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Biomedical subjects

C Hasse

Publications and source records attributed to C Hasse.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Results of a standardized treatment concept in primary hyperparathyroidism].

BACKGROUND AND OBJECTIVE: Primary hyperparathyroidism (PHPT) is being diagnosed ever more frequently. After diabetes mellitus, ovarian dysfunction and metabolic disorders it is now among the most frequent metabolic disease. Its surgical treatment has become standardized with increasing experience. A prospective study was undertaken to clarify to what extent our own standardized diagnostic and therapeutic measures conform to current standards in literature. PATIENTS AND METHODS: During 10 years (1. 1. 1987-31. 12. 1996) 478 patients with PHPT were treated surgically (solitary adenoma: 317 (76.5%), multiple lobe hyperplasias 66 (15.9%), double adenoma 28 (6.8%), and carcinoma 4 (0.8%). PHPT was part of the MEN (multiple endocrine neoplasia) syndrome in 20 patients. Typical symptoms of PHPT had been present in 400 patients (83.7%), while 78 (16.3%) had no manifest symptoms. Ultrasound examination of the soft tissues was the only preoperative test of localization. More extensive preoperative diagnosis was practised only before reoperations. All patients had bilateral exploration of the neck to try and demonstrate all four epithelial bodies. RESULTS: A primary operation normalized the calcium level in 405 of 414 patients (97.8%). In 64 previously unsuccessfully operated patients who were reoperated for persisting HPT the elevated calcium levels could be normalized in 90.6%. Hypercalcaemia was finally abolished in all 478 patients. Average follow-up duration for 319 patients was more than 4.8 (0.5-8.5) years. The perioperative mortality rate was 0.8 (4 of 478), with 41 deaths during the later follow-up period. Permanent recurrent laryngeal nerve palsy occurred in 6 patients (1.8%). Long-term calcium substitution was necessary postoperatively in four patients (1.2%). CONCLUSION: Our findings support a liberal policy towards indication for bilateral surgical exploration of the neck in PHPT.

Adenoma↗
PubMed1997

A prospective evaluation of catheter ablation of ventricular tachycardia as adjuvant therapy in patients with coronary artery disease and an implantable cardioverter-defibrillator.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) therapy is integral to current therapy for ventricular tachycardia. Patients with an ICD frequently require concomitant antiarrhythmic drug therapy. Despite this, some patients still receive frequent ICD therapies for ventricular tachycardia. Therefore, the purpose of this prospective study was to determine the utility of ablation of ventricular tachycardia in patients with an ICD who experience frequent ICD therapies. METHODS AND RESULTS: Twenty-one consecutive patients with frequent ICD therapies despite antiarrhythmic drug therapy were the subjects of this study. The mean age was 69+/-6 years, and 17 were men. The mean ejection fraction was 0.22+/-0.08, and all patients had coronary artery disease. During the 36+/-51 days (range, 4 days to 7 months) preceding the ablation procedures, the patients received 34+/-55 ICD therapies for the clinical ventricular tachycardia, or a mean of 25+/-88 ICD therapies per month. The patients underwent radiofrequency ablation of the presumed clinical ventricular tachycardia by inducing the tachycardia and mapping according to endocardial activation, continuous electrical activity, pace mapping, concealed entrainment, or mid-diastolic potentials. Ablation of the clinical arrhythmia was successful in 76% of patients during 1.4+/-0.6 (range, 1 to 3) ablation procedures and required 12.5+/-9.2 applications of energy. During 11.8+/-10.0 months of follow-up, the frequency of ICD therapies per month decreased from 60+/-80 before successful ablation to 0.1+/-0.3 ICD therapies per month after ablation (P=.01). A quality-of-life assessment demonstrated a significant improvement after successful (P=.02) but not unsuccessful ablation (P=.9). CONCLUSIONS: Radiofrequency ablation of ventricular tachycardia as adjuvant therapy in patients with coronary artery disease and an ICD has a reasonable success rate, significantly reduces ICD therapies, and appears to be associated with an improved quality of life.

Aged↗
PubMed1997

Susceptibility of mononuclear phagocytes to influenza A virus infection and possible role in the antiviral response.

Among leukocytes, only monocytes and macrophages were found to be highly susceptible to an infection by influenza A virus. After infection, de novo viral protein synthesis was initiated but then interrupted after 4-6 h. Most macrophages died by apoptosis within 25-30 h. Before cell death, however, macrophages responded to influenza A virus with a high cytokine gene transcription and subsequent release of tumor necrosis factor alpha (TNF-alpha), interleukin-1 (IL-1), IL-6, interferon (IFN)-alpha/beta, and CC-chemokines. The basic mechanisms of virus-induced cytokine expression are still unknown and appear to involve transcription factors such as nuclear factor-kappaB and AP-1 which, however, were only activated for 2 h and declined below control values thereafter. After influenza A virus infection, only the mononuclear cell attracting CC-chemokines macrophage inflammatory protein 1alpha (MIP-1alpha), MIP-1beta, and RANTES were produced while the prototype neutrophil CXC-chemoattractants IL-8 and GRO-alpha were entirely suppressed. This selective induction of CC-chemokines may explain the preferential influx of mononuclear leukocytes into virus-infected tissue. Our data show that monocytes and macrophages represent a primary target for an influenza A virus infection. Thus, the mononuclear phagocyte response leads to a rapid proinflammatory reaction and an enhanced immigration of mononuclear leukocytes, which may condition the infected host for the subsequent virus antigen-specific defense.

Apoptosis↗
PubMed1997

Platelet serotonin and interleukin-1 beta after sleep deprivation and recovery sleep in humans.

Sleep deprivation (SD) represents a well-established therapy for major depression. Recent findings suggest that the antidepressive effects of sleep deprivation are mediated at least in part by pro-serotoninergic mechanisms. Furthermore, SD has been demonstrated to modify different host defense activities. We therefore investigated the serotonin (5-HT) content in platelets, platelet density distribution and 5-HT-induced IL-1 beta release from platelets in 10 healthy men before and after total SD (TSD) as well as after recovery sleep. Blood samples were drawn on 3 consecutive days at 7.00 h, 13.00 h, and 19.00 h, respectively. In addition, the psychophysiological parameters tiredness and wakefulness were assessed. After TSD the normal daily variation of IL-1 beta release with high morning levels and low evening levels was found to be significantly inverted. The release of IL-1 beta corresponded positively to the subjectively experienced tiredness of the probands. Analysis of platelet density distribution indicated a significant daily variation of low density platelets with low levels in the morning and high levels in the evening, which was absent after TSD. Our findings favour an increased pro-serotoninergic effect after TSD, which comprises respective variations of the host defense system, but is abolished by consecutive recovery sleep.

Adult↗
PubMed1997

"Surgical" ultrasound in suspected acute appendicitis.

BACKGROUND: Ultrasonography (US) by acknowledged experts enhances the diagnostic performance and reduces the rate of negative laparotomies in patients with suspected acute appendicitis (AA). METHODS: The diagnostic accuracy and clinical impact of routine US performed by surgical residents was prospectively studied in 504 unselected patients admitted for AA. Clinical and US findings were correlated with laparotomy findings and pathological outcome in 135 patients (113 cases with proven AA, prevalence 22.4%) and clinical as well as follow-up data were compared in the remainder. RESULTS: The overall accuracy, sensitivity, and specificity of the clinical diagnosis of AA were 84.9%, 51.3%, and 94.6% and those of US were 93. 6%, 83.1%, and 96.6%. Joint evaluation of the results from clinical evaluation and US further improved diagnostic performance (accuracy 93.4%, sensitivity 84.1%, specificity 96.2) and significantly reduced the rate of diagnostic errors to 3.4% (p < 0.001) and unnecessary laparotomies to 9.6% (p < 0.01) in patients with suspected AA. CONCLUSIONS: Ultrasonographic evaluation of the patient with suspected AA is considered to be of value in surgical practice.

Acute Disease↗
PubMed1997

Diagnostic ultrasound of acute colonic diverticulitis by surgical residents.

BACKGROUND: Recent studies have documented the feasibility of ultrasonography (US) to diagnose acute colonic diverticulitis (ACD). This prospective observational trial determined the sonomorphology of ACD and evaluated the diagnostic accuracy of routine US performed on admission by surgeons in training. METHODS: Fifty-seven consecutive patients with a confirmed episode of ACD were entered into this study, and the sonomorphology of the involved colon was assessed. US findings were compared to the results of the clinical evaluation and correlated to the clinicopathological outcome. RESULTS: The sonomorphology of ACD was characterized by segmental inflammatory transformation of the colon averaging 9.9 +/- 3.2 cm (range, 6-20) in length and visualized as target phenomena of a mean 3.5 +/- 0.8 cm (range, 2.4-4.8) width. Targets were caused by hypoechogenic thickening of the colonic wall of an average 7.7 +/- 2. 6 mm (range, 4-18). In 40% of cases, a hyperechogenic halo representing peridiverticulitis (average width, 2.3 +/- 0.6; range, 1.2-3 cm) was noted. Diverticula were seen in almost half of the cases. Of the 57 cases with confirmed ACD, the diagnosis was made by US in 48, for a global accuracy of 84.2%. US was false negative in nine patients, suggesting perforated appendicitis in five cases and acute appendicitis in one (the final diagnoses were perforated sigmoid diverticulitis in five cases and cecal diverticulitis in one case). In three patients, US was nondiagnostic. CONCLUSION: In the hands of sonographically trained surgeons, ultrasound is a useful modality to image acute colonic diverticulitis. US reveals diagnostic sonomorphology in most cases of ACD and therefore facilitates early confirmation of the diagnosis and assessment of severity.

Acute Disease↗
PubMed1997

Octreotide: effective treatment for hyperparathyroidism? A prospective, randomized, controlled clinical trial.

BACKGROUND: Recent studies suggest a role for somatostatin in the medical treatment of hyperparathyroidism. In a prospective, randomized, controlled, triple blinded clinical trial in patients with primary or secondary hyperparathyroidism, we evaluated the response of biochemical parameters relevant in hyperparathyroidism to the somatostatin analog octreotide. METHODS: Forty patients each with primary or secondary hyperparathyroidism were studied. Among other parameters, serum calcium and serum phosphate, parathyroid hormone, calcitonin, osteocalcin, and octreotide were assessed before and repeatedly for 4 hours after a single intravenous application of 200 micrograms octreotide or placebo. Subsequent to operation, which was performed on all patients, somatostatin-receptor autoradiography of parathyroid tissue was performed. RESULTS: After administration of octreotide, which resulted in an increase of plasma levels to pharmacologic levels, no significant changes in any of the biochemical parameters investigated for were observed. Multivariate analysis did not identify patient subpopulations that responded to either drug or placebo (p > 0.05). Forty-five percent of patients receiving octreotide reported side effects: Parathyroid tissue samples of patients with primary or secondary hyperparathyroidism were negative for somatostatin-receptor expression. CONCLUSIONS: Octreotide has no discernible effect on biochemical parameters of patients with primary or secondary hyperparathyroidism. Absence of somatostatin receptors, together with lack of octreotide effects, suggests that somatostatin is not effective in the medical therapy of hyperparathyroidism.

Adolescent↗
PubMed1997

Long-term follow-up after radiofrequency modification of the atrioventricular node in patients with atrial fibrillation.

OBJECTIVES: The purpose of this study was to describe the long-term follow-up results in 62 patients with atrial fibrillation and an uncontrolled ventricular rate, who underwent radiofrequency modification of the atrioventricular (AV) node. BACKGROUND: Previous studies in small numbers of patients have suggested that radiofrequency modification may be effective in controlling the ventricular rate in patients with atrial fibrillation, but long-term follow-up data have been lacking. METHODS: The subjects of this study were 62 consecutive patients (mean age +/- SD 65 +/- 14 years; 43 with structural heart disease) who underwent an attempt at radiofrequency modification of the AV node because of symptomatic, drug-refractory atrial fibrillation with an uncontrolled ventricular rate. The atrial fibrillation was chronic in 46 patients and paroxysmal in 16. Radiofrequency energy was applied to the posteroseptal or mid-septal right atrium to lower the ventricular rate in atrial fibrillation to 120 to 130 beats/min during an infusion of 4 micrograms/min of isoproterenol. RESULTS: Short-term control of the ventricular rate was successfully achieved without the induction of pathologic AV block in 50 (81%) of 62 patients. Inadvertent high degree AV block occurred in 10 (16%) of 62 patients, with the AV block occurring at the time of the procedure in 6 patients and 36 to 72 h after the procedure in 4. During 19 +/- 8 months of follow-up (range 4 to 33), 5 (10%) of 50 patients had a symptomatic recurrence of an uncontrolled rate during atrial fibrillation. Overall, adequate rate control at rest and during exertion, without pathologic AV block, was achieved long term in 45 (73%) of 62 patients. Among 37 patients with a successful outcome, left ventricular ejection fraction increased from (mean +/- SD) 0.44 +/- 0.14 to 0.51 +/- 0.10 one year later (p < 0.001). Complications other than AV block included polymorphic ventricular tachycardia 10 to 24 h after the procedure in two patients who had a predisposing factor for ventricular tachycardia and sudden death 1 to 5 months after the procedure in two patients with idiopathic dilated cardiomyopathy, one of whom had a pacemaker for AV block. CONCLUSIONS: In approximately 70% of properly selected patients with atrial fibrillation and an uncontrolled ventricular rate, radiofrequency modification of the AV node results in excellent long-term control of the ventricular rate at rest and during exertion.

Aged↗
PubMed1997

Isotransplantation of microencapsulated parathyroid tissue in rats.

Permanent hypoparathyroidism is one of the most difficult of all endocrine disorders to treat medically. While autotransplantation of parathyroid tissue is clinically established, allotransplantation without immunosuppression is still at the level of animal experiments. Although persons affected by hypoparathyroidism are facing a clearly reduced quality of life, hypoparathyroidism rarely is a life threatening condition. Therefore, systemic immunosuppression for recipients of allotransplants is not justified. A conceptional alternative would be protecting the tissue to be transplanted from the immunologic response by coating it with a semipermeable membrane (microencapsulation). In 1994, we succeeded in iso-, allo- and xenotransplantation of microencapsulated parathyroid tissue in an animal model. Unfortunately, prior to the first clinical use, further analysis of the coating substance (alginate) demonstrated that it has mitogenic properties. Here, we report on the first successful transplantation of microencapsulated parathyroid tissue using a purified, non-mitogenic alginate which is suitable for clinical use.

Animals↗
PubMed1997

Prospective evaluation of ultrasonography in acute colonic diverticulitis.

BACKGROUND: The clinical diagnosis of acute colonic diverticulitis (ACD) can be difficult and ultrasonography by experts is valuable in establishing the diagnosis. This prospective observational trial aimed to assess the diagnostic accuracy and clinical value of ultrasonography performed routinely by surgical residents in training. METHODS: The clinical course of 187 unselected consecutive patients admitted with suspected ACD was studied prospectively. Patients who had surgery for generalized peritonitis were excluded, leaving 143 for evaluation. Ultrasonographic findings and clinical assessment on admission were correlated with the patient's clinicopathological data and discharge diagnosis respectively. RESULTS: Of 74 patients with proven ACD (prevalence 52 per cent) the diagnosis was made by ultrasonography in 62, with an accuracy of 88 per cent, sensitivity 84 per cent and specificity 93 per cent. Ultrasonography gave a false-negative result in 12 patients (negative predictive value (NPV) 84 per cent) and there were five false-positive findings (positive predictive value (PPV) 93 per cent). The final diagnosis in the latter five patients was colitis (two patients), caecal carcinoma (one), colonic ileus due to perforated sigmoid carcinoma (one) and suppurative pyosalpingitis with involvement of the sigmoid colon (one). The accuracy of clinical evaluation on admission was 71 per cent (sensitivity 82 per cent, specificity 55 per cent, PPV 72 per cent, NPV 68 per cent); however, in only 53 per cent of patients was the diagnosis considered clinically unequivocal. CONCLUSION: Ultrasonography is a useful and valid modality for imaging ACD and its differential diagnoses in the hands of sonographically trained surgeons. It is especially helpful when the clinical findings are equivocal.

Acute Disease↗
PubMed1996

The mechanisms responsible for lack of reproducible induction of atrioventricular nodal reentrant tachycardia.

INTRODUCTION: AV nodal reentrant tachycardia (AVNRT) is not always reproducibly inducible. The purpose of this study was to determine the mechanisms responsible for the lack of reproducible induction of AVNRT. METHODS AND RESULTS: The induction of AVNRT was assessed with atrial burst pacing, and with atrial and ventricular programmed stimulation, each with one and two extrastimuli, in 103 patients with AVNRT. The stimulation protocol was repeated 10 times in the baseline state, during isoproterenol infusion, and after atropine administration, or until AVNRT was induced in 7 of 10 attempts. The mechanisms responsible for < 7 of 10 inductions were classified as: (1) the inability to achieve critical AH prolongation; (2) fast pathway block; and (3) slow pathway block. The induction endpoint was achieved in 90 patients: 55 in the baseline state, 34 during isoproterenol infusion, and 1 after atropine. The mechanism of noninducibility in the baseline state (n = 48) was the inability to achieve a critical AH interval in 20%, fast pathway block in 49%, and slow pathway block in 31% (P = 0.02). During isoproterenol administration (n = 14) and after atropine administration (n = 13), the three mechanisms were equally responsible for nonreproducible induction of AVNRT. CONCLUSIONS: The induction of AVNRT is poorly reproducible in approximately 10% of patients. In the baseline state, the most common reason for the inability to reproducibly induce AVNRT is fast pathway block. In the presence of isoproterenol or atropine, each of the three mechanisms was equally responsible for noninducibility of AVNRT.

Adrenergic beta-Agonists↗
PubMed1996

Osseointegrated implants in patients treated for generalized severe adult periodontitis. An interim report.

This study presents oral rehabilitation with osseointegrated implants in partially edentulous patients treated for generalized severe adult periodontitis. Five female patients aged between 31 and 44 received a total of 36 implants and were observed for 1 year after insertion of the superstructure. Three months before implantation, venous blood samples were taken from the patients and five periodontally healthy controls, and the serum examined with highly sensitive ELISA test kits for interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6). Clinical examination covered the plaque index (PI) and gingival index (GI) at teeth and implants plus probing depth (PD) and clinical attachment level (CAL) at the teeth. Microbiological evaluation of teeth and implants was performed by dark-field analysis, and DNA analysis was performed in addition 1 year after insertion of the superstructure. Radiological controls of the teeth were carried out with standard single-tooth films in the 2 years preceding implantation and at baseline. Following implantation, further controls of the teeth and implants were undertaken immediately after insertion of the superstructure and 1 year thereafter. The immunological examination revealed that the IL-1 beta (0.22 +/- 0.2 pg/ml) (means +/- SD) and IL-6 (2.27 +/- 2.8 pg/ml) level was slightly, but not significantly, higher in the patients than in the control group (IL-1 beta: 0.06 +/- 0.06 pg/ml and IL-6: 0.64 +/- 0.2 pg/ml) (P > 0.05). The clinical results show that the GI at the teeth rose slightly from 0.0 to 0.2, and at the implants from 0.3 to 0.4. The PI rose slightly from 0.3 to 0.7 at the teeth and from 0.2 to 0.9 at the implants. Neither the GI nor the PI revealed any significant difference between teeth and implants. Clinical attachment loss at the teeth was minimal at 4.7 to 4.8 mm. Comparison between the teeth and the implants revealed no essential difference in bacterial flora; neither Actinobacillus actinomycetemcomitans nor Porphyromonas gingivalis was recorded at any location. Small quantities of Prevotella intermedia were detected at the teeth and implants of one patient. Radiological evaluation 1 year after insertion of the superstructure revealed a mean bone loss of 0.62 mm at the implants. The bone loss at the teeth during the same period was 0.3%, whereas it had been 1.5% in each of the 2 previous years. These results suggest that there is only a slight difference between the periodontal and peri-implant areas in patients with generalized severe adult periodontitis. The full potential for implants in these patients, however, needs to be shown in controlled longitudinal studies.

Adult↗
PubMed1996

Transplantation of parathyroid tissue in experimental hypoparathyroidism: in vitro and in vivo function of parathyroid tissue microencapsulated with a novel amitogenic alginate.

Microencapsulation of tissues is an alternative to postoperative immunosuppression in transplantation. In 1994 iso-, allo- and xenotransplantation of microencapsulated parathyroid tissue was achieved in vivo. However, continued analysis of the coating substance (an alginate) determined mitogenic properties. Here, we report on the in vitro and in vivo function of parathyroid tissue microencapsulated with a novel amitogenic alginate suitable for use in humans. To assess in vitro function, parathyroid tissue encapsulated with mitogenic and amitogenic alginate was exposed to rising concentrations of calcium. For in vivo experiments, it was isotransplanted into parathyroidectomized rats. PTH release into medium and PTH serum levels as well as calcium levels of recipient rats were analyzed and compared to native (non-microencapsulated) tissue and empty capsules, respectively. In vivo, transplants were excised and subjected to histologic examination six months after trans-plantation. In vitro, parathyroid tissue encapsulated with amitogenic alginate releases approximately half of the PTH of the native tissue, not different from tissue encapsulated with the mitogenic alginate. In vivo, the novel alginate preserved parathyroid function similar to that of native tissue over the six month period resulting in complete reversal of hypoparathyroidism. Correspondingly, histologic examination revealed vital parathyroid tissue in intact microcapsules. By establishing in vitro function and successful long-term transplantation, we have documented the principle of microencapsulation of parathyroid tissue to be effective also with the novel amitogenic alginate, which is suitable for clinical use.

Alginates↗
PubMed1995

Clinical and surgical aspects of double adenoma in patients with primary hyperparathyroidism.

The incidence of double parathyroid adenoma in 277 prospectively documented patients suffering from primary hyperparathyroidism was 5.4 per cent (15 patients). Patients with double adenoma were all symptomatic and had a significantly higher parathyroid hormone (PTH) level and tumour weight than those with a solitary adenoma or four-gland hyperplasia. In 11 patients the adenomas were located bilaterally. Bilateral neck exploration must be performed routinely to deal successfully with this condition at initial operation. In six patients one enlarged gland was found in the thymus or posterior mediastinum. These locations should be explored, especially in patients with high PTH levels, in those in whom all four parathyroid glands cannot be detected or if only one small adenoma is found. In all such patients, selective resection of the enlarged parathyroid glands resulted in normocalcaemia (median follow-up 3.5 years). Selective resection of the pathological glands is the treatment of choice.

Adenoma↗