[Effect of prostaglandin F2 alpha on proliferation of corneal endothelial cells in vitro]. / Effekt von Prostaglandin-F2 alpha auf die Proliferation von Hornhautendothelzellen in vitro.

INTRODUCTION: Prostaglandins, especially PG-F2 alpha, have recently been introduced as a new local glaucoma medication. The modulation of cell proliferation and collagen synthesis in various tissues are the major effects of these agents. However, it is unknown whether PG-F2 alpha also modulates the proliferation of the corneal endothelium. METHODS: Bovine corneal endothelial cells (BCEC) were cultured according to established protocols. Experiments were performed after the 1st passage under serum-reduced conditions. A total of 10(4) cells/well were seeded and the cells were then incubated with different (5 x 10(-6) bis 5 x 10(-4) mg/ml) concentrations of PG-F2 (Sigma). The number of cells was determined every 24 h until day 5. Toxicity tests were performed by means of the trypan blue exclusion assay. RESULTS: PG-F2 alpha induced a significant stimulation of BCEC proliferation with all concentrations tested. At the highest concentration of PG-F2 alpha, a 2-fold increase in cell number was found after 5 days only compared to unsupplemented control cultures. No signs of cellular toxicity or morphological alterations could be detected in PG-F2 alpha-supplemented cells. DISCUSSION: For the first time, the present study demonstrates a stimulatory effect of PG-F2 alpha on the corneal endothelium. It appears that this effect is also induced by the PG-F2 alpha concentration determined in the aqueous humour of patients after topical latanoprost application. However, due to the strong contact inhibition of endothelial cells in situ, these results cannot be directly extrapolated to the situation in patients with topical latanoprost treatment.

Morphology and structural organization of Gene's organ in Argas walkerae.

Electron microscopy revealed that Gene's organ in females of Argas walkerae Kaiser & Hoogstraal (Ixodida: Argasidae) is formed as a double-sac structure consisting of an outer epithelial and an inner cuticular sac. The latter emerges through the camerostomal aperture to the exterior in ovipositing ticks. The epithelial sac forms the corpus and the two blind-ending horns, which pass into the epithelium of the excretory duct of a gland at each side of Gene's organ and envelop the cuticular sac. Both excretory ducts open into the lumen between the epithelial and the cuticular sac. The cuticular sac is folded and consists of a fibrous endocuticula outwards towards the lumen between the epithelial and the cuticular sac and of a smooth epicuticula inwards. Parallel running grooves occur over the lateral epicuticular surface turning medially into cobble-stone pavement-like rises. Tubuli pass through the cuticular sac ending in pores on the epicuticular surface and open into the lumen between the epithelial and the cuticular sac. Muscle fibres pass through the epithelial sac at the horn tips and are inserted to the cuticular sac. In ovipositing females, the glands are fully developed and the lumen between the epithelial and the cuticular sac is filled with an amorphous mass.

The mechanism of oviposition in Argas (Persicargas) walkerae (Acari: Argasidae).

The process of oviposition in A. walkerae was observed and found to be a sequence of exactly coordinated, interlocking events independent of the age of ticks. Egg-laying always commenced with numerous dorso-ventral movements of the capitulum. The pedipalps were spread during the last dorso-ventral movement and lowered to the ventral body wall embracing the genital aperture on both sides. Simultaneously, the cuticular sac of Gene's organ emerged and immediately everted maximally. Immediately afterwards the vestibulum vaginae prolapsed from the genital aperture touching the cuticular sac. The vestibulum vaginae handed over an egg to the cuticular sac after a brief contact. Then the vestibulum vaginae invaginated, the pedipalps closed and the cuticular sac was retracted. Finally, the capitulum very frequently moved up and down and the free egg was pushed in front of the ticks. The total time of laying an egg averaged 27 min in both 4-week-old and 12-month-old ticks. In 4-week and 12-month-old ticks, egg-laying was preceded by a mean preoviposition period of 6.1 days and 7.5 days, respectively, while the mean oviposition was completed in 14 and 10 days and the average egg totals were 119 and 103.

The Cox maze iii procedure: parallel normalization of sinus node dysfunction, improvement of atrial function, and recovery of the cardiac autonomic nervous system.

OBJECTIVE: The Cox maze III procedure includes isolation of the pulmonary veins and multiple incisions in both atria in what corresponds to partial autotransplantation and partial denervation of the heart. The aim of this prospective longitudinal study was to identify physiologic effects of reinnervation on changes in heart rate at rest and in response to various stimulations and on atrial function after the Cox maze III procedure. PATIENTS AND METHODS: Power spectral analysis of heart rate variability, exercise testing, 24-hour Holter monitoring, electrocardiography, and transthoracic and transesophageal echocardiography were performed in 30 adult patients after the combined Cox maze III procedure and mitral valve surgery (maze group). They were prospectively followed up at 1, 3, 6, and 12 months after the operation. The results were compared with those of 15 heart transplant recipients (transplant group) and normal probands (healthy adults, n = 12). RESULTS: The physiologic effects of denervation with no differences in cardiac autonomic activity between the groups were seen early after the operation. Later, evidence of autonomic reinnervation was observed only in the maze group but not in the transplant group. Inappropriate heart rate responses during physical exercise were clearly evident in both groups after 1 and 3 months, with progressive improvement seen between 6 and 12 months only in the maze group. Left atrial function after the Cox maze procedure improved parallel to the recovery of sinus node function. CONCLUSION: Progressive improvement of sinus node function and atrial contractions with significant functional normalization 1 year after the Cox maze procedure corresponded to functional reinnervation and recovery of the autonomic nervous system.

Identification of P waves after the Cox-maze procedure: significance of right precordial leads V3R through V6R.

BACKGROUND: The maze circuit lengthens the period of atrial depolarization and may lead to small or absent P waves, which may not be readily apparent in a standard 12-lead electrocardiogram. In this prospective study, we investigate if the right precordial leads V3R through V6R can improve detection of P waves and identification of atrial electrical activity. METHODS: Standard 12-lead electrocardiograms (with leads I through III, aVR, aVL, aVF, and V1 through V6) and right precordial electrocardiograms (V3R through V6R) were recorded in 30 consecutive patients during the first 5 postoperative days and 1, 3, 6, 12, and 24 months after combined Cox-maze III procedure and mitral valve surgery. The P wave identification as an indication of atrial electrical activity and atrial contraction was proved by transesophageal echocardiographic identification of atrial contractions. RESULTS: Despite echocardiographically identifiable atrial contractions, the P waves were not visible on standard 12-lead electrocardiograms in 7 (23%) patients after 1 and 3 months, and in 4 patients after 6 months. In contrast, right precordial electrocardiograms showed P waves in all of these patients that were best seen in lead V4R. Twelve and 24 months postoperatively, only 2 patients had no visible P waves in the standard leads that were still present in the right precordial leads. However, if P waves were easily identifiable in standard 12-lead electrocardiograms (23 patients at 1 and 3 months after surgery), the right precordial leads showed P waves only in 15 patients. CONCLUSIONS: Right precordial electrocardiogram with leads V3R through V6R is a helpful tool for visualizing P waves after the Cox-maze procedure. Standard 12-lead electrocardiogram should be combined with right precordial electrocardiogram in all patients after the Cox-maze procedure.

Transient sinus node dysfunction after the Cox-maze III procedure in patients with organic heart disease and chronic fixed atrial fibrillation.

OBJECTIVES: This prospective study examined types, frequency and time dependency of the electrophysiologic manifestation of the sinus node dysfunction after the Cox-maze III procedure--the technique of choice for the management of medically refractory atrial fibrillation-in patients with organic heart disease, chronic fixed atrial fibrillation and no preoperatively overt dysfunction of the sinus node. BACKGROUND: The original maze procedure was modified twice in order to reduce the high incidence of the sinus node inability to generate an appropriate sinus tachycardia in response to maximal exercise, and occasional left atrial dysfunction. Despite these modifications, postoperative disturbance of sinus node function can be frequently observed. METHODS: In 15 adult patients, standard electrocardiogram, 24-h Holter monitoring, power spectral analysis of heart variability, exercise testing, Valsalva maneuver and rapid positional changes were performed 3, 6 and 12 months after the Cox-maze III procedure and mitral valve surgery or closure of atrial septal defect. RESULTS: Electrocardiographic manifestations of sinus node dysfunction were identified in 12 patients at 3 months, in 6 patients at 6 months, and in 0 patients at 12 months after surgery. The heart rate response to exercise during the first 6 months was reduced in the maze group and became fully normal at 12 months. Power spectral analysis of heart rate variability showed very low power values at 1 month with inhibited cardiac autonomic activity and no response on sympathetic stress. A potential of recovery of cardiac autonomic activity was documented 12 months after surgery. CONCLUSIONS: The manifestations of sinus node dysfunction following the Cox-maze III procedure were time dependent and their frequency and intensity progressively decreased and disappeared within 12 months after surgery.

["Cox/Maze-III operation" as surgical therapy of chronic atrial fibrillation during mitral valve and atrial septal defect II operation]. / "Cox/Maze-III-Operation" als chirurgische Therapie des chronischen Vorhofflimmerns während Mitralklappen-und ASD-II-Operation.

PROBLEM: Atrial fibrillation is associated with significant morbidity and mortality. The increased risk of thromboembolism makes constant anti-coagulation necessary, while the absence of atrial contraction worsens the hemodynamic situation. In this study we examined the results of simultaneous surgical treatment of chronic atrial fibrillation through "Cox/Maze-III-procedure" while mitral valve surgery and atrial septal closure. PATIENTS AND METHODS: Between February 1995 and July 1997 sixteen patients aged 50 to 72 y (mean: 59 y) underwent open heart surgery (mitral valve replacement n = 10, reconstruction n = 3; mitral valve reconstruction and atrial septal closure n = 1, atrial septal closure n = 1, thrombectomy from left atrium n = 1) and "Cox/Maze-III-procedure" in one session. Preoperative duration of chronic atrial fibrillation was between 2 and 12 y (mean: 5.0 y). The patients were examined preoperatively and postoperatively 3, 6, 12, and 24 months after surgery using the following methods: transesophageal echocardiography (TEE), ECG, long-term ECG, and stress ergometry. RESULTS: During the early postoperative period (< 7 d) all of the patients were in sinus rhythm or atrial pacing; eight patients intermittently had atrial fibrillation. In the follow-up period from 1 to 27 months (mean 14 months), 15 patients have a stable sinus rhythm (94%). One patient, preoperatively known to have intermittent tachybradycardia, received a pacemaker 2 months postoperatively for sinus bradycardia. Postoperatively in TEE patients showed left atrial contraction with improvement of hemodynamic situation. Stress ergometry 6 months postoperatively showed lower increasements of heart rate, at 12 months normal frequency. CONCLUSION: The surgical treatment of chronic atrial fibrillation through "Cox/Maze-III-procedure" can be performed combined with other heart operations without increased perioperative or postoperative risks. The Maze-procedure is an effective surgical therapy of chronic atrial fibrillation. Postoperatively there is an improvement of the hemodynamic situation because of sinus rhythm and synchrone atrioventricular contraction.

[Surgical therapy of chronic atrial fibrillation with the "Cox/Maze-III-operation"]. / Chirurgische Therapie des chronischen Vorhofflimmerns mittels "Cox/Maze-III-Operation".

UNLABELLED: We examined the results of simultaneous surgical treatment of chronic atrial fibrillation using a Cox/Maze III operation during mitral valve surgery (n = 12), atrial secundum defect closure (n = 1), combined operation (mitral valve and atrial secundum; n = 1) and thrombectomy from the left atrium (n = 1). Mean preoperative atrial fibrillation was 5.1 years (range 0.5-12 years). In the mean follow-up period of 13.1 months (1-24 months), 14 patients (93%) had sinus rhythm. CONCLUSION: (1) The surgical treatment of chronic atrial fibrillation using a Cox/Maze III operation can be performed without increased perioperative or postoperative risks; (2) Cox/Maze III operation represents an effective surgical treatment of chronic atrial fibrillation.

Myocardial infarction and thrombolysis. Electrocardiographic short term and long term results using precordial mapping.

In a consecutive series of 56 patients with acute myocardial infarction, ST segment depression and elevation in the electrocardiographic limb leads I, II, and III were summated for each patient before and immediately after intracoronary streptokinase infusion and the results compared with the angiographic findings. Forty three patients had angiographically confirmed reperfusion of an initially occluded vessel and showed a significant decrease in summated ST shift. The ST segment changes in the limb leads virtually returned to normal in all 43 patients, and in most, inverted T waves developed. Thrombolysis was unsuccessful in 10 patients, and the infarct related coronary artery was already patent in three. When these two groups are combined, all 13 patients without reperfusion showed no significant change in summated ST segment shift. During percutaneous transluminal angioplasty inflation of the balloon in the vessel that was previously occluded simulated reocclusion and was followed by new ST elevation if the artery supplied viable myocardium. In a further consecutive study of 54 patients with anterior myocardial infarction, the precordial R waves and Q waves were studied over the four to six months following infarction using a standardised 48 electrode mapping system. All patients underwent a repeat angiogram after four to six months. In 36 patients the infarct related vessel was patent. They showed a significant mean increase in summated precordial R wave amplitude and a reduction in the mean number of precordial leads without R waves. In 18 patients with unsuccessful thrombolysis or reocclusion there was a further reduction in mean summated R wave amplitude and an increased number of precordial leads not showing R waves. Precordial R wave mapping seems to be a valuable non-invasive method of assessing the salvage of myocardium after reperfusion and the damage caused by reocclusion. Loss of R waves in the acute phase of myocardial infarction does not necessarily mean an irreversibly damaged myocardium.

[Electrocardiogram in acute anterior wall infarct after restoration of the blood supply]. / Das Elektrokardiogramm beim akuten Vorderwandinfarkt nach Wiederherstellung der Blutversorgung.

Changes in QRS complexes and ST-T segments were measured in 70 patients after acute anterior-wall myocardial infarction. Intracoronary streptokinase infusion was undertaken in the acute phase in 58 patients, 12 other patients treated conventionally without infusion serving as controls. Precordial ECG mapping employed 48 unipolar precordial leads. If recanalization of an occluded coronary artery was achieved, there was a significant rise in R amplitude (sum of R-wave amplitudes in the 48 leads) from 12.4 +/- 10.9 to 16.2 +/- 11.2 mV, within a period of up to four months after the acute stage. If thrombolysis failed or only conventional treatment had been practised, there was no rise in R-wave amplitude. Renewed occlusion of a vessel previously re-opened by streptokinase infusion produced a reduction in R-wave amplitude from 14.0 +/- 13.0 to 9.8 +/- 11.0 mV. The S-T segment elevation regressed immediately after recanalization of the coronary artery. The S-T segments were iso-electric after four months. Re-occlusion caused renewed S-T segment elevation up to monophasic form. Precordial ECG mapping is thus well suited for serial controls after various re-perfusion measures.