Biomedical subjects

J Hess

Publications and source records attributed to J Hess.

At least 19 recordsLinked to original sources

PubMed1992

Short- and midterm results of balloon valvuloplasty for valvular aortic stenosis in children.

During a 27-month period, 21 consecutive children (aged 0.1 to 15.7 years) with isolated valvular aortic stenosis underwent percutaneous transfemoral balloon valvuloplasty. Ten children had undergone earlier surgical valvulotomy. The indication for treatment was ST-T-segment changes at rest or during bicycle-ergometry, a continuous-wave Doppler-derived transvalvular gradient greater than 60 mm Hg or syncope, or a combination. Mean peak systolic left ventricular pressure decreased from 165 +/- 19 to 131 +/- 19 mm Hg (p less than 0.001). Mean end-diastolic left ventricular pressure did not change significantly (12 +/- 3 vs 11 +/- 5 mm Hg). Mean peak systolic valve gradient decreased from 71 +/- 23 to 22 +/- 11 mm Hg (p less than 0.001). Mean cardiac index remained unchanged (2.9 +/- 0.8 vs. 3.0 +/- 0.7 liters.min-1.m-2). Aortic valve regurgitation on angiography appeared or increased in 9 patients (up to grade 3 in 3 children). Noninvasive follow-up studies were performed for 2 to 4.2 years (mean 2.8). ST-T changes on the electrocardiogram at rest or during exercise were present in 6 patients before balloon valvuloplasty and had disappeared in all at 6-month follow-up. Reoccurrence of ST-T changes after a longer follow-up was associated with severe valve regurgitation. Syncope was not observed after balloon valvuloplasty. The continuous-wave Doppler gradient decreased from 94 +/- 36 to 49 +/- 15 mm Hg (p less than 0.001). After a follow-up of 2 to 4.2 years (mean 2.8) it remained unchanged (43 +/- 13 mm Hg; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Vasopressin and oxytocin in brain areas of rats selectively bred for differences in behavioral performance.

Wistar rats were selectively bred over 10 generations for differences in performance in a footshock-motivated brightness discrimination (BD) test in a Y-maze. High behavioral performance (Wis/HBP) and low behavioral performance (Wis/LBP) rat lines were obtained which differ significantly in all behavioral components tested: frequency of correct responses, number of trials to criterion, response latency (HBP less than LBP), and frequency of freezing behavior (HBP less than LBP), the latter suggesting differences in emotionality. In Wis/LBP rats, furthermore, the normal increase in behavioral performance between the training and the relearning session, which indicates the formation of a memory trace, disappeared during selection. In male breeders sampled during selection of the two lines (Wis/HBP: n = 17; Wis/LBP: n = 21), both arginine vasopressin (AVP) and oxytocin (OXT) contents were measured by radioimmunoassay in the motor cortex, septum/striatum, hippocampus, hypothalamus, medulla oblongata and posterior pituitary. Compared with the Wis/HBP rats, the Wis/LBP rats contained less AVP in the hippocampus (3.1 +/- 0.58 vs 8.3 +/- 1.4 pg/mg wet wt., mean +/- S.E.M., P less than 0.001), but more AVP in the medulla (1.7 +/- 0.20 vs 1.1 +/- 0.18 pg/mg, P less than 0.05). In contrast, no significant differences between the lines were detected with respect to OXT concentrations. In the Wis/LBP rats, moreover, the hippocampal AVP content decreased during selection (r = -0.645, P less than 0.01), while the acquisition response latency increased (r = 0.549, P less than 0.01). As a consequence, a significant, albeit weak, negative correlation (r = -0.483, P less than 0.05) was observed between the individual hippocampal AVP content and the response latency during acquisition. Thus, the results confirm the view that genetically determined differences in the hippocampal content of endogenous AVP may contribute to an individual's level of emotionality and behavioral performance.

Animals↗

PubMed1992

Processing by OmpT of fusion proteins carrying the HlyA transport signal during secretion by the Escherichia coli hemolysin transport system.

A fusion gene (ces-hlyAs) was constructed by ligating the genetic information for the C-terminal 60 amino acids (hlyAs) of Escherichia coli hemolysin (HlyA) to the ces gene for a cholesterol esterase/lipase (CE) from a Pseudomonas species. Part (about 30%) of the expressed fusion protein CE-HlyAs was secreted in E. coli carrying hlyB and hlyD genes. Following the insertion between the reporter gene and hlyAs of a linker sequence that contains the information for potential cleavage sites for the outer membrane protease OmpT, two different fusion proteins (PhoA-HlyAs and CE-HlyAs) were shown to be cleaved by OmpT between the two parts during HlyB/HlyD-mediated secretion. Processed PhoA and CE accumulated in the supernatant. The efficiency of cleavage by OmpT was considerably improved by increased ompT gene dose. It was further shown that OmpT preferentially recognizes potential cleavage sites within the linker sequence.

Amino Acid Sequence↗

PubMed1992

Biocompatibility of retrograde filling materials in the ferret canine. Amalgam and IRM.

Periapical tissue response to retrograde fillings of amalgam and IRM were compared in the mandibular canine of the adult male ferret. Teeth were cleaned and shaped with a standard technique and obturated with gutta-percha. The root apex was then exposed and retrofillings were placed. The animals were grouped according to observation periods of 5, 10, and 15 weeks. At the proper time the animals were killed and the lower canine tooth along with the surrounding bone was removed. The tissue blocks were examined clinically, radiographed, and prepared for histologic examination. The clinical and radiographic examination indicated both materials to be well tolerated by periapical tissues. Microscopic examination of amalgam specimens showed a decrease in inflammation and the formation of a fibrous capsule over the 15-week period. IRM specimens showed persistent inflammation and slower healing potential.

Alveolar Process↗

PubMed1992

Management of fixed subaortic stenosis: a retrospective study of 57 cases.

Although recommended by several investigators, the benefit of early surgery in patients with fixed subaortic stenosis has not been proved. Findings were reviewed of 57 patients with isolated fixed subaortic stenosis, including 27 surgically treated patients, with special emphasis on the occurrence of aortic regurgitation during a mean follow-up period of 6.7 years. The number of patients with aortic regurgitation increased preoperatively in the total group (23% at diagnosis to 54% after 3.7 years of follow-up). The prevalence of aortic regurgitation in the 27 surgically treated patients was higher (81%) than that in the nonsurgically treated group but remained unchanged after a mean postoperative period of 4.7 years. In all patients but one, aortic regurgitation remained of minor hemodynamic significance. One patient died during follow-up. After surgery, 15 patients (55%) showed a relapse; 11 redeveloped a subvalvular pressure gradient greater than 30 mm Hg and discrete subvalvular ridges (range 6 months to 24 years after surgery, mean 7 years). In those patients with fixed subaortic stenosis, follow-up did not reveal any benefit from early surgery. The unpredictable course and sometimes very severe progression of this disease make frequent and careful follow-up necessary.

Adolescent↗

PubMed1992

Transoesophageal echocardiographic evaluation of atrial morphology in children with congenital heart disease.

In a prospective study, atrial morphology was evaluated by both transoesophageal and precordial echocardiography in 86 unoperated children with congenital heart disease (age range = 0.2 to 14.8 years, mean = 3.8 years) to determine what advantages, if any, might be inherent in the transoesophageal approach. The information derived from both ultrasound approaches was correlated and compared to information obtained during subsequent cardiac catheterization (78 patients) and, or, surgical inspection (53 patients). Atrial appendage morphology and hence atrial situs was determined by transoesophageal echocardiography in every case (82 solitus, two right atrial isomerism, two left atrial isomerism). In addition, the transoesophageal approach indicated left juxtaposition in four patients, compared to only one by precordial examination. Probe patency of the foramen ovale was correctly predicted in 21 patients by transoesophageal imaging, but in only 10 by precordial imaging. In two children significant secundum defects, undetected by the precordial route, were identified. Multiple atrial septal defects were correctly defined in four patients by transoesophageal study but in only one by precordial study. Sinus venosus defects were documented in four by the transoesophageal approach, but in only one by the precordial. Primum defects were equally well documented (nine patients) by either technique, but the associated valve leaflet morphology was better documented by transoesophageal study in 5/9. A subtotal cor triatriatum was diagnosed in one child only by transoesophageal investigation. Transoesophageal echocardiography allows a much more detailed evaluation of atrial morphology than precordial imaging even in infants. It provides direct diagnosis of atrial situs, detection of juxtaposed atrial appendages and improved demonstration or definitive exclusion of atrial septal defects.

Adolescent↗

PubMed1992

Protrusion of the device: a complication of catheter closure of patent ductus arteriosus.

OBJECTIVE: To assess the medium term results of percutaneous transvenous closure of patent ductus arteriosus, in particular with regard to protrusion of the device with or without turbulence of the bloodflow. DESIGN: Clinical examination and echocardiographic study (cross sectional Doppler, and colour Doppler examination) within 24 hours of and at least 6 months after implantation (range 6-26 (mean 15) months). SETTING: Multicentre study at the departments of paediatric cardiology of three academic hospitals. Tertiary clinical care of the first group of patients in the Netherlands treated by the percutaneous transvenous method. PATIENTS: 36 patients (12 male, 24 female) mean age 8.2 years, (range 1.7-58.3), mean weight 25.5 kg (range 11-67.8 kg). The total group consisted of 46 patients. In one the implantation had failed and nine others were not available for regular follow up. All 36 patients underwent non-surgical closure of the patent ductus arteriosus with a Rashkind double umbrella prosthesis. MAIN OUTCOME MEASURES: Diagnosis or exclusion of protrusion of the Rashkind device with or without turbulence of the blood flow with follow up of changes in protrusion and turbulence. RESULTS: In 17 patients the prosthesis protruded into an arterial lumen: the aorta in 13 and the (left) pulmonary artery in four, with turbulence in seven and two cases respectively. After six months the aortic protrusion disappeared in three, including one who had had turbulent blood flow. At the end of follow up the prosthesis still protruded into the aorta in 10 but in three the turbulence had vanished. In two of the three remaining patients with turbulence in the descending aorta the degree of turbulence had decreased. There was no lessening of turbulence in the four patients in whom the device protruded into the pulmonary artery. CONCLUSIONS: The Rashkind double umbrella can protrude into the descending aorta and the left pulmonary artery without causing turbulent blood flow. Turbulence and the protrusion itself can disappear. Endocarditis prophylaxis may be required for as long as the device causes turbulence.

Adolescent↗

PubMed1992

Effects of X-linked hemoglobin on in-vitro platelet function.

The in-vitro function of platelets in 1:1 mixtures of fresh whole blood and 10% DBBF alpha-alpha cross-linked hemoglobin in Ringer's acetate buffer was assessed by quantitative aggregation after challenge with common agonists and compared to the function of platelets in similar dilutions of whole blood in saline. Whole blood aggregometry was performed after addition of ADP, collagen, and ristocetin. Aggregation was quantified by measuring the change in impedance as drawn on the chart recording. No difference in mean impedance change was noted between the groups of blood samples which were incubated and tested in the hemoglobin solution and those incubated and tested in saline. In addition, incubation and stirring of the above mixtures over a period of six minutes without the addition of agonists did not result in spontaneous platelet aggregation. We conclude that alpha-alpha cross-linked hemoglobin, in the concentration studied, does not affect in-vitro platelet function, as measured by whole blood aggregometry.

Aspirin↗

PubMed1992

A modification of staged septation for univentricular atrioventricular connection.

A case is reported in which is described a modification of staged septation for univentricular atrioventricular connection with double-inlet left ventricle and left-sided rudimentary outlet chamber beneath the aorta. This modification diminishes the risk of atrioventricular conduction disturbances by gluing the perforated septation patch on the myocardium in the area overlying the central conduction system. Fixation of the patch was facilitated by exact fitting of the patch in this area, by ample contact of the patch and the myocardium in this area, and by immobilization of the patch because of equal pressures on both sides because of the perforation of the patch. In addition, this modification facilitates evenly drawing in of the ventricular free wall because already, in the first stage, the complete circumference of the patch is fixed, defining the maximal contribution of prosthetic material to the newly created septum.

Double Outlet Right Ventricle↗

PubMed1991

Transesophageal echocardiographic monitoring of interventional cardiac catheterization in children.

Transesophageal echocardiography was used prospectively in 22 children scheduled for interventional cardiac catheterization (9 with pulmonary valvuloplasty, 5 with aortic valvuloplasty, 1 with pulmonary angioplasty, 2 with aortic angioplasty, 2 with patent ductus arteriosus occlusion and 3 with Mustard baffle dilation) to determine its potential value as a monitoring technique. The patients ranged in age from 0.9 to 14.6 years (mean 5.4) and in weight from 9.5 to 49.2 kg (mean 21.1). Studies were completed in all patients without complications. Preintervention studies provided important new information in two patients, leading to cancellation of the planned procedure. Major contributions of transesophageal monitoring included 1) a real time assessment of catheter placement across either atrioventricular valve and the aortic valve during balloon valvuloplasty; 2) immediate assessment of aortic valve and aortic wall morphology during balloon dilation; and 3) detailed morphologic and hemodynamic information together with enhanced catheter guidance during Mustard baffle dilation. After pulmonary valvuloplasty, partial chordal rupture of the tricuspid valve was documented in one patient. In two patients, balloon catheter position was modified according to the transesophageal findings. The assessment of changes in pulmonary valve morphology and transcatheter occlusion of a patent ductus arteriosus was not enhanced by single-plane transesophageal monitoring. Pulsed wave Doppler studies contributed additional information in the assessment of immediate hemodynamic changes after interventional procedures. Transesophageal echocardiography is a new important guiding and monitoring technique during interventional cardiac catheterization procedures in children. It can provide additional real time imaging information, immediate identification of complications and assessment of hemodynamic changes.

Adolescent↗

PubMed1991

The vasopressin receptor of the blood-brain barrier in the rat hippocampus is linked to calcium signalling.

The signal transduction system of the vasopressin receptor in cerebral microvessels is not known but appears not to be adenylate cyclase/cyclic AMP. We determined the effect of arginine vasopressin (AVP) on the intracellular free calcium concentration [Ca2+]i in endothelial cells of isolated hippocampal microvessels of rats, using the fura-2 fluorescence technique. AVP administration caused a rapid and transient rise of cytosolic free calcium which was absent after extracellular calcium was removed, and could be blocked with the vasopressin V1 receptor antagonist, d(CH2)5 Tyr(Me)AVP. The vasopressin V2 receptor agonist, 1-deamino-8,D-AVP, on the contrary, failed to affect the intracellular free calcium level, and was unable to inhibit the AVP-induced rise of [Ca2+]i in the preparation. Our results, therefore, demonstrate the presence of a calcium-signalling, i.e. V1 vasopressin receptor at the blood-brain barrier in the hippocampus of the rat.

Animals↗

PubMed1991

Surgery for Ebstein's anomaly: the clinical and echocardiographic evaluation of a new technique.

Ten consecutive patients (age range 4 to 44 years, mean 22) underwent surgical repair of Ebstein's anomaly by vertical plication of the right ventricle and reimplantation of the tricuspid valve leaflets. No patient died during or after operation. Intraoperative postbypass echocardiography documented a good result in nine patients but severe tricuspid regurgitation in one patient, who then underwent prosthetic valve replacement during a second period of cardiopulmonary bypass. Two of four patients who had had right ventricular papillary muscle dysfunction in the early postoperative period showed improved papillary muscle function with concomitant reduction of tricuspid regurgitation 6 months later. All patients were evaluated clinically and by echocardiography 2 to 23 months later. All patients showed clinical improvement, seven by one functional class and three by two classes. All were in sinus rhythm. The mean cardiothoracic ratio decreased by 6% (p less than 0.05). On bicycle ergometry performed in six patients, peak oxygen consumption exceeded 20 ml/kg per min in five. Tricuspid regurgitation diminished in eight patients (by three grades in two patients, by two grades in five and by one grade in one patient); it remained unchanged in two. Comparison of preoperative and postoperative pulsed Doppler flow velocities across the pulmonary valve showed an increase in the peak velocity of flow across the valve (mean 83 +/- 14 versus 97 +/- 11 cm/s, p less than 0.005) and a decrease in the time to peak velocity (mean 130 +/- 16 versus 91 +/- 23 ms, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1991

Aortic atresia with normal left ventricle: one-stage repair in early infancy.

Successful one-stage repair of aortic atresia with a left ventricle was performed in a 6-week-old infant using a new technique. After patch enhancement of the hypoplastic aortic arch, the transected proximal pulmonary artery was directly anastomosed to the aortic arch. An intraventricular baffle established continuity between the left ventricle and neoaortic valve, and a homograft conduit was inserted between the right ventricle and pulmonary artery bifurcation.

Anastomosis, Surgical↗

PubMed1991

Transesophageal echocardiography in evaluation and management after a Fontan procedure.

Transesophageal echocardiography was used in 18 patients (aged 1.6 to 34 years, mean age 12.6) to assess the immediate (5 patients) or intermediate (13 patients) results after a Fontan-type procedure. The findings were correlated with precordial echocardiographic (all patients) and cardiac catheterization (11 patients) data. Atrial shunting was documented by transesophageal studies in three patients (precordial in one patient). In two patients it was confirmed by cardiac catheterization; the third underwent reoperation based on the transesophageal study alone. Pulmonary artery obstruction was documented in three patients (precordial in one patient) and was confirmed by subsequent cardiac catheterization in all. Evaluation of anterior Fontan connections was successful in 5 of 8 patients (precordial in 6 of 8), and posterior connections in 10 of 10 patients (precordial in 5 of 10). A Glenn shunt could be evaluated in eight of nine patients (precordial in three of nine). Thrombus formation was detected by transesophageal studies in three patients (precordial in one patient); repeat studies were used to evaluate thrombolytic therapy in two. Atrioventricular valvular regurgitation (11 of 18 patients) was better defined by transesophageal than by precordial studies (5 of 18). A coronary artery fistula was identified in two cases (precordial in none). Transesophageal pulsed Doppler interrogation of pulmonary artery and pulmonary vein flow patterns consistently allowed a detailed evaluation of the Fontan circulation. Transesophageal echocardiography is an important diagnostic and monitoring technique after the Fontan procedure. In this series, it was far superior to precordial ultrasound evaluation and of substantial additional value to cardiac catheterization.

Adolescent↗

PubMed1991

One stage repair of aortic arch anomalies and intracardiac defects.

Between August 1985 and May 1990, 27 neonates and infants underwent combined correction of intracardiac and aortic arch anomalies through a median sternotomy. Coarctation (CoA) was combined with VSD (6), AVSD (2), Taussig-Bing (TB) heart (5), transposition of the great arteries (TGA) (1), TGA + VSD (2), congenitally corrected TGA + VSD (1) and VSD + myxoid stenotic outlet valves (1). Interrupted aortic arch (IAA) was combined with VSD (10) and TB heart (1). Two patients had IAA type B as well as CoA. Age at operation varied from 2 to 243 days with a mean age of 51 days. Twenty patients (70%) were younger than 30 days. One TGA + VSD and all TB hearts had maligned outlet septum and right ventricular outflow tract obstruction (RVOTO). Posterior outlet septum deviation and left ventricular outflow tract obstruction (LVOTO) occurred in 8 patients with malalignment VSD and IAA (7) or CoA (1). Aortic arch reconstruction was performed using extended end-to-end anastomoses. In 3 patients, arch hypoplasia necessitated patch implantation. VSDs were closed through the right atrium unless the anatomy dictated otherwise. One TB heart was reconstructed with a Kawashima procedure. All other TB hearts and all TGAs were corrected with arterial switch operation. Obstructing outlet septum was resected whenever necessary. Follow-up was complete and included echo-Doppler control. Eleven patients had postoperative heart catheterisation. Early mortality was 18.5% (5 patients). Persisting LVOTO or RVOTO was responsible. There was no late mortality. Five patients were reoperated upon: 3 for stenotic anastomoses and 2 for a subaortic membranous stenosis. Successful balloon dilatation of recoarctation was performed four times.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

PubMed1991

The role of transoesophageal echocardiography in adolescents and adults with congenital heart defects.

Between April 1985 and December 1989, outpatient transoesophageal echocardiography was performed in 133 adolescent and adult patients (14% of all outpatient transoesophageal studies) (age range 11-78 years; weight 30-95 kg) to determine the value of this technique both in establishing the primary diagnosis (62 patients) and in the post-surgical follow up (71 patients) of congenital heart disease. The results were correlated with the findings of precordial echocardiography, catheterization and surgical inspection. Clear advantages of transoesophageal imaging over precordial imaging include: (1) direct identification of atrial appendage morphology in all patients; (2) delineation of systemic and pulmonary venous connections; (3) atrial baffle function (eight patients); (4) better evaluation of the Fontan-type circulation (five patients); (5) improved morphologic assessment of the atrioventricular junction and valves (29 patients); (6) definition of subaortic obstruction (18 patients); and (7) definition of ascending aortic morphology in Marfan's syndrome and supravalvar aortic stenosis (13 patients). The problems encountered with transoesophageal imaging include: (1) limited imaging planes; (2) poor visualization of specific intracardiac regions (antero-apical trabecular septum, right ventricular outflow tract); (3) flow masking behind implanted intracardiac prosthetic material.

Adolescent↗

PubMed1991

Role of intraoperative ultrasound examination in patients undergoing a Fontan-type procedure.

To determine its potential impact on perioperative surgical management intraoperative ultrasound examination (cross sectional imaging, colour flow mapping, pulsed and continuous wave Doppler) was used in 16 consecutive patients undergoing a Fontan-type procedure. Epicardial cross sectional imaging before bypass defined the precise intracardiac morphology in 15 of 16 patients. The preoperative morphological diagnosis was refined in four patients (25%), and this influenced surgical management in two (12%). Epicardial studies after bypass identified seven residual haemodynamic lesions in five patients (three residual intercardiac shunts, one ventricular outflow obstruction, one pulmonary artery obstruction, two mitral valve regurgitation), and led to immediate revision during a second period of bypass in three (18%). In one patient who required early reoperation residual shunting was not detected after bypass by either colour flow mapping or a contrast study. Final intraoperative studies showed a good surgical result in 14 patients (87%). Flow characteristics and flow velocities within the Fontan circulation could be assessed immediately after the patient came off cardiopulmonary bypass by means of combined pulsed wave Doppler and colour flow mapping in 14 of the 16 patients. Cross sectional studies of the left heart after bypass showed no change in ventricular function and allowed monitoring of volume replacement and ventricular filling. Intraoperative ultrasound was a valuable monitoring technique in patients undergoing a Fontan-type procedure. It refined preoperative diagnosis, monitored ventricular function, and identified or excluded residual haemodynamic lesions in most patients.

Adult↗

PubMed1991

Assessment of anomalous systemic and pulmonary venous connections by transoesophageal echocardiography in infants and children.

OBJECTIVE: To assess the value of transoesophageal echocardiography in the preoperative definition of systemic and pulmonary venous connections. DESIGN: Transoesophageal echocardiographic studies were performed prospectively under general anaesthesia in 76 consecutive unoperated children. Results were compared with those obtained by earlier transthoracic ultrasound studies (n = 76), cardiac catheterisation (n = 62), and subsequent surgical inspection (n = 58). SETTING: Two tertiary referral centres. PATIENTS: 76 unoperated infants and children (age 0.2-14.8 years, mean age 4.1 years) with congenital heart disease. MAIN OUTCOME MEASURE: Identification of anomalous systemic and pulmonary venous connections. RESULTS: Transoesophageal studies showed anomalous venous connections in 14 patients. Two had both anomalous systemic and pulmonary venous connections. Transoesophageal studies showed 12 anomalous systemic venous connections in nine patients. In eight patients these were confirmed at operation or catheterisation: one patient is awaiting operation. Six anomalous systemic venous connections were missed during earlier transthoracic studies. Anomalous pulmonary venous connections (one mixed total, six partial) were shown in seven patients. These were confirmed at operation in six and by cardiac catheterisation in one. Four of these patients were missed during earlier transthoracic ultrasound studies. No patient defined as having normal venous connections by the transoesophageal study was subsequently shown to have anomalous venous connections at operation or angiography. CONCLUSIONS: Transoesophageal echocardiography is a highly sensitive tool for the preoperative definition of systemic and pulmonary venous connections. In this series it was better than transthoracic ultrasound and complemented cardiac catheterisation and angiocardiography.

Adolescent↗