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Biomedical subjects

J Tacke

Publications and source records attributed to J Tacke.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Experimental model of early chronic pelvic vein thrombosis with occlusion spirals and thrombin].

PURPOSE: To create an early chronic venous thrombosis with good comparability to human venous thrombosis for evaluation of new thrombectomy systems. METHODS: Using a transjugular approach, three dacron-fibered occlusion coils were placed into the proximal common iliac vein of 7 pigs under general anesthesia. The coiled common iliac vein was blocked by the use of a balloon occlusion catheter, and 500 units of thrombin were injected into the "coil basket". One hour later, the balloon catheter was deflated and removed. After three days, the thrombus was controlled by phlebography and histology. RESULTS: The induction of thrombi was successful in all cases. The mean length of the thrombi was 60 mm and the mean diameter was 10 mm. Histologically, the thrombus consisted of a laminated plug of fibrin and platelets as well as clots in the sense of a mixed thrombus with signs of a beginning organization. Considering the cellular composition and the histological aspect, the thrombi met the criteria for early chronic venous thrombosis in humans. CONCLUSION: The presented experimental thrombus model is easy to perform and enables a good comparability to early chronic human venous thrombosis.

Animals↗
PubMed1998

Cost-effectiveness of primary and secondary prevention in cardiovascular diseases.

UNLABELLED: INTRODUCTION, AIMS, AND METHODS: Industrial countries' societies are challenged to counter the increasing costs of health care. The preponderance of cardiovascular diseases in middle-aged people demands new strategies to reduce the extremely high rates of early deaths and increased morbidity and thus to avert considerable costs. Prevention programmes are appropriate means to combine therapeutic needs with health economic goals. A review of techniques of economic evaluation is given, from which a critical appraisal of cost-effectiveness analyses in primary and secondary prevention with HMG-CoA reductase inhibitors in coronary heart disease follows. Our own analysis of cost-effectiveness of primary prevention based on the clinical results of the WOSCOP study is also presented. RESULTS AND CONCLUSIONS: Long-term treatment with HMG-CoA reductase inhibitors is effective (30% mortality reduction), safe and tolerable. With a cost-effectiveness ratio of DM15,000-25,000/life-year saved ($9000-15,000) it can be recommended for secondary prevention. The application of statins in primary prevention has also proved to be clinically effective. But with a cost-effectiveness ratio of DM330,000/life-year saved ($195,000) they cannot be generally advocated in patients with hypercholesterolaemia. However, the treatment has to be considered for high risk patients. Aspirin prevention seems to be an alternative in patients without additional risk factors.

Cardiovascular Diseases↗
PubMed1997

[Color-coded duplex ultrasonography of the orbit in central vein thrombosis].

PURPOSE: To evaluate the haemodynamic findings of orbital vessels in patients with central retinal vein occlusion by colour coded duplex sonography. METHODS: In 24 patients suffering from central retinal vein occlusion, confirmed by ophthalmoscopy and fluorescence angiography, colour-coded duplex sonography of central retinal vein, central retinal artery, posterior ciliary arteries and ophthalmic artery of the affected, and the unaffected contralateral eye, was performed and compared to a control group (150 healthy subjects). RESULTS: In eyes with central retinal vein occlusion, the maximum velocity of the central retinal vein was on average 4.55 cm/s (+/-2.37 cm/s) and, as compared with the unaffected eye (mean: 6.56 +/- 1.47 cm/s) and the control group (5.97 +/- 2.37 cm/s), reduced significantly. In the affected eyes, the end diastolic velocity of the central retinal artery was reduced and the pulsatility index was increased significantly, compared with the unaffected eyes and the control group. Compared with the control group, the peak systolic and end diastolic velocities of the ophthalmic artery were significantly reduced. CONCLUSION: In conclusion, the findings assessed by colour-coded duplex sonography show a flow reduction in the central retinal vein and an increased arterial flow resistance in the retinal layer. There is good correlation with the angiographic results. Moreover, flow reductions in the ophthalmic artery, which are not seen in ophthalmological examinations, can be detected by this new examination technique.

Adult↗
PubMed1997

Clinical significance of three-dimensional helical CT in neurosurgery.

The authors report about a 3-years experience with helical CT and 3-D surface reconstruction applied in neurosurgical patients. All examinations were performed in addition to preexisting diagnostic CT, MRI, or angiography. The aim of this study was to assess the clinical value of this method with regard to planning of the surgical approach to anterior, middle, and posterior skull base and spinal lesions. 75 examinations of 55 patients were analysed and ranked as follows: A = examination with significant additional information for neurosurgical planning of skull base or spinal procedures or for postoperative evaluation of the neurosurgical approach, B = examination with some useful information for the neurosurgical planning or postoperative control, however, without significant advantage as compared to established diagnostic methods, C = examination without significant additional information. Classification was performed independently by two experienced surgeons. Examinations of anterior, middle, and posterior skull base lesions including cerebral aneurysms were in the majority rated as helpful and significantly informative, (A = 21, B = 24, C = 9, n = 54). Three-dimensional imaging of the spine was of clinical value only in specific cases (A = 6, B = 6, C = 9, n = 21). The authors conclude that three-dimensional imaging is a valuable diagnostic tool for pre- and postoperative imaging of tumorous and vascular lesions adjacent to the skull base, allowing for optimal surgical approaches with minimal invasiveness.

Adult↗
PubMed1997

Color-coded duplex sonography of experimentally induced multilevel stenosis. Evaluation of poststenotic Doppler spectrum.

RATIONALE AND OBJECTIVES: The authors evaluated the influence of a proximal arterial stenosis on the poststenotic doppler spectrum of a second, distal stenosis and determined duplex parameters, which permitted description of the severity of the distal stenosis. METHODS: Moderate (ie, 50%) and severe (ie, 90%) stenoses of the distal aorta and the distal iliac arteries of 10 pigs were created surgically and characterized by angiography. All possible combinations of moderate and severe stenoses were examined. The Doppler spectrum was depicted in the distal iliac and distal femoral arteries of both limbs and analyzed by use of maximum and minimum flow velocity (Vmax, Vmin), acceleration index (modified Handa index), acceleration time, and pulsatility index. RESULTS: In cases of moderate as well as severe proximal stenosis, acceleration index, acceleration time, and pulsatility index of the poststenotic curve of the distal stenosis were significantly reduced (P < 0.05). Independent of the severity of the proximal stenosis, differentiation of moderate as well as severe distal stenosis was possible (P < 0.05) with these parameters. CONCLUSIONS: Despite interference of spectral curves in proximal and distal stenosis, duplex sonography enabled the differentiation of experimental aortic iliac multilevel stenosis.

Animals↗
PubMed1996

Computed tomography of experimental liver abscesses using a new liposomal contrast agent.

RATIONALE AND OBJECTIVES: Evaluation of computed tomographic enhancement characteristics of a new liposomal contrast agent (liposomal iodixanol [LI]) in a pyogenic liver abscess model in 17 rabbits. METHODS: Eight to 14 days after abscess induction (Escherichia coli), density-time curves were calculated for regions of interest in liver, abscess wall and center, spleen, portal vein, abdominal aorta, inferior vena cava, and kidney. Images were obtained every minute between 1 and 10 minutes, every 5 minutes between 15 and 60 minutes, and 75 minutes after 200 mg/kg LI application (group A: 7 rabbits) and after 600 mg/kg iopentol application (group B: 10 rabbits), and 90, 105, and 120 minutes after LI. RESULTS: The abscess wall-liver contrast after LI lasted from 10 to more than 120 minutes with a maximum of 30 delta Hounsfield Units (HU) at 45 minutes. For iopentol, the abscess wall-liver contrast lasted from 2 to 7 minutes with a maximum of 8 delta HU at 5 minutes. The abscess wall-center contrast after LI lasted from 1 to more than 120 minutes with a maximum of 112 delta HU at 40 minutes. For iopentol, the abscess wall-center contrast lasted from 1 to 75 minutes with a maximum of 79 delta HU at 1 minute. The liver-portal vein contrast after LI lasted from 1 to more than 120 minutes with a maximum of 100 delta HU at 20 minutes. For iopentol, the liver-portal vein contrast lasted from 1 to 8 minutes with a maximum of 38 delta HU at 2 minutes. An abscess wall was detected in a higher percentage of the LI images (86% LI, 56% iopentol), and images in the LI group correlated better with histopathology. CONCLUSIONS: The diagnostic value of LI exceeds that of iopentol in terms of overall abscess contrast and duration of the diagnostic interval. The higher hepatic vessel contrast allows better abscess localization.

Animals↗
PubMed1995

[Color-coded duplex ultrasonography in the diagnosis of renal artery stenosis].

PURPOSE: Colour-coded duplex sonography was performed for diagnosis of renal artery stenosis to define standards and criteria for stenosis. MATERIAL AND METHODS: In 20 normotensive volunteers and 123 patients with arterial hypertension, bilateral intrarenal Doppler spectra were examined and the following parameters including side ratios were calculated: pulsatility index (PI), resistance index (RI), acceleration time index (AT) and acceleration index (AI). RESULTS: In 29 of the 123 patients, angiography showed unilateral renal artery stenosis. Acceleration index (AI) was found as the most reliable parameter with a sensitivity of 100% and a specificity of about 94% for stenoses grading at least 70%. CONCLUSIONS: Colour-coded duplex sonography can depict relevant stenoses reliably, but anatomical variations may limit its value as a single screening method. Colour-coded duplex sonography can be, therefore, recommended as an adjunct to angiography for assessment of haemodynamic relevance.

Adolescent↗
PubMed1995

Repeated administration of recombinant human insulin-like growth factor-I in patients after gastric surgery. Effect on metabolic and hormonal patterns.

OBJECTIVE: The primary objective of this investigation was to evaluate the anticatabolic effects of repeated subcutaneous administration of recombinant human insulin-like growth factor-I (rhlGF-I) in patients after gastric surgery. SUMMARY BACKGROUND DATA: The anabolic and protein-sparing effects of growth hormone are primarily mediated by IGF-I. Malnutrition and catabolic states result in increasing blood levels of growth hormone and decreasing levels of IGF-I. Experimental data showed that exogenous IGF-I could attenuate or reverse catabolism. METHODS: After giving their written informed consent, 38 male and female patients undergoing gastrectomy (age 40-75 years, body mass index 17-30 kg/m2) were treated with 80 micrograms/kg body weight rhlGF-I or placebo in a prospective, randomized, double-blind study for 5 consecutive days. Patients received a standardized total parenteral nutritional regimen with 3 g/kg body weight glucose and 0.1 g/kg body weight nitrogen. Nitrogen balance and 3-methylhistidine excretion were measured daily. Hormone profiles (IGF-I, IGFBP1, IGFBP3, cortisol, insulin, glucagon, triiodothyronine [T3], levothyroxine [T4], and thyroxine-binding globulin) were taken.

Adult↗
PubMed1995

Clinical relevance of sonometry-derived tumour thickness in malignant melanoma--a statistical analysis.

High-frequency sonography has been shown to be a useful tool in planning operative strategy in the surgery of malignant melanoma (MM). The purpose of the present study was to compare sonometric and histometric data of tumour thickness in primary cutaneous MM, applying statistical methods in order to evaluate the pre-operative relevance of sonometry. The thickness of 259 melanomas was measured preoperatively by a 20-MHz B scan, and postoperatively by histometry. Statistical analysis was performed using Pearson's correlation coefficient and absolute and relative differences. Although the correlation between sonometry and histometry was good (r = 0.88), there was a mean difference of 0.39 mm (relative difference 28%). Overall, sonometry was in agreement with the corresponding histological classes in 75% of cases. However, tumours assessed by ultrasound as between 0.55 and 0.95 mm thick were incorrectly classified according to histology in 34%, and those between 1.30 and 1.70 mm were incorrectly classified in 50% of cases. Our data reveal greater differences between sonometry and histometry using appropriate statistical methods. A concept to assess differences between sonometry and histometry is recommended.

Adolescent↗
PubMed1995

Occupational contact dermatitis in bakers, confectioners and cooks. A population-based study.

A population-based study was performed to investigate incidence rates of occupational skin disease (OSD) in bakers, confectioners and cooks, as well as the rôle of endogenous and exogenous risk factors. In North Bavaria, all closed cases of OSD were recorded systematically in a 3-year period and the total number of employees in the food industry was known over the same period of time. Incidence rates of OSD and relative risks of atopic skin diathesis (AD) and respiratory atopy (RA) were calculated. The overall incidence rate (I) of OSD (in 3 years per 10.000 employees) was 67 (95% CI 58;76) in these occupations. Bakers had a higher risk of OSD, with an incidence of 191 (95% CI 156;226) compared to confectioners with I = 84 (95% CI 55;113) and cooks I = 34 (95% CI 28;40). Incidence rates were sex- and age-related. Females developed OSD with an incidence rate of 74 (95% CI 64;84) compared to males with I = 58 (95% CI 48;70). OSD occurred mostly between the ages of 15 and 24 years. Irritant contact dermatitis (ICD) was the main type of OSD. 36% of the bakers had an occupationally relevant Type I allergy, while Type I allergies were less frequent in confectioners (16%) and cooks (9%). Assuming a prevalence of 10% of AD in the general population the relative risk (RR) of developing OSD in bakers, confectioners and cooks with AD was 9.7, 10.5 and 5.2, respectively. There were only small differences in calculating sex-related RR of AD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Diagnosis of an infected thrombus of the inferior vena cava with ultrasound and computerized tomography].

The incidence of central venous catheter-associated thrombosis is up to 66%; nevertheless, in most cases it is of little clinical importance. A rare, but serious complication is infection of a catheter-associated thrombosis, which occurs in 7-16%. We report the case of a 16-year-old male patient, who suffered from meningitis and Waterhouse-Friderichsen syndrome. After initial improvement in the intensive care unit, he developed septic temperatures, caused by an infected thrombus of a central venous catheter in the inferior vena cava. Color-coded ultrasound showed hyperechogenic signals and missing flow detection at the catheter tip. Computed tomography showed air bubbles in the thrombosed catheter tip and confirmed the diagnosis. Vascular surgery was done and an infected, 17-cm-long infected thrombus was removed. The recent literature on this topic is reviewed.

Adolescent↗
PubMed1995

Influx of antibiotics into diabetic legs with plantar ulcerations: regional and systemic Netilmycin levels compared after retrograde-venous and systemic-venous application.

Retrograde venous perfusions (RVP) of antibiotics were proven to be therapeutically more effective than systemic venous infusions (SVI) in patients with infected diabetic neuropathic plantar ulcers (DNPU: no additional macronagiopathy of leg arteries). In order to study some pharmakokinetic features of RVP application paratibial tissue levels of Netilmycin (NL; from suction blister fluid) and cubital venous NL were compared under each SVI and RVP therapy in 8 patients with DNPU. Tissue (11.6 +/- 6.4 micrograms/l) were significantly higher (p < 0.001) an within the therapeutic range after RVP (SVI: 4.31 +/- 1.68). In ulcer transsudate (RVP only; n = 4) NL mounted to 36.4 +/- 11.6 microgram/ml. Peak and base NL in cubital blood were within the normal range for both SVI and RVP (no significant difference). The date indicate that RVP is superior to SVI application of Netilmycin (and probably other antibiotics) as surmounting the damaged microcirculation in DNPU to achieve effective drug levels in the target tissue.

Aged↗
PubMed1994

[Therapeutic superiority of regional retrograde venous antibiotic pressure infusion versus systemic venous infusions in diabetic patients with infected neuropathic plantar ulcers].

Since systemic treatment of neuropathic plantar ulcers in diabetics (DNPU) has so far been rather ineffective, recent reports of successful management of DNPU by short-term retrograde transvenous leg perfusion (RVP) by South American angiologists encouraged us to apply this treatment method in diabetics suffering from chronic DNPU. Hence, in a prospective comparative clinical trial started in 1989 we have treated 45 male diabetics suffering from DNPU with the same daily doses of netilmycin, administered either in systemic venous infusions (SVI: n = 21, three times/day) or in RVP (n = 24, once/day). After 10 consecutive days of treatment, ulcers had closed in 8 of the 24 patients treated with RVP, as against 3 of the 21 treated with SVI. Diminution of the ulcer area by > 30% including full debridement was achieved in 10/24 of the RVP cases (SVI: 4/21). During 6 months of follow-up, amputation of toes or forefoot was necessary in only 1 patient in the RVP group, but in 4 in the SVI group. Partial restitution of osteolytic damage was observed in some cases after RVP. Our results show that regional netilmycin therapy given by the RVP procedure is clearly superior to equal netilmycin doses administered by SVI for the treatment of DNPU. RVP can be recommended in DNPU, particularly when the ulcers are complicated by infections.

Adult↗
PubMed1994

[Idiopathic pustular and bullous variants of Sweet syndrome].

We report on the case of a 62-year-old patient with disseminated pustular plaques affecting especially his face and hands. These lesions exhibited severe blistering later in the course. The diagnosis of an unusual variant of an acute febrile neutrophilic dermatosis (Sweet's syndrome) was histologically confirmed. Pustular lesions are known to occur in Sweet's syndrome. Secondary development into bullous lesions, however, has not previously been described. No associated disease has so far been detected.

Biopsy↗
PubMed1994

["Granulomatous slack skin"--cutaneous elastolytic lymphoma].

The term "granulomatous slack skin" (GSS) was introduced by Ackerman for a disease first described by Convit et al. in 1973. GSS represents a rare cutaneous lymphoma characterized by localized elastolytic lesions with a granulomatous infiltrate. We recently observed two male patients with the characteristic features of this disease. Both patients responded well to therapy with interferon-alpha 2b. In one patient clinical remission was stable under long-term treatment with clofazimine. We report on common features of these two patients and give a review of the cases published in the literature.

Biopsy↗
PubMed1994

[The palliative treatment of venous stenoses in tumor patients with self-expanding vascular prostheses].

During 53 months 14 patients with tumour-induced obstructions of the superior vena cava (n = 8), the inferior vena cava (n = 2) and iliac veins (n = 4) were treated with self-expandable metallic stents. 21 Wall stents and 5 Gianturco double stents were applied. The follow-up lasted from 2 weeks to 16 months (range = 5.7 months). All patients showed a marked relief of inflow obstruction after stent placement. 6 of 7 patients, who died of their disease during follow-up, were asymptomatic regarding vein obstruction until their death (3 weeks to 16 months). In 6 of 7 still living patients no re-obstruction occurred during follow-up (2 to 16 months). Patency rate was 82%. These results suggest that self-expanding stents are a successful palliative therapy of malignant vein obstructions.

Constriction, Pathologic↗