Absorption and bioavailability of oestradiol from a gel, a patch and a tablet

OBJECTIVES

To compare oestradiol and oestrone concentrations and bioavailability after a single dose and at a steady state during oral oestradiol valerate, transdermal oestradiol gel and transdermal oestradiol patch treatments.

METHODS

Two open, randomised, cross-over studies were conducted. In the first study, 12 healthy postmenopausal women received 1.5 mg oestradiol as a transdermal gel or a 2 mg oestradiol valerate tablet daily for 14 days. In the second study, 15 postmenopausal women were treated for 18 days with 1.5 mg oestradiol gel or a transdermal patch releasing oestradiol 50 microg/24 h (replaced every 72 h). Venous blood samples for serum oestradiol and oestrone measurements with RIA were taken until 24 or 72 h after the first and last doses.

RESULTS

The tablet and the transdermal gel yielded similar serum oestradiol profiles with a peak concentration 4-5 h after administration. The patch resulted in relatively stable oestradiol levels during the mid third of the wearing time whereas much lower levels were observed in the beginning and towards the end. There was no difference in the fluctuation between the peak and trough oestradiol levels between the gel (56 or 67%) and the tablet (54%) while the fluctuation was greater with the patch (89%). The bioavailability of oestradiol from the gel was 61% as compared with the tablet and 109% as compared with the patch. The gel was not bioequivalent with the tablet or the patch.

CONCLUSIONS

The doses used of the transdermal gel and the patch roughly corresponded to each other with regard to the amount of oestradiol absorbed whereas the bioavailability from the tablet was significantly higher than from the gel. The lack of bioequivalence, the different serum oestradiol profiles and the large intersubject variability suggest that individual dose adjustments may be needed when changing administration form.

Infrarenal endoluminal bifurcated stent graft infected with Listeria monocytogenes

Prosthetic graft infection as a result of Listeria monocytogenes is an extremely rare event that recently occurred in a 77-year-old man who underwent endoluminal stent grafting for infrarenal abdominal aortic aneurysm. The infected aortic endoluminal prosthesis was removed by means of en bloc resection of the aneurysm and contained endograft with in situ aortoiliac reconstruction. At the 10-month follow-up examination, the patient was well and had no signs of infection.

Folate, vitamin D, and iron intakes are low among pregnant Finnish women

OBJECTIVE

To evaluate dietary habits and nutrient intake of Finnish pregnant women, to relate these to the use of dietary supplements, and to explore possible dietary variations according to age and education.

DESIGN

A random dietary survey using two five day estimated food records.

SETTING

Pregnant women from 13 maternity clinics in the city of Oulu, Finland.

SUBJECTS

One hundred and eighteen pregnant women in their third trimester.

MAIN RESULTS

The main sources of energy were cereal products and milk products. The consumption of fish and poultry was low. Women with a higher educational level consumed more vegetables, fruit, fruit juices, and tea and less sausages, inner organs and coffee than women with a lower educational level. Younger women (< 25 y) consumed more sugar and pork and less berries, butter and inner organs than older women. On average 15% of the total energy was supplied by protein, 33% by fats, 52% by carbohydrates, and 12% by sucrose. Compared to the Nordic nutrition recommendations, the proportion of polyunsaturated fatty acids and the intake of dietary fibre were low and the intake of sugar high. The intakes of vitamins and minerals met or exceeded the recommended allowances, except for vitamin D, folate, and iron. Of the subjects 70% used dietary supplements. With the exception of vitamin D, folate, and iron, both the supplement users and non-users had an adequate nutrient intake from their diet.

CONCLUSIONS

A balanced diet covers the increased nutrient requirements during pregnancy, with the exception for vitamin D, folate, and iron. The use of dietary supplements during pregnancy is excessive and partly focused on the wrong nutrients. Young and less educated, and smoking pregnant women need more nutritional guidance.

Neuroprotective role of ornithine decarboxylase activation in transient focal cerebral ischaemia: a study using ornithine decarboxylase-overexpressing transgenic rats

Nuclear magnetic resonance imaging (MRI) was used to study dynamics of maturation and the size of ischaemic stroke lesions in rats with greatly increased activity of ornithine decarboxylase (ODC). Syngenic rats, either with or without chronic pre-ischaemic treatment with an ODC inhibitor, alpha-difluoromethylornithine (DFMO), as well as ODC-overexpressing transgenic rats were subjected either to transient middle cerebral artery (MCA) occlusion or permanent occlusion of the cortical branch of MCA. The two models were chosen to assess the role of ODC activity in damage caused by ischaemia and reperfusion, respectively. Diffusion of water was quantified by means of the trace of the diffusion tensor (D(av) = 1/3 Trace D) to assess the extent of energy failure and cytotoxic oedema, whereas the spin-spin relaxation time (T2) was used as a quantitative indicator of irreversible damage by MRI. Exposure to transient MCA occlusion resulted in significantly smaller stroke lesions in the ODC-overexpressing transgenic (246+/-14 mm3) than in syngenic (320+/-9 mm3) or DFMO-treated (442+/-63 mm3) rats as determined 48 h after the occlusion. The differences in sizes were due to smaller lesions in the cortical tissue (transgenic vs. syngenic) or both in cortical and striatal regions (transgenic vs. DFMO-treated animals). The degree of irreversible oedema was greater in DFMO-treated rats than in syngenic or transgenic animals indicating accelerated development of a permanent damage in the absence of ODC induction. Cortical infarct following permanent MCA occlusion developed faster in the DFMO-treated than in syngenic or transgenic rats as the lesion sizes at 10 h were 26.2+/-4.3 mm3, 14.2+/-2.3 mm3 and 12.3+/-1.9 mm3, respectively. However, the stroke volumes by 48 h were not statistically different in the three animal groups. The present data demonstrate that ODC activation is an endogenous neuroprotective measure in transient cerebral ischaemia.

Minimally invasive coronary artery bypass grafting using the right gastroepiploic artery

BACKGROUND

Anastomosis of the left internal thoracic artery to the left anterior descending artery without sternotomy and without cardiopulmonary bypass is a standard approach in minimally invasive coronary artery bypass grafting. To expand the indications for minimally invasive coronary artery bypass grafting from one-vessel disease to two-vessel disease, we began to perform anastomosis of the right gastroepiploic artery (RGEA) to the right coronary artery (RCA).

METHODS

From February to November 1996, an RGEA graft was used in 25 of the 100 patients who underwent minimally invasive coronary artery bypass grafting at our clinic. Eleven of the patients had only RCA disease and 14 had both RCA and left anterior descending artery disease. One of the operations was a redo coronary artery bypass grafting. The RGEA was anastomosed to the RCA through a laparotomy incision and the left internal thoracic artery was anastomosed to the left anterior descending artery through a left anterior thoracotomy. In 5 patients, the RGEA was lengthened by venous grafting.

RESULTS

All patients underwent angiography after operation; 82.6% of the RGEA grafts and all the left internal thoracic artery grafts were functioning well. In three of the four nonvisualized RGEA grafts, the percentage of proximal stenosis of the RCA seen on postoperative angiography was not critical (40%, 50%, and 50%, respectively), allowing significant competitive flow through the native bypassed RCA. The patency of all the RGEA grafts without competitive flow was 95%, with a 95% confidence interval of 75.1% to 99.9%.

CONCLUSIONS

The indications for minimally invasive coronary artery bypass grafting could be extended to primary operations in patients with left anterior descending artery and RCA lesions by using both the left internal thoracic artery and the RGEA.

Comparison of sotalol and metoprolol in the prevention of atrial fibrillation after coronary artery bypass surgery

New-onset atrial fibrillation (AF) is frequent after coronary artery bypass grafting (CABG), and beta-blockers decrease its incidence. To examine whether a beta-blocker with class III properties is superior to a pure one, 191 consecutive patients undergoing CABG were randomized to receive oral sotalol, 120 mg daily (n = 93), or metoprolol, 75 mg daily (n = 98), postoperatively. The doses were adjusted if beta-blockade was inadequate or excessive. AF occurred in 16 (16%) of 98 sotalol patients and in 30 (32%) of 93 metoprolol patients (p < 0.01). Symptoms related to beta-blockade or proarrhythmia did not appear. After CABG, sinus heart rate increased in both groups (p < 0.001) but less in the sotalol patients (p < 0.001) throughout the postoperative period. Corrected QT duration (by the Bazett equation) was prolonged after the operation in both groups (p < 0.001), whereas uncorrected QT duration at similar heart-rate levels were prolonged only in sotalol patients (mean increase, 31 ms; 95% confidence interval, 2042 ms; p < 0.01). Uncorrected QT durations at similar heart-rate levels were longer during sotalol (compared with metoprolol) treatment (p < 0.05). Heart rates or QT durations did not differ between the patients with or without AF. In conclusion, sotalol significantly reduces the incidence of AF after CABG. Although a marked class III effect is demonstrated with relatively low doses (as prolonged ventricular repolarization) in direct comparison unbiased by any rate correction, its contribution as an enhanced antifibrillatory mechanism in the postoperative state remains unconfirmed.

Steady-state pharmacokinetics of oestradiol gel in post-menopausal women: effects of application area and washing

OBJECTIVE

To investigate the effect of cutaneous application area on oestradiol absorption using an oestradiol gel for transdermal use. Furthermore, the effect of washing of the application site on oestradiol pharmacokinetics was studied.

DESIGN

Open-label, randomised, three-way cross-over study.

SETTING

A clinical pharmacokinetic research unit.

SUBJECTS

Sixteen healthy postmenopausal volunteers.

INTERVENTIONS

During three treatment periods, subjects were treated with 1 mg oestradiol (1.0 g Divigel/Sandrena 0.1% gel), applied on the thigh to a skin area of 200 cm2, 400 cm2, or on an area 'as large as possible'. Blood samples were drawn during steady-state (on days 14-15) immediately before application and at regular time intervals thereafter.

MAIN OUTCOME MEASURES

Serum oestradiol levels were measured for determination of peak concentration (Cmax), time to peak concentration (tmax) and bioavailability using the area under the time concentration curve (AUC0-24).

RESULTS

Bioavailability from a 200 cm2 area was 2-fold higher than that from the largest possible area (P < 0.05). Oestradiol peak plasma concentration from a 200 cm2 area was higher than from the two larger areas (P < 0.05), which did not differ significantly from each other. Washing of the application site 30 min after application reduced the bioavailability from both the 200 cm2 and 400 cm2 application areas (P < 0.01), but peak plasma concentration from the 200 cm2 area only (P < 0.01). Time to reach peak plasma concentrations was significantly reduced with all three application areas by washing.

CONCLUSION

A higher oestradiol absorption was achieved from a smaller application area. No marked differences were observed in the pharmacokinetics between 200 cm2 and 400 cm2 application areas, which are those recommended for this oestradiol gel preparation.

Studies on psychomotoric effects and pharmacokinetic interactions of the new calcium sensitizing drug levosimendan and ethanol

Levosimendan (CAS 141505-33-1) is a calcium sensitizing drug intended for the treatment of congestive heart failure. In animal experiments levosimendan has potentiated the sedative effects of ethanol. Due to poor water solubility of the compound, ethanol is used as a diluent in the intravenous formulation. In this study the possible interactions between levosimendan and ethanol in human have been studied. Twelve healthy male volunteers were included in this double-blind, randomized, cross-over study. The study consisted of three treatment periods: levosimendan 1 mg intravenously, levosimendan combined with ethanol orally and ethanol 0.8 g/kg alone. Blood samples for determination of levosimendan and ethanol concentrations were collected for 8 h after the dosing. To observe possible pharmacodynamic interactions psychomotoric tests were made before drug administration and 1h, 2h, 3h and 6h thereafter. These tests included Digit symbol substitution test, Maddox wing, Critical Flicker fusion and VAS-test for subjective assessment of performance status. Plasma levosimendan concentrations were not changed by the concomitant ethanol administration. Ethanol did not alter the pharmacokinetics of levosimendan except the volume of distribution of central compartment which was decreased. Levosimendan did neither affect elimination of ethanol. Levosimendan did not potentiate the psychomotoric effects of ethanol neither did it have any psychomotoric effects itself. In conclusion, levosimendan is not likely to have any psychomotoric adverse effects or any clinically significant interactions with ethanol.

Transgenic rats as models for studying the role of ornithine decarboxylase expression in permanent middle cerebral artery occlusion

BACKGROUND AND PURPOSE

Cerebral ischemia causes activation of ornithine decarboxylase (ODC) gene and subsequent accumulation of putrescine, which might either directly or indirectly affect the outcome of cerebral infarct. We developed a transgenic rat overexpressing human ODC, which was used to explore the effect of abnormally high putrescine concentration in the brain on the infarct volume after permanent middle cerebral artery (MCA) occlusion.

METHODS

The transgenic rats were produced by the pronuclear injection technique with the use of cloned human ODC gene. The right MCA was permanently occluded through craniotomy. ODC activity and polyamines were assayed in the infarcted and contralateral hemispheres. MRI was used to quantify T2 relaxation time, apparent diffusion constant (ADC), and infarct volume, which was also determined by 2,3,5-triphenyltetrazolium chloride.

RESULTS

Permanent MCA occlusion resulted in extensive activation of ODC, which was approximately sevenfold greater than in syngenic animals at 20 hours after occlusion. Consequently, putrescine increased from approximately 10 and 230 pmol/mg to 160 and 410 pmol/mg in the infarcted hemisphere of syngenic and transgenic animals, respectively, but all the other polyamines were unchanged. This high putrescine in the transgenic rats did not influence infarct size evolution, as determined by MRI, T2, ADC, or the infarct volume by 2,3,5-triphenyltetrazolium chloride at 48 hours.

CONCLUSIONS

Data from the ODC transgenic rat model show that the development of brain infarct after permanent MCA occlusion was not influenced by extensive levels of putrescine, indicating that this endogenous amine is not involved in maturation and spread of stroke lesion in vivo. Thus, it seems that ODC activation reflects an endogenous adaptation of neural cells to a noxious stimulus that does not directly influence lesion development.

Heart transplantation in Finland 1985-1995

BACKGROUND AND AIMS

Since improved immunosuppression in the 1980's, heart transplantation is a well established procedure to treat patients with end-stage heart failure. The first heart transplantation in Finland was performed in 1985. Since then the activity has gradually increased to a level of about 25 annual transplants. The aim of this report is to sum up the clinical experience during the first 11 years.

MATERIALS AND METHODS

From February 1985 till the end of 1995, 190 heart transplantations were performed in our institution. There were 176 males and 14 females ranging from 15 to 62 (mean 42.2) years of age. End-stage preoperative cardiac disease was dilating cardiomyopathy in 108 cases, coronary artery disease in 65 cases, valvular disease in 12 cases and congenital heart disease in five cases.

RESULTS

The 30-day hospital mortality was 29 out of 190 (15.2%). The actuarial survival was 77% at one year, 75% at two years and 73% at 10 years. The most common causes of death were rejection (11 cases), graft failure (11 cases), abdominal complications (six cases) and cytomegalovirus (CMV) infection (four cases). A total of 87 rejection episodes occurred in 53 patients consisting 28 per cent of patients. 44 rejections occurred within three months post transplantation. Significant infections were noted in 198 instances in 97 patients. These were of bacterial origin in 92, viral in 48, fungal in 12 and protozoal in 10 cases, and 36 such infections which responded to antibiotics favourably but in which the microbe remained unidentified. 138 infections (i.e. 80%) occurred within 6 months post transplantation. In viral infections cytomegalovirus (CMV) predominated (29 out of 48). The CMV infection was significantly milder in patients who were seropositive preoperatively than in preoperatively seronegative patients with seropositive donors. CMV infection was associated with increased risk of post-transplant coronary artery disease. Three years after transplantation some restoration of sympathetic nervous response was observed at orthostatic test in heart rate and blood pressure.

CONCLUSIONS

It can be concluded that 1) if a patient survives the three immediate postoperative months, his prognosis is good for the forthcoming years, 2) clinically significant rejections occur in less than one third of the patients, 3) cytomegalovirus is the most harmful agent post transplantation and a risk factor for post-transplant coronary artery disease and that 4) some restoration of sympathetic nervous control of the heart occurs within three years after transplantation.

Angiographic 5-year follow-up study of right gastroepiploic artery grafts

BACKGROUND

The right gastroepiploic artery (RGEA) has been used from 1987 in coronary artery bypass grafting in several clinical studies. However, the published 1- to 5-year patency rates have been dependent on the selection of patients for angiography.

METHODS

In our study, the RGEA was used from March 1987 to May 1990 for coronary artery bypass grafting in 31 consecutive patients, 25 male and 6 female. All but 1 patient had triple-vessel disease, and the mean number of distal anastomoses was 3.9 (range, 2 to 5). Internal thoracic artery grafts were used concomitantly in all patients.

RESULTS

One early and two late deaths occurred. All but 1 of the 28 surviving patients underwent clinical and angiographic follow-up examinations 3 months and 5 years after the operation. The 5-year patency of RGEA grafts was 82.1%, with a 95% confidence interval of 63.1% to 93.9%. In 4 of the 5 nonvisualized cases, the recipient coronary artery showed proximal stenosis of up to 70%, allowing substantial competitive flow. The 5-year patency of the RGEA graft was near that of the left internal thoracic artery, at 90.3%, and the right internal thoracic artery, at 94.4%; and superior to the 66.7% patency of venous grafts.

CONCLUSIONS

At 5-year follow-up, angiography of RGEA grafts showed good function and a smooth lumen, especially if the proximal stenosis was more than 70%.

Concentrations of tinidazole in gingival crevicular fluid and plasma in dogs after multiple dose administration

Tinidazole 15 mg/kg was administered to eight Beagle dogs with gingivitis or periodontitis twice daily for 3 days. Tinidazole concentrations in blood and gingival crevicular fluid (GCF) were measured 1, 3, 6 and 9 h after the morning dose each day. The concentration of tinidazole was determined by high performance liquid chromatography (HPLC). The mean concentration of tinidazole in GCF for each dog ranged from 6.05 to 9.32 micrograms/mL at different time points after the first dose, and on the first day the highest concentration was observed 6 h after the drug administration. Tinidazole concentrations were 34 +/- 4%-72 +/- 9% (mean +/- SEM) of simultaneous plasma concentration. At steady-state, on the third treatment day, the mean tinidazole concentrations in GCF ranged from 6.68 to 13.1 micrograms/mL, i.e. 44 +/- 6%-75 +/- 25% of the corresponding concentrations in plasma. Tinidazole concentration in GCF exceeded the MIC values for putative path-ogenic periodontal bacteria and it is concluded that, when indicated, tinidazole could be used for chemotherapy of periodontitis in dogs.

Magnetocardiographic localization of ventricular pre-excitation in a child with a congenital heart defect

Magnetocardiographic mapping was performed on a 2-year-old boy who suffered from the Wolff-Parkinson-White syndrome in association with a complex congenital heart defect. The pre-excitation site was determined noninvasively from the measured cardiac magnetic fields. The location was in the same anatomic region as found by intraoperative epicardial mapping. This result shows that magnetocardiography can be helpful for determining an accessory pathway also in patients with grossly abnormal cardiac anatomy.

Endothelin antiserum decreases volume-stimulated and basal plasma concentration of atrial natriuretic peptide

BACKGROUND

Endothelin-1 (ET-1) is the most powerful factor known to release atrial natriuretic peptide (ANP) in vivo and in cultured cardiac myocytes or preparations of atrium. We tested the role of endogenous ET-1 in the regulation of ANP release by passive immunization in anesthetized rats.

METHODS AND RESULTS

Intravenous injection of antiserum against ET-1 was shown to decrease basal and volume-stimulated plasma concentrations of ANP, whereas control serum was without effect. Antiserum generated in rabbits cross-reacted 100% with endothelin-2 and -3. In pentobarbital-anesthetized Wistar rats treated with ET-1 antiserum, plasma ANP concentration measured by radioimmunoassay was reduced by 37% from starting level after 10 minutes and by 30% after 60 minutes. Control rat serum had no effect on plasma ANP. Rapid intravenous infusion of 8 mL of 0.9% NaCl caused a sixfold increase of plasma ANP concentration in control rats but only twofold in rats pretreated with ET-1 antiserum (P < .01). This effect of ET-1 antiserum was dose dependent. ET-1 antiserum changed neither blood pressure nor heart rate significantly in anesthetized rats. Pretreatment with ET-1 antiserum did not affect the initial hypotensive response to intravenous ET-1 0.5 nmol/kg but significantly attenuated the subsequent hypertensive response to endothelin.

CONCLUSIONS

Endothelin may be a physiological modulator of both basal and stimulated ANP release.

Anaesthesia affects plasma concentrations of vasopressin, von Willebrand factor and coagulation factor VIII in cardiac surgical patients

Operative stress may affect haemostatic mechanisms through hormonal systems. As the endocrine stress response to surgery may be modulated by anaesthesia, we have altered stress hormone concentrations by using either opioid or inhalation based anaesthesia to study haemostatic mechanisms in cardiac surgical patients. Thirty patients undergoing coronary artery surgery were allocated randomly to receive fentanyl (non-stress group) or enflurane (stress group) as the main anaesthetic agent. After cardiopulmonary bypass (CPB), plasma arginine vasopressin (AVP) concentrations were significantly (P < 0.001) greater in the stress group (81.8 (46.9-142.9) pg ml-1, mean with 95% confidence limits) than in the non-stress group (5.8 (3.3-10.2) pg ml-1). Plasma noradrenaline and adrenaline concentrations increased similarly in both groups after CPB. Plasma concentrations of both von Willebrand factor (stress: 1.56 (1.33-1.79) IU ml-1; non-stress: 1.00 (0.76-1.25) IU ml-1) and coagulation factor VIII: C (stress 1.15 (0.87-1.44) IU ml-1; non-stress: 0.69 (0.55-0.80) IU ml-1) were significantly (P < 0.01) greater in the stress group than in the non-stress group after CPB. The results indicate that there is a temporal relationship between the increased plasma concentrations of AVP and von Willebrand factor and factor VIII: C. It is not clear if this indicates a causal relationship. However, variable stress control by anaesthesia may modify haemostasis in cardiac surgical patients.

Non-invasive magnetocardiographic localization of ventricular pre-excitation in the Wolff-Parkinson-White syndrome using a realistic torso model

This study was performed to evaluate the accuracy of magnetocardiography in non-invasive localization of the ventricular pre-excitation site in patients suffering from the Wolff-Parkinson-White (WPW) syndrome. Twelve WPW patients were studied, in whom the pre-excitation caused serious supraventricular arrhythmias refractory to drug therapy. Magnetocardiographic measurements were performed in a magnetically shielded room, and non-invasive localization was computed from preprocessed magnetic signals using a current dipole source in a realistically shaped digital torso. All patients underwent intra-operative multicatheter mapping and subsequent dissection of the accessory atrioventricular connection. The intra-operative localization results were marked on magnetic resonance images of the heart, where magnetocardiographic results were also superimposed to allow comparison. The average of the three-dimensional differences between the magnetocardiographic and the invasive results was 2.1 +/- 0.9 cm. In all cases, the computed localization result was in the same or adjacent anatomical region as the intra-operative result. The present results show that the magnetocardiographic method using a realistic torso model is capable of localizing pre-excitation sites with sufficient accuracy to provide extra information so that non-pharmacological therapeutic interventions can be applied.

The influence of intravenous magnesium sulphate on the occurrence of atrial fibrillation after coronary artery by-pass operation

To examine the influence of magnesium (Mg) on hypomagnesaemia and atrial fibrillation (AF) following coronary artery by-pass surgery, 140 consecutive patients were randomized to receive 70 mmol of magnesium sulphate intravenously (n = 69) or placebo (n = 71). Serum magnesium concentrations fell to 0.77 +/- 0.10 mmol.l-1 in the control group but rose to 1.09 +/- 0.17 mmol.l-1 in the Mg group (P < 0.001). The incidence of AF was 29% in the Mg group and 26% in the placebo group (NS). The AF patients were older, more of them had had prior AF episodes, their sinus rates (SR) were slower (78 +/- 10 vs 86 +/- 12 beats.min-1; P < 0.01) and serum Mg concentrations higher (0.89 +/- 0.21 vs 0.80 +/- 0.11 mmol.l-1; P < 0.05). The incidence of AF was 43% in the highest quartile of serum Mg and 23% among the rest (P = 0.056). In patients experiencing AF during the first three post-operative days, serum Mg concentrations were higher and SR slower on each day compared with non-AF patients. SR increased post-operatively less with high Mg levels (P = 0.044). In the Mg group, serum Mg and SR were the only independent predictors of AF. In conclusion, the incidence of post-operative AF is not decreased with magnesium. High Mg levels are likely to provoke AF probably by mechanisms that modify SR.

Effects of central and peripheral type benzodiazepine ligands on growth hormone and gonadotropin secretion in male rats

The action of central and peripheral type benzodiazepine ligands on growth hormone, luteinizing hormone and follicle stimulating hormone levels in serum were studied in male rats. Graded doses of Ro 5-4864, that binds to the peripheral type benzodiazepine receptors, clonazepam, a fairly pure central type agonist and diazepam, a mixed-type agonist, were given intraperitoneally. Also a benzodiazepine partial inverse agonist, FG 7142, was investigated. Clonazepam increased growth hormone levels at 0.2 mg/kg while higher doses were not active. Diazepam (5-25 mg/kg) was not effective. FG 7142 (15 mg/kg) and Ro 5-4864 (25 mg/kg) decreased growth hormone levels. Flumazenil, a central-type antagonist, reversed at least partially the effects of clonazepam and FG 7142, suggesting an effect through GABA-benzodiazepine complex. Elevation of growth hormone could be associated with anxiolysis and decrease of growth hormone with enhanced anxiety. Clonazepam (0.2-5 mg/kg) and diazepam (5-25 mg/kg) increased luteinizing hormone concentrations, but only the effects of 1 mg/kg of clonazepam and 5 mg/kg of diazepam reached statistical significance. Even FG 7142 caused a modest increase of luteinizing hormone at 5 mg/kg, but Ro 5-4864 rather decreased luteinizing hormone, although not significantly. Flumazenil (25 mg/kg) antagonized partially the effects of diazepam and clonazepam. Effects of Ro 5-4864 and FG 7142 were not modified by flumazenil or PK 11195, a peripheral-type mixed antagonist/agonist. Luteinizing hormone stimulation by benzodiazepine ligands may be a pituitary action while inhibition could be caused by the activation of the central GABAergic system. Serum follicle stimulating hormone levels were not significantly altered by central or peripheral type benzodiazepine agonists or antagonists.

Penetration of tinidazole into the gingival crevicular fluid in dogs

Tinidazole was administered as a single oral dose of 15 mg kg-1 to 12 dogs, and its concentration in the plasma and gingival crevicular fluid (GCF) was measured at one and two hours by high performance liquid chromatography. Tinidazole was detectable in GCF in five dogs at one hour (6.8 +/- 2.6 micrograms ml-1) and in six dogs at two hours (9.2 +/- 1.4 micrograms ml-1) and in all plasma samples. In those animals with no detectable tinidazole in GCF, either the concentration of tinidazole in plasma was low or the volume of the GCF sample was insufficient for determination. The observed tinidazole levels in GCF exceeded the minimal inhibitory concentration values for most anaerobic oral bacteria.

The performance of the probability density function in differentiating supraventricular from ventricular rhythms

The ability of the probability density function (PDF) of an automatic implantable cardioverter defibrillator (AICD) to reject supraventricular arrhythmias being recognized as ventricular was evaluated in 12 patients who were treated with an AICD (Ventak P 1600). The PDF criterion was monitored via telemetry with the sinus rate during exercise test. PDF was satisfied in seven patients at a rate of 75-144/min (mean 109/min), and not in the remaining five patients (mean rate 141/min). PDF was fulfilled in five of ten patients at a lower heart rate than predicted by the duty cycle index, derived from the ventricular patch lead electrogram at the implantation. Thus PDF is often fulfilled already at a moderately elevated sinus rate. If used to prevent inadvertent AICD discharges during rapid supraventricular rhythms, its performance should be tested in the individual patient.

Effects of central and peripheral type benzodiazepine ligands on thyrotropin and prolactin secretion

The cold-stimulated thyrotropin (TSH) levels in the rat were decreased by clonazepam (a central type benzodiazepine agonist), diazepam (a mixed agonist), FG 7142 (an inverse central type agonist) and Ro 5-4864 (a peripheral type agonist), clonazepam being the most potent and Ro 5-4864 the least active. Clonazepam and diazepam also decreased while FG 7142 increased prolactin (PRL) levels. Ro 5-4864 did not have any significant action. Clonazepam (1 and 5 mg/kg) and diazepam (15 mg/kg but not 25 mg/kg) decreased even the TRH-induced PRL levels. Only Ro 5-4864 (25 mg/kg) decreased TRH-induced TSH secretion but not significantly. The actions of central type compounds were antagonized by flumazenil but not by PK 11195. The weak effects of Ro 5-4864 were not antagonized by either antagonists. While the peripheral type benzodiazepine agonist only weakly affected the secretion of anterior pituitary hormones, the central type inhibition of TSH appears to be mediated through the hypothalamic TRH and that of PRL rather through the anterior pituitary gland. The sedating (or agitating in case of FG 7142) effect of high doses of benzodiazepine ligands may contribute to the changes in TSH and PRL levels.

Effect of food on absorption and hydrolysis of erythromycin acistrate

Effect of food on absorption of erythromycin acistrate (2'-acetyl erythromycin stearate, Erasis; CAS 96128-89-1) was studied in 14 healthy volunteers in a randomized cross-over design. The subjects were given 400 mg erythromycin acistrate enteric coated tablets b.i.d. for 4 days. On the 1st and 4th days the tablets were taken after an overnight fast or immediately after a light or a heavy breakfast. Erythromycin (E), 2'-acetyl-erythromycin (2AE), anhydroerythromycin and anhydro-2'-acetyl-erythromycin concentrations in plasma were analyzed chemically by HPLC. After a single dose the lag time of absorption (tlag) was significantly longer after both types of breakfasts as compared to fast. The tmax of E and 2AE were also somewhat delayed by food although tmax of 2AE after a heavy breakfast only differed statistically significantly from that of the fasting state. Food significantly delayed the absorption especially in some subjects since no drug was observed during the 12-h observation period in 2 and 5 of the subjects after a light and heavy breakfast, respectively. At steady state the delaying effect of food on absorption had almost disappeared. No significant differences were observed in Cmax- or AUC0-12-values between the fasting and the fed states both after a single dose or at steady state. It is concluded, that food does not affect the mean bioavailability of erythromycin acistrate neither the mean rate of absorption but in some subjects the absorption from enteric coated tablets might be significantly delayed.

Pharmacokinetics of tinidazole in dogs and cats

Pharmacokinetics of tinidazole in dogs and cats after single intravenous (15 mg/kg) and oral doses (15 mg/kg or 30 mg/kg) were studied in a randomized crossover study. Tinidazole was completely absorbed at both oral dose levels in cats and dogs. Peak tinidazole concentration in plasma was 17.8 micrograms/ml in dogs and 22.5 micrograms/ml in cats after 15 mg/kg p.o. The oral dose of 30 mg/kg resulted in peak levels of 37.9 micrograms/ml in dogs and 33.6 micrograms/ml in cats. The apparent total plasma clearance of the drug was about twofold higher in dogs than in cats, resulting in an elimination half-life that was twice as long in cats (8.4 h) as in dogs (4.4 h). The apparent volume of distribution was 663 ml/kg in dogs and 536 ml/kg in cats. Therapeutic plasma drug concentrations higher than the MIC values of most tinidazole-sensitive bacteria were achieved for 24 h in cats and for 12 h in dogs after a single oral dose of 15 mg/kg. From the pharmacokinetic standpoint tinidazole seems to be well-suited to clinical use in small animal practice.

Central and peripheral type benzodiazepine ligands displace [3H][3-ME-HIS2]TRH from its binding sites in the brain and the anterior pituitary and antagonize the effect of TRH in the rat duodenum

The effects of central (clonazepam, an agonist, and FG 7142, an inverse agonist), mixed (diazepam) or peripheral type (Ro 5-4864) benzodiazepine receptor ligands on the action of TRH on the transmurally stimulated rat duodenum and binding of [3H][3-Me-His2] TRH in the rat anterior pituitary, hypothalamus, cortex and brainstem have been studied. TRH dose-dependently inhibited the contractions of transmurally stimulated rate duodenum. Clonazepam (5 x 10(-6) M), diazepam (10(-5) M), Ro 5-4864 (10(-5) M) or FG 7142 (10(-5) M) attenuated the response of TRH in the rat duodenum. The action of these compounds was antagonized neither by the central type benzodiazepine antagonist flumazenil nor by peripheral type antagonist PK 11195 but instead PK 11195 itself counteracted TRH. TRH displaced [3H][3-Me-His2]TRH with Ki-values ranging 0.08 to 0.31 microM. Ki-values for clonazepam diazepam, Ro 5-4864, PK 11195 and FG 7142 ranged 6-117 microM, 3-23 microM, 20-67 microM, 20-40 microM and 260-420 microM, respectively, demonstrating fairly weak affinity to TRH-receptors. In saturation experiments, clonazepam and PK 11195 significantly increased KD but not Bmax of the labelled ligand while Ro 5-4864 increased both KD and Bmax. This indicates that all these compounds competitively inhibit the binding of [3H][3-Me-His2]TRH in the CNS which may also be the mechanism for their antagonism of the effect of TRH in the rat duodenum.

Atipamezole, benzodiazepines, bicucullin and tifluadom antagonize the effect of TRH on rat duodenum and displace it from brain and anterior pituitary receptors

The mechanism of action of the TRH induced inhibition of contractions of the transmurally stimulated rat duodenum has been studied. The effect of TRH was not antagonized by atropine, pentolinium, phenoxybenzamine, sotalol, methysergide, domperidone, diphenhydramine, cimetidine, aminophylline, antazolin, indomethacin, morphine, naloxone or tetrodotoxin. In contrast, the adrenergic alpha 2-antagonist atipamezole, the benzodiazepines chlordiaxepoxide and midazolam or GABA-A-antagonist bicucullin but not picrotoxin or SR-95531 attenuated the response to TRH. An opioid-kappa-receptor agonist having benzodiazepine structure, tifluadom, but not MR 2034 also diminished the response to TRH. However, these actions were not modified by the alpha 2-agonist medetomidine, benzodiazepine antagonist flumazenil, GABA-agonists muscimol or baclofen or naloxone, respectively. While the binding of [3H][3-Me-His2]TRH to the rat anterior pituitary, hypothalamus, cortex and brainstem homogenates was saturable and of high affinity, no saturable binding was observed in the duodenal smooth muscle. Agents that were effective in the duodenal preparation displaced [3H][3-Me-His2]TRH from its binding sites in brain homogenates and the inhibitory constants (Ki) were (in microM): 0.038-0.107 (TRH), 0.19-5.8 (chlordiazepoxide), 0.021-8.9 (midazolam), 1.5-17 (tifluadom), 60-210 (bicucullin) and 150-530 (atipamezole). Atipamezole, bicucullin and chlordiazepoxide caused competitive displacement indicated by the increased KD of the labelled ligand but no change in the Bmax while tifluadom increased KD and decreased Bmax. It is concluded that the inhibitory effect of TRH on the contractions of the duodenal smooth muscle is mediated directly by the smooth muscle and it is apparently specific for TRH.(ABSTRACT TRUNCATED AT 250 WORDS)

TRH-induced tachyphylaxis: present in the smooth muscle but not in the cardiorespiratory effects

The development of tachyphylaxis to the pressor, tachycardiac, ventilatory and smooth muscle effects of thyrotropin-releasing hormone (TRH) was studied. Subsequent administrations of increasing doses of TRH (0.1-1000 nmol/kg intracerebroventricularly), at 20 min. intervals in urethane-anesthetized rats dose-dependently increased the mean arterial blood pressure, heart rate and minute ventilation volume. At all doses the effect on mean arterial blood pressure was apparent at least 20 min. after each injection whereas at low doses (0.1-1 nmol/kg) the duration of the effects on heart rate or minute ventilation volume were shorter. The cardiorespiratory effects of TRH 10 nmol/kg intracerebroventricularly did not subside completely within an observation period of 1 hr. However, a repeated administration of TRH at 1 hr resulted in the levels of mean arterial blood pressure, heart rate and minute ventilation volume not statistically different from the peak levels of the first injection. While the cardiorespiratory effects of TRH were long-lasting, the TRH induced inhibition of the contractions of the rat duodenal smooth muscle lasted only 12-18 sec. The TRH-treated duodenal preparation responded normally to noradrenaline but remained unresponsive to further administrations of TRH until washed extensively. When the medium after cessation of the TRH response was transferred into another chamber with an untreated preparation, a full response was resulted. Inhibitors of TRH metabolism, bacitracin, EDTA and iodoacetamide, did not prolong nor enhance the response. Likewise, a stable TRH-analogue MK-771 did not produce any longer response than TRH. It is concluded that no tachyphylaxis was produced to the neurally mediated pressor, tachycardiac or ventilatory effects of TRH.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbachol differs from classical muscarinic agonists in producing long-term desensitization in smooth muscle

In the rat and guinea-pig antrum and in the guinea-pig trachea, carbachol (10(-3) M) desensitized the smooth muscle to the contracting action of other muscarinic drugs and BaCl2. In spite of extensive washing, the smooth muscle was completely unresponsive 30 min after the exposure to carbachol and still partially unresponsive after 75 min. None of the classical muscarinic agonists, i.e., acetylcholine, methacholine or bethanechol, showed such a long-term desensitizing effect when tested in identical conditions. Bethanechol (10(-3) M) desensitized the rat antrum heterologously but this desensitization ceased already after 5 min. Carbachol desensitized the rat antral smooth muscle also in a calcium-free incubating medium. It is concluded that the carbachol-induced heterologous long-term desensitization is not related to persisting contraction, changes in receptors or blockade of calcium influx.

Selective cardiorespiratory activity of an iodinated analog of thyrotropin-releasing hormone (TRH)

The biological activity of thyrotropin-releasing hormone (TRH) and its analogs 4(5)-I-Im-TRH and 2,4(5)-I2-Im-TRH was assessed by means of their effects on: 1) the mean arterial pressure (MAP), 2) heart rate (HR), 3) ventilation minute volume (MV), 4) contractility of the rat duodenum, and 5) concentrations of thyrotropin (TSH) or prolactin (PRL) in serum. Also their binding to TRH-receptors in brain homogenates was studied. In urethane-anesthetized rats TRH ICV increased MAP, HR and MV. 4(5)-I-Im-TRH was equally as active as TRH on HR and MV but a significant elevation in MAP was observed only at a dose 100-fold to that of TRH. However, the maximal responses of 4(5)-I-Im-TRH and TRH did not differ. In conscious rats, TRH 1A elevated MAP and HR but 4(5)-I-Im-TRH was active on MAP only. 2,4(5)-I2-Im-TRH was devoid of cardiorespiratory activity. TRH dose-dependently inhibited the contractions of the rat duodenum while the iodinated analogs lacked such an activity. To induce a significant release of TSH several hundred times more of 4(5)-I-Im-TRH and over 1000 times more of 2,4(5)-I2-Im-TRH were needed as compared to TRH. The iodoanalogs elevated PRL levels only at doses 2000-fold higher than those of TRH. The iodoanalogs displaced [3H][3-Me-His2]TRH [( 3H]MeTRH) from its binding sites at concentrations about 1000 times higher than those of TRH. Substitutions of the histidyl moiety of TRH in 4(5)-I-Im-TRH and 2,4(5)-I2-Im-TRH resulted in substantial loss of the endocrine activity. While the di-iodinated analog was practically devoid of any biological activity the monoiodinated analog exerted similar cardiorespiratory activity to that of TRH.

Indications for and risks in reoperation for coronary artery disease

Seventy-one coronary artery bypass grafting (CABG) reoperations were performed during a 17-year period, comprising 2.7% of all CABG operations. The main indication (in 87%) was vein graft failure alone or combined with other causes. Progression of disease in native coronary arteries was the sole indication in only 4 of the 71 cases. There were seven perioperative deaths, mainly due to myocardial infarction. Significant perioperative complications arose in 36 cases, including intraoperative lesion of a previous left internal mammary graft (16.2%) or of the right ventricle or anterior descending branch of the left coronary artery (2.8%). Postoperative low output syndrome appeared in 13 patients (18.3%), in seven of whom myocardial infarction was verified. Postoperative bleeding required resternotomy in six cases (9.1%). Because of the heightened operative mortality and morbidity risks, indications for redo CABG should be individualized. A well functioning internal mammary artery graft may be a relative contraindication. Accurate knowledge of the previous operation is essential and, especially in young patients, the possibility of reoperation should be taken into consideration at initial CABG.

Laser for harvesting of the internal mammary artery

In 12 piglets both internal mammary arteries were dissected from the thoracic wall without a surrounding pedicle, using low-current electrocautery for one artery and continuous wave contact Nd:YAG laser (12 W) for the contralateral vessel. Changes in the arterial flow surface were evaluated by scanning electron microscopy immediately after dissection and 2 and 5 days postoperatively. Laser dissection was easier, more accurate and as fast as electrocautery. Moderate to severe degenerative changes and endothelial desquamation were seen in the electrocautery group after dissection, but lesser changes in the laser group. The changes decreased within the next 5 days, but two electrocauterized vessels showed thrombosis at 5 days. Stripping of the internal mammary artery with either method requires great care, and Nd:YAG laser offers a promising alternative to electrocautery in harvesting of that artery as a pedicled graft.

Primary cardiac tumours--operative treatment of 20 patients

This report describes a series of 20 patients operated on for a primary cardiac tumour. The majority of the tumours (16) were benign myxomas; 12 of them were located in the left atrium, two in the right atrium and two were biatrial. Two lipomas were found; one was epicardial and the other was located in the left atrium. The only intraventricular tumour was a malignant left ventricular myosarcoma. The propensity of intracardiac tumours to embolize was distinctive. Nine of the 16 myxomas presented with peripheral embolization, and in two patients surgery was complicated by fatal perioperative cerebral embolization of myxomatous tissue. Furthermore, in one patient embolization of a left atrial lipoma necessitated amputation of her left arm before cardiac surgery. Late postoperative recurrences were found in two patients with atrial myxomas. In one of them, reoperation showed that the tumour had grown at that site in the interatrial septum where the original pedicle had been excised. One patient developed severe mitral valve regurgitation and underwent replacement with a prosthetic valve at reoperation. Otherwise our late follow-up study showed that the results of surgery were usually excellent even though mild echocardiographic abnormalities were not uncommon. Our experience emphasizes the embolic potential of intracardiac myxomas and suggests, furthermore, that to avoid recurrences excisions with wide margins should be preferred. Echocardiography is an optimal method for the follow-up of these patients.

Continuous monitoring of ventilation in spontaneously breathing anesthetized rats

A method for continuous monitoring and recording of ventilation rate and tidal volume in spontaneously breathing anesthetized rats is described. The system is based on a hot wire flow meter placed in connection with the tracheotomy tube. In cardiovascular experiments routine monitoring of ventilation was found useful in the following instances: 1) detection of ventilatory disorders, 2) detection of central effects of drugs, 3) interpretation of results in cases where cardiovascular drugs alter ventilatory function.

Right gastroepiploic artery as a coronary bypass graft

Between November 1987 and April 1988, the right gastroepiploic artery (GEA) was used as a coronary artery bypass graft in 11 patients, 9 men and 2 women. In 1 of them, the GEA was used because no veins were available; in the others, the GEA was used to avoid the use of vein grafts. The GEA was anastomosed to the right coronary artery in all patients, and internal mammary artery grafts were used to bypass the left anterior descending and circumflex coronary arteries. All patients survived the operation. There were no early and, to date, there have been no late complications of the abdominal component of the operation. Postoperative coronary angiography showed a patent right GEA in 9 patients (82%). In 1 patient the GEA was occluded, probably because of an enlarged liver. If the long-term patency of right GEA grafts is similar to that of internal mammary artery grafts, wider use of this viable graft is indicated.

Angiographic findings in patients exhibiting ischemia after oral dipyridamole

We have assessed the angiographic features of a group of 37 patients given oral dipyridamole and 37 patients given matching placebo. Both groups represented severe coronary arterial disease and were studied prior to bypass surgery. Six patients (16%) had angina and 13 patients (35%) had electrocardiographic changes after dipyridamole. All the patients in the control group were nonresponders. In the group given dipyridamole the patients responding with angina had significantly more compromised collaterals than the patients without chest pain (P = 0.021). The same applied to the patients with electrocardiographic changes versus those with no electrocardiographic changes (P = 0.034). No differences between responders and nonresponders could be found in terms of the severity of coronary arterial disease, severity of anginal symptoms, exercise tolerance, antianginal medication, number of past myocardial infarctions, and left ventricular ejection fraction. In conclusion, the data strongly suggest that ischaemic responses to dipyridamole originate from myocardial steal accentuated by compromised flow in collateral vessels.

Prospective study of the etiology of diarrhea in adult outpatients and inpatients

A prospective study of the etiology of diarrhea in 253 adult outpatients and inpatients was conducted in Helsinki in 1985-86. The outpatients constituted 84.6% of all patients studied. A broad panel of diagnostic techniques was applied, including detection of bacteria and parasites in the feces and determination of the serologic responses to campylobacter, salmonella, Yersinia enterocolitica, and several viruses. Pathogens were identified for 28.5% of the patients. The commonest findings were Campylobacter jejuni/coli in 13.0% and Salmonella species in 7.1% of the patients. Mixed infections of several pathogens were found in 16 patients.

Is electrocautery safe for internal mammary artery (IMA) mobilization? A study using scanning electron microscopy (SEM)

Being the graft of choice, the internal mammary artery (IMA) is increasingly used for coronary artery bypass grafting. Presently, electrocautery is liberally used to mobilize both IMAs. Preservation of IMA flow surface was evaluated by scanning electron microscopy (SEM) after mobilization with either sharp dissection or electrocautery in five clinical patients undergoing coronary artery bypass surgery. Major side branches were secured with metallic clips. Specimens for SEM were harvested after heparinization but before institution of cardiopulmonary bypass from the terminal branches of both IMAs after they had been skeletonized with either mobilization method. When mobilization of the IMA was performed as a pedicle, the flow surface was well preserved in both groups. However, if a contact of the electrocautery blade with the wall of the IMA or with a metallic clip parallell to the wall was allowed, a clearly visible zone of endothelial damage, sometimes associated with mural trombus formation was observed. In conclusion, caution is needed with electrocautery. Thermal injuries of the IMA may remain undetected during surgery and cause graft occlusion later.

Surgical technique and operative mortality in coronary artery bypass. A postmortem analysis with castangiography

Post-mortem analysis with castangiography was performed on 54 patients who died within 30 days of coronary artery bypass surgery. Myocardial failure was the cause of 85% of the deaths. There were 215 coronary anastomoses (4.0 +/- 1.1/patient), 24% of which were non-functioning. Most of the occlusions were due to various technical failures. The most striking features were 1) high occlusion rate (25%) in sequential vein grafts and 2) disastrous complications of coronary endarterectomies. Compared with preoperative angiographic data, only 15 (28%) of the 54 patients were found to have 'complete' revascularization, with patent grafts and all stenosed coronary arteries bypassed. The need for recognition and avoidance of technical complications is stressed: Failures of surgical technique constitute a major risk factor in coronary artery surgery.

The possibility of using celiac trunk branches as coronary artery bypass grafts

The internal mammary artery has proved to be superior to the saphenous vein for coronary artery bypass grafting, because of its arterial nature and closer approximation in size to the coronary arteries. But the internal mammary artery cannot reach the posterior surface of the heart as a pedicled graft. Two suitable intra-abdominal grafts can reach that surface, viz. the right gastroepiploic artery and the splenic artery. In experiments on eight dogs (weight 9-13.5 kg), the gastroepiploic artery was found to be too small for coronary artery anastomosis, and therefore the splenic artery was used. The size approximation with coronary artery (diameter less than 1 mm) was good. Four dogs survived the month of the study. In two of them the anastomosis was patent, in another the splenic artery was patent despite occlusion of the anastomosis, and in the fourth dog both anastomosis and graft were thrombosed. The possibility of using visceral arterial grafts in coronary surgery is discussed.

Primary tumours of the ribs

Thirty-four primary rib tumours (24 benign, 10 malignant) were surgically treated in 1966-1985. The mean age was higher and the tumour diameter was greater in the patients with malignant, than in those with benign neoplasm. The benign tumours were excised without operative death. At follow-up after a mean of 12.3 years there was no recurrence of benign growth, but in two cases with initial diagnosis of chondroma a regrowth at the same site proved to be chondrosarcoma. Among the cases of malignant tumour there was one operative death from pulmonary embolism, after radical resection of sarcoma. None of the four patients with chondrosarcoma had recurrence 6-13 years after surgery. There was no long-term survival among the patients with other forms of sarcoma or malignant tumour of the reticuloendothelial system.

Abdominal aortic aneurysm and dissection after blunt trauma

A case of abdominal aortic aneurysm and dissection after blunt trauma is presented. Unlike traumatic lesions of the thoracic aorta, this condition seems to be extremely rare, and may therefore deserve publication. Conservative surgery (resection of the dissected intimal flaps, closure of the aortotomy with a Blalock-type vascular suture) gave good early and late (6 years follow-up) results.

Fever, leucocytosis and C-reactive protein after open-heart surgery and their value in the diagnosis of postoperative infections

The time course of body temperature (T), white blood cell count (WBC) and serum C-reactive protein (CRP) following uncomplicated open-heart surgery and the value of these three parameters in the diagnosis of postoperative infectious complications were analyzed in 153 patients. Preoperatively, all the patients had a normal T and the WBC level was under 10 X 10(9)/l. The CRP was elevated (over 20 mg/l) in five patients without having an influence on their postoperative courses. Postoperatively, T, WBC and CRP reached their maximum values during the first three days, decreasing gradually thereafter. Great individual variations in this average response to open-heart surgery were seen. Development of minor postoperative infections, mainly wound infection, (in 22 patients) were poorly reflected by these three parameters. However, a temperature exceeding 38 degrees C after the 6th postoperative day suggested presence of infection; less than 5% of patients without an infection had a temperature over this value. A secondary rise in CRP after the third postoperative day occurred in 20 patients and correlated well with postoperative complications; in 14 patients (70%) an infection became apparent, in three instances a probable infection was present, while two patients suffered from non-infectious complications. Only in one case (5%) did the cause for a secondary rise in CRP remain unknown. In major infections, i.e. mediastinitis, a CRP response occurred in all 12 patients, a temperature response in 11 patients (92%) and a WBC response in 10 patients (83%).

Hypothermia and circulatory arrest in reconstruction of aortic arch. A report of nine cases

From 1982 until October 1985 we operated 9 cases of aortic aneurysm involving the transverse aortic arch (5 male and 4 female, from 26 to 69 years). Two patients had an acute dissecting aortic aneurysm, the others had an aneurysm of the aortic arch involving also the ascending aorta in 5 cases and the descending aorta in 1. Three patients underwent aortic valve replacement and implantation of coronary orifices. Two patients had previously had AVR. The operation was carried out under cardiopulmonary by-pass. After obtaining 25 degrees C hypothermia the bypass was discontinued and the cerebral vessels were cannulated from inside of the opened aneurysm and perfused at a flow rate of 250 ml/min. The myocardium was protected by cold cardioplegia and topical cooling. During total circulatory arrest the distal aortic arch anastomoses were completed in 28-56 minutes. Then the by-pass was restarted and the rest of the operation was carried out as usual. One patient with an acute dissecting aortic aneurysm died on the 2 post-operative day due to brain damage and rupture of abdominal aorta. The other patients recovered well. There were no permanent neurological or myocardial complications. Three patients had a transient renal failure, one needing dialysis. The 8 survivors have done well 4-46 months after the operation.

Immediate hemodynamic effects of pericardial closure after open-heart surgery

Acute hemodynamic effects of a routine pericardial closure after cardiopulmonary bypass was studied in 29 patients undergoing cardiac surgery. Clinically, the pericardial closure was well tolerated. Pericardial closure resulted in an 8% decrease of cardiac output (p less than 0.01) while cardiac index remained normal (2.9 l/min/m2 +/- 0.6 SD). The effect of the pericardium on pulmonary arterial and wedge pressures, and on systemic arterial pressure was not significant. Central venous pressure increased from 8 +/- 2 mmHg to 9 +/- 3 mmHg (p less than 0.05) after pericardial closure and decreased to 7 +/- 3 mmHg (p less than 0.05) when the pericardium was reopened. Left ventricular end-diastolic cavity diameter by echocardiography decreased in 19 of the patients studied from 46 +/- 6 mm to 41 +/- 5 mm (p less than 0.01) when the pericardium was closed, and increased to 45 +/- 6 mm (p less than 0.01) after re-opening of the pericardiotomy incision. The hemodynamic effects of pericardial closure seem to result from limited ventricular filling.

Intrathoracic surgery for retained endocardial electrodes

Intrathoracic surgery for retained endocardial electrodes was performed in 12 patients; the indication for electrode removal was Staphylococcus aureus or epidermidis infection in 11 patients and malfunction in one patient. Two operations had to be performed on emergency basis. One was carried out because of myocardial rupture and cardiac tamponade after a tightly fixed electrode lead had been pulled out. The other patient was operated on because of ventricular arrhythmia arising from a malfunctioning lead which had slipped back completely after transsection into the right ventricle. Ten patients underwent elective surgery; cardiopulmonary bypass was needed in 6 of these. In one case a mitral prosthesis was replaced because of infection. Radical treatment is recommended for pacemaker infections and the removal of electrodes should be considered even if intrathoracic surgery is required.