwent surgery involving the aortic arch with cannulation of the right subclavian artery for arterial return. There were 6 acute type A dissections and one ascending aorta and arch aneurysm. After commencing CPB, the ascending aorta was clamped and reconstruction of aortic valve and root were initiated. Patients were cooled to a tympanic temperature of 25 - 27 degrees C. CPB was then stopped, and the arch was opened and inspected from inside. While resuming arterial perfusion via the right subclavian artery, the arch branches were clamped sequentially from right to left under observation for back flow. Bilateral radial artery pressure and temporal transcutaneous oxygen saturation were always monitored.

RESULTS

In all cases, the aortic valve was spared using remodeling and resuspension techniques. 2 complete arch, 2 partial arch and 3 proximal arch replacements were performed. Mean times were 183 (113 - 321) minutes for CPB and 120 (67 - 213) minutes for aortic cross-clamping. Maximal systemic circulatory arrest time was 82 min. One patient died in the hospital due to MRSA sepsis with a normal CCT scan. All others were discharged in good condition.

CONCLUSION

The initial experience with this simple technique of antegrade cerebral perfusion avoiding profound systemic hypothermia and the possible disadvantages of femoral artery cannulation appears promising.

Growth and development of children to 4 years of age after repeated antenatal steroid administration

It is common practice to repeat antenatal steroid administration after 7 to 10 days in women who continue to be at risk for preterm delivery. However, safety and efficacy of repeated courses have not been established. Mothers of singleton infants who had more than five courses of betamethasone (80-120 mg cumulative dose) were eligible for this cohort study. Index patients (IP) were compared to concurrent controls who had < or = 1 course but were matched for sex and gestational age. Of 35 IP born between 1986 and 1995 in a single perinatal centre, 28 were available for follow-up and could be matched. There was no difference between groups with respect to maternal age and gestational age at delivery. Median gestational age at initial treatment was 26.3 weeks (25th percentile 25.1 weeks, 75th percentile 27.2 weeks) in IP. There was no significant difference between groups in head circumference, length and body weight at birth and at age 4 years. The ability to sit and to walk without assistance and to use two-word phrases was attained at similar ages. The use of glasses or hearing aids, allergies, asthma or recurrent upper respiratory infections were not reported more frequently in IP.

CONCLUSION

This study failed to ascertain adverse long-term effects of repeated antenatal steroid administration in infants and children to the age of 4 years. In contrast to a similar Australian study, we were unable to demonstrate a lower birth size in exposed infants even though our sample size for women with more than five courses and their cumulative doses were larger.

[Effect of repetitive prenatal corticosteroid medication on intrauterine growth and growth in early childhood]

OBJECTIVE

The evaluation of the effects of repeated antenatal corticosteriod (CS) medication on birth size and size at the age of 4 years.

METHODS

82 children exposed to CS initially between 26 and 28 weeks of gestation were matched with 82 controls of the same gestational age and sex.

RESULTS

No differences were observed between the CS and control groups with regard to weight, head circumference, and length at birth and at the age of 4 years.

CONCLUSIONS

Our study failed to demonstrate that repetitive antenatal medication with CS in order to induce lung maturation has a negative impact on intrauterine growth and growth in early childhood.

Recurrent cardiac myxoma: why it occurs. A case report with literature review

Two years after surgical removal of a right atrial myxoma, recurrences were found in both atria: multiple tumors in the right atrium and one tumor in the left atrium. All were subsequently removed. There was no further recurrence during the following 3 years. We report on an unusual case which, to our knowledge, is the first time that such a case appears in the literature. We also discuss the clinical symptoms, diagnostic aspects, as well as details of a literature review regarding recurring myxoma. We think the recurrence in our case was due to totipotent multicentricity of the tumor. Previous studies showed that the recurrence might be due to the following reasons: inadequate resection, or multifocal pattern behaviour of a benign myxoma, either in the same or in a different location as the primary tumor. Familial disposition may also play a role in recurrent development. The abnormal DNA ploidy pattern of myxoma patients showed a high recurrence.

Percutaneous fenestration of the aortic dissection membrane in malperfusion syndrome

We present two cases of malperfusion syndrome due to aortic dissection type-B. A supra-renal blind sac phenomenon resulted in renal failure and absent femoral pulses in both patients. Additionally, one patient suffered from spinal cord ischemia, the other from severe abdominal pain. By interventional techniques, catheter perforation of the blind sac was achieved. The resulting re-entries were enlarged with a balloon catheter. Distal perfusion without pressure gradients was restored by this technique in both patients and resulted in complete relief of symptoms. Percutaneous fenestration of the aortic dissection membrane may be an alternative to operative treatment in malperfusion syndrome.

A post-receptor defect of adenylyl cyclase in severely failing myocardium from children with congenital heart disease

The aim of this study was to determine whether a defect at the post-receptor level of adenylyl cyclase may also contribute to the decreased effectiveness of cAMP-increasing agents in severely failing patients with congenital heart disease. The severity of congestive heart failure in 31 patients with congenital heart disease was graded by a scoring system which included a description of historical and clinical variables. Patients were divided into a group with no or mild heart failure (score < or = 6) and a group with severe heart failure (score > 6). beta-Adrenoceptor-stimulated adenylyl cyclase activity was significantly decreased by 65% in patients with severe heart failure in comparison to the group of patients with no or mild heart failure. In addition, receptor-independent adenylyl cyclase stimulation by forskolin was reduced by 52% in patients with score > 6 compared to patients with score < or = 6. This post-receptor defect of adenylyl cyclase was apparently due to a decrease in the activity of catalytic subunit of adenylyl cyclase as adenylyl cyclase stimulation by forskolin in the presence of Mn2+ which uncouples catalytic subunit from the G proteins, G(s) and G(i), was also significantly diminished in the patients with severe heart failure. In contrast, the level of inhibitory G protein alpha-subunits was apparently not different in the two groups. In summary, the data indicate that a defect at the catalytic subunit of adenylyl cyclase apparently contributes to the decreased effectiveness of cAMP-increasing agents in severely failing patients with congenital heart disease.

Catheter-induced pulmonary artery perforation during cardiac surgery: intraoperative surgical management

A case of pulmonary artery rupture due to Swan-Ganz catheterization is reported. A 73-year old women undergoing coronary artery bypass grafting developed massive endotracheal bleeding during weaning from the cardiopulmonary bypass and inflation of the balloon of the Swan-Ganz catheter. As bleeding could not be controlled by endobronchial Fogerty catheter blockade, resection of the lateral segment of the middle lobe was necessary before bypass could be terminated. The postoperative course was complicated by an abscess formation in the right middle lobe of the lung which required operative revision.

Emergency aortocoronary bypass grafting after failed percutaneous transluminal angioplasty versus elective bypass grafting

From January 1980 through July 1994 fiftyseven patients underwent emergency coronary bypass grafting (CABG) after unsuccessful percutaneous transluminal angioplasty (PTCA), (Group I). This group was compared with a cohort of 57 patients, who underwent elective coronary bypass grafting (Group II). The 2 groups were compared in the rate of perioperative myocardial infarction, amount of blood loss, rethoracotomy because of bleeding, use of blood units and products, and length of stay in the intensive care unit. The data of both groups were retrospectively analyzed. Significant differences were observed: Perioprative myocardial infarction in group I was 18 patients (31%) versus 2 patients (3%) in group II (p<0.0008). Amount of blood loss was higher (p<0.038), and the use of packed red blood cells was higher too (p<0.000) in group I. The length of stay in the intensive care unit was longer (p<0.000) in group I. Six rethoracotomies (10%) occured in group I versus 0 in group II. There were no hospital mortalities in either groups. We conclude there is a significant increase in morbidity in patients with emergency CABG after failed PTCA than patients who underwent elective CABG.

Long-term results after aortic valve replacement with the Mitroflow pericardial valve

From September, 1986 through December, 1989, 121 patients underwent aortic valve replacement with the Mitroflow pericardial valve. There were 70 males (58%) and 51 females (42%), with an average age of 71 years (range 50-85 years). Reported here are the long-term results from these patients. Concomitant cardiac procedures were performed in addition to aortic valve replacement in 38 patients (31%); Coronary artery revascularization in 27 patients (22%); 4 patients (3%) had combination aortic/mitral valve replacement; mitral valve reconstruction in 4 patients (3%) and 3 patients (2%) had other additional procedures. Following surgery, standard postoperative examinations were performed every six month for 2 years; then yearly thereafter. At these times valvular function assessed echocardiographically. Current follow-up extends to 7 years (mean = 5 years) for surviving patients. Postoperative mortality for all observation period is as follows: Early deaths (> or =30 days postop) = 6 patients (5%), late death (>30 days) = 18 patients (15%). Valve-related causes of death included cerebral insult (thromboembolism) in two patients (one 10 months, other 15 months postoperatively). Postoperative valve-related morbidity included prosthetic endocarditis (1 patient) one year postoperatively; degenerative prosthetic failure (1 patient) 27 months postop; cusp tear (1 patient) with minimal hemodynamic changes after four years. In the patients with endocarditis and failure, a second successful operation corrected the problem. Also, in two patients antithrombolitic therapy related hemor-rhage occurred (one 9 months, the second 11 months postoperatively). This therapy was a result of atrial fibrillation, and we do not recommended it. In conclusion, we find that the Mitroflow pericardial heart valve gives adequate long-term results, especially in elderly patients with a small aortic ring, with very satisfactory quality of life.

Heart diseases following mediastinal irradiation: surgical management

Twelve patients underwent cardiac surgical procedures after having previously received irradiation of the mediastinum for various types of malignancies (Hodgkin's disease, carcinoma of the breast and seminoma). The patients' ages ranged from 39 to 69 years (mean 57 years); nine patients were female and three male. The average length of time from radiation to surgery was 15 years (3-24 years interval). The patients were divided into two groups according to the type of heart disease: Group I included seven patients who developed coronary artery disease (CAD) despite minimal risk factors. Three asymptomatic patients developed sudden myocardial infarction. In two patients the myocardial infarction was complicated (with ventricular septal defect in one and ventricular septal defect plus ventricular aneurysm in the other). All seven patients were surgically managed. Internal thoracic artery (ITA) was used in three patients as a conduit of myocardial revascularization. There were two hospital deaths in this group. The five patients in Group II underwent aortic valve replacement for aortic stenoses. Prior to the irradiation, none of the patients had a documented history of rheumatic fever, bacterial endocartitis, significant murmur, etc. There were no deaths in this group. Intraoperative findings for both groups included thickening and/or fibrosis of the ascending aortic wall, coronary arteries and aortic valve tissue. Epicardium was whitish colored and thickened.

Relationship between Operating Variables and Temperature of Elastomer Entering the Mold on a Coaxial Screw/Pot Injection Molding Machine

The conclusions from this study are : 1. A linear model can be easily developed and is a useful tool to aid in setting up an injection molding machine. 2. An elastomer temperature in the holding chamber close to the 3-min induction-time temperature usually yields reasonable cure times without scorch in the coaxial screw/pot machine described. 3. Material properties, especially viscosity, seem to have a relatively minor effect on elastomer purge temperature because of low shear rates. However, in a mold with small runners viscosity could have a significant effect on elastomer temperature.