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Biomedical subjects

H Jakob

Publications and source records attributed to H Jakob.

At least 19 recordsLinked to original sources
PubMed1998

Circulating interleukin-1 receptor antagonist (IL-1RA) serum levels in patients undergoing orthotopic heart transplantation.

In a pilot study we determined the serum levels of circulating interleukin-1 receptor antagonist (IL-1ra) in patients undergoing orthotopic heart transplantation and in control patients scheduled for open heart surgery without allograft transplantation. Blood samples were obtained from 12 transplant recipients and 7 controls prior to the operative procedures to determine baseline values. Serum levels of IL-1ra were measured within 12 h of decrossclamping of the aorta and every 24 h for the following 14 days. Endomyocardial biopsies were obtained weekly for the 1st month after transplantation. Compared to baseline values, IL-1ra serum levels 12 h after decrossclamping of the aorta were significantly higher both in the control group (507 +/- 165 vs 3980 +/- 452 pg/ml, P < 0.01) and among the transplant recipients (413 +/- 180 vs 4117 +/- 459 pg/ml, P < 0.01) IL-1ra levels remained significantly elevated for 2 and 5 days, respectively. There were no significant differences in the IL-1ra serum levels between the two groups throughout the observation period. Endomyocardial biopsies of two patients showed acute allograft rejection, Billingham grade IIIa and IIIb, respectively. In both cases, the rejection episodes were accompanied by a renewed and more pronounced elevation in the IL-1ra serum levels beyond 4000 pg/ml for at least 2 days. These preliminary results indicate that IL-1ra may be a nonspecific immune marker during the first few days after orthotopic heart transplantation and cardiopulmonary bypass. Moreover, renewed, prolonged increases in IL-1ra appear to be associated with rejection. Further studies are needed to confirm the predictive value of IL-1ra in the detection of acute allograft rejection.

Biomarkers↗
PubMed1998

Interruption of bronchial circulation leads to a severe decrease in peribronchial oxygen tension in standard lung transplantation technique.

OBJECTIVE: In clinical practice lung transplantation is the only procedure where the transplanted organ is left without its own arterial perfusion. With the interruption of the bronchial arteries the nutritive support is dependent on collateral flow by the pulmonary artery and the oxygen tension of desaturated central venous blood, representing an abnormal physiology. METHODS: To analyze this problem systematically, we used a standard single left lung transplantation model in the pig (n = 12). In accordance with the clinical standard, lung preservation was performed with modified Euro-Collins solution with addition of prostacycline. The duration of ischemia was set to 4 h. Before and after single left lung transplantation tissue oxygen tension in the peribronchial tissue was measured with Licox tissue pO2 microprobes. For validation, the myocardial tissue oxygen tension was recorded simultaneously. The hemodynamic assessment included continuous flow measurement of the left and right pulmonary artery using Transsonic ultrasound flow probes. After transplantation the animals were observed for 4 h. For hypothetic augmentation of collateral blood flow to the peribronchial tissue we administered Nitric oxide (10 ppm) to the ventilation in six pigs (group B). Six pigs (group A) served as a control without the addition of nitric oxide (NO). All pigs were ventilated with a FiO2 of 0.5 resulting in paO2 values between 160 and 200 mmHg. RESULTS: In both groups single lung transplantation led to a significant decrease in peribronchial tissue oxygen tension throughout the observation period. Pre-Tx values of peribronchial tissue oxygen tension (38.31 +/- 6.56 mmHg) decreased to 9.72 +/- 2.55 mmHg in group A and 10.3 +/- 3.61 mmHg in group B after 4 h, which could not be altered by a FiO2 of 1.0 (P < 0.0001). The addition of NO in group B led to a significantly augmented flow in the left pulmonary artery (0.63 +/- 0.31 l/min in group B vs. 0.46 +/- 0.26 l/min group A, P < 0.001) representing 67 vs. 49% of the pre-Tx flow in groups B and A, respectively, but the peribronchial tissue oxygen tension was not influenced (P > 0.05). In both groups A and B, the central venous pO2 did not differ in the postoperative period (41.83 +/- 3.27 mmHg group A vs. 43.26 +/- 2.98 mmHg group B) and was kept in a comparable range to the pretransplantation values (45.23 +/- 3.41 mmHg pre-Tx). CONCLUSIONS: The persistence of a very low peribronchial tissue oxygen tension in the early phase after lung transplantation cannot be influenced by improved pulmonary artery flow and solely relates to the central venous pO2, which cannot be augmented by the addition of NO. This mechanism might be a trigger for anastomotic healing problems, infectious complications and later development of obliterative bronchiolitis (OB).

Animals↗
PubMed1997

External stabilization of long-segment tracheobronchomalacia guided by intraoperative bronchoscopy.

BACKGROUND: Symptomatic obstruction of long-segment tracheal or bronchial portions either related to congenital instability or secondary to vascular compression are rare malformations, which remain difficult to manage. A method of external tracheal or bronchial stabilization is described. METHODS: From July 1992 to April 1995, 7 children (age range, 4 months to 4 years; mean age, 19 months) and 1 adult (age, 46 years) were operated on for severe respiratory insufficiency. In 4 cases of congenital tracheal instability, 2 children had associated type IIIb esophageal atresia. Both children with esophageal atresia had previous operations (two and three times, respectively): 1 child had aortopexy and division of a patent ductus arteriosus and another child had distal tracheal resection elsewhere, both without relief of malacia. All children were intubated and ventilated since birth for 11 to 15 months. Secondary tracheobronchomalacia due to vascular compression was seen in 4 patients caused by double aortic arch (n = 2) and persisting ligamentum arteriosum after previous ligation of a patent ductus arteriosus (n = 2), with 1 child ventilated thereafter for 5 months. Operation was performed with the aid of extracorporeal circulation in all patients but 1, and consisted of transection of vascular rings and persistent ligamentum Botalli (n = 5), closure of multiple ventricular septal defects (n = 1) and extensive mobilization of the tracheobronchial tree as well as the great arteries. External stabilization of the severely dysplastic distal trachea (n = 6) or left main bronchus (n = 2) was achieved by suspending the malacic segment within an oversized and longitudinally opened ring-reinforced polytetrafluoroethylene prosthesis. Multiple plegeted sutures were placed extramucosally to the dysplastic tracheal wall and the dyskinetic pars membranacea, as well as to the polytetrafluoroethylene prosthesis in a radial orientation. Guided by simultaneous video-assisted bronchoscopy, reexpansion of the collapsed segments was achieved by gentle traction on the sutures while tying. RESULTS: Stenosis-free tracheobronchial reexpansion was achieved in all patients, as seen on repeated bronchoscopies during hospitalization and thereafter. All patients were extubated within 1 to 12 days after the operation. There was one late death, unrelated to the procedure, in a 31-month-old child 20 months after the operation. All other patients are free of stridor and in excellent clinical condition 21 to 54 months (mean, 38 months) thereafter. CONCLUSIONS: The presented method of bronchoscopically guided external tracheobronchial suspension within a ring-reinforced polytetrafluoroethylene prosthesis immediately relieves severe malacia of the trachea or main bronchi in infants as well as adults without necessitating resection. Midterm preliminary data suggest that growth potential of the affected segment exists within the oversized polytetrafluoroethylene prosthesis.

Abnormalities, Multiple↗
PubMed1997

Spinal cord protection using hypothermic cardiocirculatory arrest in extended repair of recoarctation and persistent hypoplastic aortic arch.

OBJECTIVE: In recurrent coarctation collateral circulation may not be sufficient to maintain adequate perfusion of the lower body during the period of surgical repair. Different techniques such as interposition of a Gott-shunt, use of left heart bypass or hypothermic cardiocirculatory arrest are used to prevent spinal cord injury. METHODS: Twenty-eight operations for recurrent coarctation were performed in 26 patients following end-to-end anastomosis (58%), patch plasty (21%), subclavian flap aortoplasty (14%) and graft interposition (7%). Associated cardiac defects were present in 77% of the patients. Eleven patients who had adequate (> 50 mmHg) distal perfusion pressure during a test occlusion were operated on using simple cross-clamping (group I, mean age 8.5 +/- 3.8 years). In group I, end-to-end anastomosis was performed in nine patients and graft interposition in two patients. In 17 cases (including two patients from group I) with insufficient collateral circulation and with persistent hypoplasia of the arch, hypothermic cardiocirculatory arrest was used (group II, mean age 12.8 +/- 9.6 years). In group II end-to-end anastomosis was performed in three patients and graft interposition in 14 patients. Mean bypass-time was 116 +/- 36 min and arrest-time 33 +/- 16 min. Hypothermic cardiocirculatory arrest was begun when nasopharyngeal temperature was below 20 degrees C, corresponding to a rectal temperature of 24 +/- 3 degrees C. RESULTS: Hypothermic cardiocirculatory arrest allowed open reconstruction of the arch and/or complete or partial replacement of the arch and the coarctation segment. In-hospital mortality was 0 and 5.9% in group I and II, respectively. The one patient who died in group II had simultaneous correction of an anomalous pulmonary venous connection and death was unrelated to the method of coarctation repair. Reversible laryngeal nerve paresis was observed in two patients in group II, no other neurologic complications were observed in either group. Postoperative gradients over the repair site were less than 20 mmHg by Doppler-echocardiography. Two patients of group I had to have a second, early reoperation because of stenosis at the anastomotic site. Reconstruction of the distal aortic arch was then performed during hypothermic cardiocirculatory arrest. CONCLUSIONS: The use of hypothermic cardiocirculatory arrest in this special indication is a safe method which allows open reconstruction of the coarctation site and the aortic arch and protection of the spinal cord. The need for early reoperation because of inadequate repair may be reduced.

Anastomosis, Surgical↗
PubMed1997

Critical illness polyneuropathy: a new iatrogenically induced syndrome after cardiac surgery?

OBJECTIVE: Critical illness polyneuropathy (CIP) is a newly described severe complication after open heart surgery leading to tetraplegia for weeks to months. The purpose of the study was to gather further information on critical illness polyneuropathy developing in patients after cardiac surgery and to evaluate the hypothetical risk factors possibly related to the onset of this neurological disorder. METHODS: From July 1994 to October 1995, 7 out of 1511 patients undergoing open heart surgery developed critical illness polyneuropathy, which was diagnosed on the basis of electromyographic and nerve conduction features. The only common clinical finding was an intensive care unit (ICU) stay beyond seven days, therefore a similar group of 37 patients staying longer than seven days in the intensive care unit during the same period of time was evaluated and retrospectively compared to the 7 patients developing critical illness polyneuropathy. Univariate analysis of several traits was performed to evaluate possible risk factors. RESULTS: 4 Out of 7 patients in the CIP group died, all due to multiple organ failure, in contrast to 3/37 patients in the control group, again due to multiple organ failure. Patients developing CIP were staying significantly longer in the ICU (62+/-3 versus 14+/-8 days, P < 0.01) and had a significantly longer time on ventilator support (50+/-28 versus 7+/-13 days, P < 0.01) The incidence of sepsis was significantly higher in the CIP group than in the control group (85.7 versus 10.8%, P < 0.01). Compared to the control group the proportion of patients receiving corticosteroids (100 versus 10.8%, P < 0.01) and increased dosages of epinephrine and norepinephrine was higher in the CIP group (85.7 versus 35.1%, P < 0.05). Furthermore, the proportion of patients requiring chronic venovenous hemodiafiltration was significantly elevated in the CIP group (85.7 versus 5.4%, P < 0.01). CONCLUSIONS: CIP, despite it's benign nature due to it's spontaneous remission in patients who survive, is a disturbing complication following cardiac surgery which is associated with high mortality, a prolonged stay in the ICU, as well as an extended time on ventilator support. Interventions like chronic hemodiafiltration, the application of corticosteroids and the administration of high doses of catecholamines are more frequent in patients with CIP. Whether this indicates a causal relationship remains to be elucidated.

Adrenergic alpha-Agonists↗
PubMed1997

Direct visualization of leukocyte/endothelial cell interaction during extracorporeal circulation (ECC) in a new animal model.

OBJECTIVE: The clinical complications of extracorporeal circulation (ECC) have been linked to a systemic activation of cellular and humoral components and to a dysregulation of the microcirculatory compartment. Since to date only in vitro methods exist for evaluation, we developed an animal model to study the effects of ECC on the microcirculation. To establish the model, we assessed whether these effects are dependent on the duration of ECC. METHODS: Intravital fluorescence microscopy was used on the dorsal skinfold chamber preparation in chronically instrumented, awake Syrian golden hamsters. ECC was realized using a micro-rollerpump and a silicon tube shunting blood between the carotid artery and the jugular vein. ECC was performed in three groups for various times (2, 10 and 20 min) after application of heparin at 300 IU/kg body wt. In hamsters, the application of high-dose heparin releases endothelial bound superoxide dismutase (SOD), a natural scavenger of oxygen-derived free radicals. Protocol II assigned two groups receiving heparin at different doses of 50 and 2000 IU/kg body wt. RESULTS: ECC for 2 min served as control to exclude effects from hemodilution and resulted in a minimal induction of leukocyte/endothelial cell interaction. Isovolemic ECC for 20 min resulted in an increase in rolling (from 11 +/- 3 to 38 +/- 20%, mean +/- S.D., P < 0.05) and adherent leukocytes (from 19 +/- 16 to 215 +/- 145 cells/mm2, mean +/- S.D., P < 0.05) in postcapillary venules. Microhemodynamic parameters and functional capillary density were not significantly affected. Arterial blood pressure and heart rate were stable. Heparin at 2000 IU/kg inhibited post-ECC leukocyte adhesion following ECC, whereas 50 IU/kg showed no protective effects. CONCLUSIONS: Leukocyte/endothelial cell interaction, induced by blood contact with synthetic surfaces, was directly visualized in vivo. The number of adherent leukocytes was dependent on the duration of ECC. The application of high-dose heparin followed by release of SOD almost prevented leukocyte activation, suggesting a formation of oxygen free radicals during ECC. The new application of the hamster model may allow to study the underlying pathomechanisms and to develop therapeutic/prophylactic strategies to avert problems associated with ECC.

Animals↗
PubMed1997

Doubly angled pleural drain circumventing the transcostal route relieves pain after cardiac surgery.

Standard pleural drainage after cardiac surgery is accomplished through the intercostal space and the divided parietal pleural, often causing severe additional chest pain. To circumvent this route of insertion a doubly angled polyvinyl chloride drain was developed which can be placed via the median approach through the rectus abdominis muscle just beside the anterior mediastinal drains without irritation of the heart and parietal pleura into the phrenico-costal sinus.

Adult↗
PubMed1997

Predominant involvement of motor fibres in patients with critical illness polyneuropathy.

Critical illness polyneuropathy (CIP) is a recognized cause of muscle weakness and failure of weaning from a ventilator. In order to characterize the features of CIP, we have examined 28 consecutive surgical patients with severe sepsis using bedside electrophysiology. Of the 28 patients (median APACHE II score 31), 20 developed moderate to severe CIP, as shown by the presence of moderate to severe denervation activity on resting EMG. The median nerve compound muscle action potential (CMAP) amplitudes were reduced to 3.24 (SEM 0.48) mV, while sensory nerve action potential (SNAP) amplitudes obtained from the same nerve were normal (13.1 (1.9) microV). In approximately 50% of these patients, the reduction in CMAP exceeded 50% of the lower limit of normal. Similar results were obtained from stimulation of the ulnar nerve. We conclude that CIP is a major complication in patients with severe sepsis and prolonged artificial ventilation. It predominantly involves motor fibres and thus markedly interferes with weaning from the ventilator.

Adolescent↗
PubMed1996

Effects of metoprolol on myocardial beta-adrenoceptors and Gi alpha-proteins in patients with congestive heart failure.

OBJECTIVE: In human heart failure downregulation of beta-adrenoceptors and upregulation of Gi-protein alpha-subunits (Gi alpha) results desensitization of the myocardial beta-adrenergic signal transduction pathway and reduced positive inotropic effects of catecholamines. Metoprolol treatment has been shown to restore the reduced beta-adrenoceptor density in dilated cardiomyopathy. The main objective of the present study was to investigate whether metoprolol also decreases the elevated inhibitory Gi alpha levels in patients suffering from congestive heart failure. METHODS: Total Gi alpha was determined by pertussis toxin-catalysed ADP ribosylation and beta 1- and beta 2-adrenoceptor densities by radioligand binding in right ventricular myocardial biopsies of 18 patients with dilated or ischaemic cardiomyopathy (NYHA II-IV) before and after 3 months of therapy. Nine controls were treated with conventional therapy only [diuretics, digitalis, nitrates, angiotensin-converting enzyme (ACE) inhibitors], and nine received the beta 1-selective blocker metoprolol in addition (mean 98 +/- 12 mg daily). RESULTS: In biopsies from patients treated with metoprolol, Gi alpha significantly decreased to 74% of predrug value and total beta-adrenoceptor increased by a selective increase in beta 1-adrenoceptors (44.7 vs 34.0 fmol mg-1 protein). These effects were accompanied by significantly increased oxygen uptake at the anaerobic threshold (8.65 vs 6.95 ml . kg-1 . min-1). In the control group no significant changes in biochemical and clinical parameters occurred. CONCLUSION: Metoprolol partly reverses Gi alpha-upregulation and beta-adrenoceptor downregulation in heart failure, which might contribute to the clinical improvement of patients treated with beta-blockers.

Adrenergic beta-Antagonists↗
PubMed1996

Surgical treatment of acute endocarditis of the aortic valve with paravalvular abscess: considerations justifying the use of mechanical replacement devices.

OBJECTIVE: Early recurrency after surgery for acute endocarditis is a life-threatening complication. Allograft valves are supposed to have a higher resistance to recurrent infection, thus several authors claim them to be the replacement device of choice in cases of aortic endocarditis. However, allografts have two major drawbacks: their availability is limited, and most of the patients require reoperation for graft calcification of degeneration. Until now there has been no prospective study analysing whether early recurrency after surgery of acute endocarditis is associated with the mechanical valve per se or with factors related to the surgical technique or postoperative care. PATIENTS AND METHODS: We present a prospective study on 36 consecutive patients with acute endocarditis of the aortic valve with paravalvular abscesses. In this series, there were 5 women and 31 men with a mean age of 50.3 years. All patients were operated before a course of antibiotic therapy was completed. Abscesses were radically resected and the cavities closed either with direct suture or, if not possible, with Dacron patches. For aortic valve replacement, a mechanical valve was used in every patient. RESULTS: The early mortality in this series was 14%, only one patient experienced recurrent endocarditis and underwent reoperation. The results compare well with those achieved after valve replacements with allograft valves. CONCLUSION: We conclude that, even in cases of acute endocarditis, replacement of the aortic valve with a mechanical device is an acceptable alternative to the allograft, if radical surgical debridement and adequate antibiotic therapy are performed.

Abscess↗
PubMed1996

Different effect of inhaled nitric oxide on yucatan micropig with and without congenital ventricular septal defect.

A strain of Yucatan micropigs is known to have heritable ventricular septal defects (VSDs) and thus may develop overflow pulmonary hypertension. Since inhaled nitric oxide (NO) selectively dilates pulmonary vessels, we determined its hemodynamic and co-agulatory effects in this new animal model. Eight Yucatan micropigs were anesthetized with midazolam, piritramide (a synthetic opioid) and vecuronium bromide. The presence and the size of the VSD were determined by using transesophageal color flow Doppler echocardiography. Four animals showed VSDs of 1-2 mm size. Inhaled NO was then administered with increasing inspired concentrations of 0, 5, 10, 20, 40, 80 and again 0 ppm NO for 10-min periods. NO inhalation did not affect heart rate, right cardiac output, mean arterial pressure, pulmonary arterial wedge pressure, or central venous pressure. Inhaled NO in animals with proven VSDs decreased pulmonary artery pressure (PAP) in a dose dependent manner; 5 ppm NO reduced mean PAP from 25 +/- 2.3 mm Hg to 18 +/- 0.8 mm Hg (p < 0.05), while pulmonary vascular resistance (PVR) decreased from 954 +/- 143 dyn.cm. s-5 to 661 +/- 88 dyn.cm.s-5 (p < 0.01) at the same dose. The maximum reduction in mean PAP and PVR occurred when 80 ppm NO was inhaled. Yucatan micropigs without VSDs did not respond hemodynamically to NO inhalation. Methemoglobin levels remained unchanged during the entire study. Platelet function was assessed according to the method of BREDDIN and BORN (BORN 1962). Initial aggregation and slope were affected when NO inhalation commenced. Yucatan micropigs with VSDs may represent a suitable model for further research of the in vivo effects of inhaled NO.

Administration, Inhalation↗
PubMed1995

Effect of captopril on myocardial beta-adrenoceptor density and Gi alpha-proteins in patients with mild to moderate heart failure due to dilated cardiomyopathy.

In end-stage heart failure due to idiopathic dilated cardiomyopathy beta 1-adrenoceptors are downregulated and Gi alpha-proteins are upregulated. The aim of the present study was to investigate the influence of the angiotensin-converting enzyme inhibitor captopril on beta-adrenoceptor density and Gi alpha-proteins in sequential endomyocardial biopsies. Nineteen patients with mild to moderate congestive heart failure due to idiopathic dilated cardiomyopathy (NYHA Class II-III) were studied before and after 8-11 weeks of therapy. Patients were randomised into a captopril and a control group; 9 patients received captopril 12.5-50 mg per day, (divided in 2-3 doses) p.o. in addition to "conventional" therapy with digoxin and diuretics, and 10 controls received "conventional" therapy only. Echocardiography, spiroergometry, right heart catheterisation and endomyocardial biopsies were performed before (baseline) and after treatment. Compared to baseline, captopril increased total beta-adrenoceptor density by selectively increasing beta 1-adrenoceptors (31.6 vs 41.2 fmol.mg-1; p < 0.05) but had no significant effect on Gi alpha-proteins. The results indicate that treatment with angiotensin-converting enzyme inhibitors partly restores myocardial beta 1-adrenoceptor density, and this action effect may contribute to the clinical improvement of patients with idiopathic dilated cardiomyopathy treated in this way.

Adenosine Diphosphate Ribose↗
PubMed1995

Modified surgical concept for fulminant pulmonary embolism.

Surgical intervention in fulminant pulmonary embolism (PE) is still associated with an overall 30% fatal outcome which increases to about 60% when cardiopulmonary resuscitation (CPR) is necessary. Despite unfavorable conditions like hemodynamic instability, failed lysis or CPR, the surgical strategy might have a certain impact on the patient's outcome since 30-40% of the surgical mortality is related to persistent right heart failure and early thromboembolic recurrence. From 1/88 to 8/94 a total of 25 patients (15 females, 10 men, mean age 57 [25-78]) years underwent emergency pulmonary embolectomy with the use of the heart-lung machine. Seventeen patients were operated upon between 1988 and 1992. A standard approach by central pulmonary artery incision with extraction of adjacent pulmonary emboli using forceps, suction of Fogarty catheters was used. Six of these patients (35%) died, with four out of six operated upon under CPR. Since 1993 we have used a modified surgical strategy in eight patients. Five patients (63%) were operated on after or under CPR. In these cases, left and right pulmonary arteries were incised peripherally and all segmental arteries were desobliterated selectively using small suction devices. Thereafter the right atrium was opened and inspected. After removal of the inferior caval vein cannula all inferior body blood was taken with cardiotomy suction while both legs and the abdomen were massaged centripetally to mobilize additional fresh thrombotic material. In three cases up to 50 cm long thrombi could be delivered. All patients have survived to date with two patients receiving a LGM caval filter placed percutaneously after bilateral postoperative phlebography had revealed ongoing thrombotic disease. We conclude that selective desobliteration of every segmental pulmonary artery in combination with simultaneous clearance of major body veins from additional thrombotic material will probably lower surgical mortality in these critically ill patients.

Adult↗
PubMed1994

[The clinical significance of the ajmaline test in the noninvasive diagnosis of the Wolff-Parkinson-White syndrome].

A knowledge of electrophysiological parameters of accessory atrioventricular conduction pathways, such as effective refractory time and high conduction capacity in atrial fibrillation, make it possible to detect those patients who are at risk of life-threatening ventricular tachyarrhythmias. One criterion to identify these electrophysiological parameters is persistent pre-excitation after intravenous administration of ajmaline in Wolff-Parkinson-White (WPW) syndrome. Sensitivity and specificity of the ajmaline test in detecting patients at risk of life-threatening ventricular tachyarrhythmias were evaluated in 58 consecutive patients (22 females, 36 males; mean age 40.2 +/- 13 years) with the WPW syndrome. Pre-excitation was blocked after ajmaline in 43 patients (74%), pre-excitation persisting in 15 (26%). In 26 of the 43 patients with blocked pre-excitation the ajmaline test indicated short effective refractory time (< 270 ms) of the accessory pathway, and a high conduction capacity in 19 (minimal pre-excitation R-R interval during atrial fibrillation of < 250 ms). Sensitivity of the ajmaline test in the detection of a short refractory time was 33.3%, specificity 89.4%, while the corresponding values were 40.6% and 92.3% for the detection of accessory pathways with high conduction capacity in atrial fibrillation. These data show that the ajmaline test is not useful for estimating the electrophysiological characteristics of the accessory pathways. It is thus of only subordinate diagnostic value in predicting how much patients with the WPW syndrome are at risk of serious ventricular tachyarrhythmias.

Adult↗
PubMed1994

Circumscribed malformation and nerve cell alterations in the entorhinal cortex of schizophrenics. Pathogenetic and clinical aspects.

A postmortem histological comparison of 5 selected cases of schizophrenia with 5 non-schizophrenic controls showed a circumscribed malformation of the entorhinal cortex. The cortical alterations consisted mainly of a lack or a change of the characteristic island formations in layer II pre-alpha. Further, there were atypical neurons in layers II and III showing a conspicuous decrease of volume, often a change of the shape. They lay either in clusters or in columnar formations. These cells were considered "young neurons". The changes varied considerably from case to case and sometimes extended to all entorhinal layers. In one case the extension of the changes is described by means of serial sections in steps which extend over the whole rostral entorhinal region. Here, the striking architectural changes were formed in an exactly circumscribed sector and did not extend to the rostral hippocampal formation. On the whole, the changes are regarded as local migrational disturbances that occur during the second trimester of brain development. Neuronal displacements like these could give rise to various aberrant connections within the limbic system and related structures (e.g. the central position of the entorhinal region in circuits such as the entorhino-hippocampal loop, entorhinol-insula and entorhino-orbitofrontal reciprocal connections). Whereas alterations of the genetic programming of cell migrations may be suspected, various environmental influences (e.g. viral infections during the months III-V of pregnancy) appear to play a significant role. The malformations may be a decisive vulnerability factor for the later manifestation of the illness.

Adult↗
PubMed1994

[Induced labor with prostaglandin E2 gel after previous cesarean section].

With the rising rate of Caesarean sections, the number of pregnant patients with a previous Caesarean is increasing. Taking into consideration certain contraindications, it seems to be justified, to attempt induction of labour for vaginal delivery without major risk. However, the use of prostaglandins for cervical ripening in women with an unfavourable cervical status is particularly controversial. Thus, we analysed data from 385 trials of vaginal labour induction in a total of 522 patients with previous Caesarean section. Single or multiple cervical doses of prostaglandin-E2-gel had to be administered because of an unripe cervix (Bishop-score < 8) in 161 women for induction of labour for medical indications. 84.9% of those patients, in which labour induction was attempted after previous Caesarean section, delivered vaginally; 70% after two Caesareans. The highest success rates were seen after previous Caesarean for breech presentation, while there was still a vaginal delivery rate above 60% even after Caesarean for cephalopelvic disproportion or failure to progress. Maternal and foetal complications were seen with equal incidence in both study groups. Uterine ruptures totalling 0.5% were seen only in patients without cervical priming. Taking into consideration contraindications, intracervical application of PGE2-gel is a safe and effective method, even in patients after previous Caesarean section with clear advantages in case of an unripe cervix.

Administration, Intravaginal↗
PubMed1994

[Prenatal developmental disorders of brain structures in schizophrenic psychoses].

In recent years neuroimaging techniques have revealed various cerebral and structural variances in patients with schizophrenic psychoses. The best established findings are the enlargement of the lateral ventricles and discrete structural deficits in temporobasal structures of the cortex. Neuropathological investigations have detected subcortical as well as cortical variances. Subcortically, the volume of the striatum and the globus pallidus have been found to be enlarged in schizophrenics. Among the cortical deviations, the cytoarchitectonic disturbances of the rostral entorhinal region have been well documented and are especially important. According to neuropathological criteria, they are derived from disturbances of prenatal cell migration within the central nervous system. Due to its close anatomical and functional connection with the hippocampal formation and its being the assembly point of all sensory cortical areas, disturbances of this area could seriously impede the processing and filtering of information within the limbic system. The other hitherto reported structural anomalies, such as the disturbance to the radial order of hippocampal neurons, and the abnormal structures in the frontobasal orbital regions and the rostroventral insula, could be connected to the disturbances of migration within the entorhinal region; the former could be secondary, but still prenatal developments. Well documented are the architectonic changes in the rostral cingulate gyrus which is itself connected with the entorhinal region via the Papez circuit. These findings are supported and supplemented by the results of epidemiological studies which indicate a disturbance of brain development during the second trimenon of the prenatal period. Viral infections (Influenza A2) of mothers during this critical period appear to play an especially important role.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗