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Biomedical subjects

T Zimmermann

Publications and source records attributed to T Zimmermann.

At least 19 recordsLinked to original sources

Ultrastructural appearance of embedded and polished wood cell walls as revealed by Atomic Force Microscopy.

Atomic Force Microscopy (AFM) was used to investigate the ultrastructural appearance of transverse wood cell wall surfaces in embedded and polished Norway spruce wood blocks. The prepared surfaces showed only little height differences, suitable for high resolution AFM phase contrast imaging. Our results revealed randomly arranged wood cell wall components in the thick secondary 2 (S2) layers of the tracheid cell walls. It is concluded that the observed distribution pattern of the cellulose fibril/matrix structure is close to the original cell wall structure. In this context, the plasticity of wood cell wall components to re-arrange and adjust to different conditions resulting in diverse structural pattern is discussed.

Cell Wall↗

Infragenicular polytetrafluoroethylene bypass with tapered versus straight vascular grafts: results from a prospective multicenter cohort study.

Both straight and tapered arterial grafts are commonly used for infragenicular bypass surgery. Opinions vary considerably regarding the use of each type of graft and depend on individual experience, as no trial yet has assessed clinical outcomes comparing both groups. We conducted a prospective, multicenter, cohort study to analyze results for each graft type. From a total of 81 patients, 50 underwent infragenicular bypass surgery with straight PTFE prostheses and 31 with tapered prostheses in a prospective, multicenter trial. Six different centers for vascular surgery took part in the trial. In clinical follow-up at discharge as well as 3, 6, 12, 18, 24, and 36 months after revascularization, various parameters were evaluated comparing patency rates, limb salvage, and major amputation rates. Significant differences were found in limb salvage rates between the two groups. Patients receiving a straight graft fared better in this regard. Further data suggest that short-term primary patency is also improved in straight prostheses. Sixty-four percent of these remained patent after 1 year, while only 50% of tapered prostheses were still patent. No differences between the groups were found for secondary patency. The advantages of straight prostheses seem to be reduction of thrombus formation and intimal hyperplasia. Furthermore, it appears that the surgeons participating in this study prefer the use of straight prostheses. Even though the group of patients that received tapered grafts had slightly more unfavorable preoperative conditions, the data still support the superiority of straight vascular grafts. However, prospective randomized trials are necessary to evaluate the benefit of different bypass designs definitively.

Aged↗

Attitude of German women and gynecologists towards long-cycle treatment with oral contraceptives.

Long-cycle regimens with continuous use of oral contraceptives (OCs) for 3 or 6 months followed by a hormone-free interval of 7 days may reduce or prevent cycle-dependent and menses-related complaints. A representative survey carried out with 1195 German women in different age groups revealed that only 26-35% of the women aged between 15 and 49 years preferred monthly bleeding, while 37-46% wished to never bleed. The reasons for the refusal of regular menstruations were fewer severe menstrual complaints, better hygiene, higher quality of life, and less blood loss. Among the women who preferred regular withdrawal bleeding during the use of OCs, the main reasons were fear of pregnancy, infertility and adverse effects, and that menstruations were natural. Between 32% and 54% of the women would suppress menstruation sporadically and 11-14% for a longer period of time. After continuous treatment with a combination of 30 microg ethinyl estradiol and 2 mg dienogest for 6 months, the majority of women preferred the long-cycle regimen as compared to the conventional OC regimen despite a higher rate of irregular bleeding. Bleeding occurred primarily in first-time users of OC, particularly during the administration of the second OC pack. A survey carried out with German gynecologists revealed that most physicians prescribed extended OC cycles primarily for medical reasons, e.g., dysmenorrhea, hypermenorrhea, endometriosis and premenstrual dysphoric disorder. The gynecologists preferred a regimen with three packs of extended use of OCs.

Adolescent↗

[Effectiveness of an outpatient disease management programme for chronic heart insufficiency patients].

The effectivity of a disease management programme (DMP) for outpatients suffering from chronic heart insufficiency (CHI) in primary care is presented. The programme is predominantly based on a weekly telephone monitoring by a case manager using a standardised questionnaire that scores CHI-relevant information of the patient. If the score exceeds a predefined limit the patient's general practitioner is alarmed. An observational study including a total of 115 patients indicates a significant decline of the hospital admission rate (p < 0.0001), as the primary outcome measure, whereas the total length of hospitalization remained constant. The findings are compared with other studies' results and the aims of a randomised controlled trial on the efficacy of DMP on patients with chronic heart failure are discussed.

Aged↗

[Doubtful evidence for the use of the cholinesterase inhibitor donepezil in patients with dementia--a systematic review].

OBJECTIVE: Objective of this systematic review is to determine the level of scientific evidence for the use of Donepezil in Alzheimer's Disease. METHODS: Ten randomised controlled double-blind trials testing Donepezil versus Placebo were identified in MEDLINE and EMBASE. All ten trials were included in this systematic review. Following a detailed catalogue of criteria the methodological standard of the ten trials was assessed. RESULTS: The authors of eight trials postulated statistically significant differences in favour of Donepezil. Unfortunately, the methodological standard of all studies was insufficient. The methodological shortcomings are discussed in detail. CONCLUSION: With regard to severe methodological deficiencies the evidence for the use of Donepezil in moderate to severe Alzheimer's Disease is lacking. But even if the trials had been conducted in a methodologically correct way the clinical relevance of the postulated positive results would have to be questioned.

Aged↗

Impact of tranexamic acid vs. aprotinin on blood loss and transfusion requirements after cardiopulmonary bypass: a prospective, randomised, double-blind trial.

INTRODUCTION: Aprotinin (AP) reduces blood loss and transfusions after cardiopulmonary bypass (CPB), but may sensitise patients and is expensive. Tranexamic acid (TA) has less side-effects, but data regarding its efficacy are controversial. The aim of our prospective, randomised, double-blind study was to compare the impact of AP vs. TA on drainage blood loss and transfusion requirements in patients undergoing first time CABG on CPB. MATERIALS AND METHODS: One hundred and twenty adult patients were randomised to receive either high-dose AP according to Hammersmith or a total of 2 g TA. Perioperative blood products were transfused in a standardised fashion. Blood loss was measured up to 24 h. Demographic and clinical patient data were collected until hospital discharge. RESULTS: The data from 118 patients (TA: n = 58, AP: n = 60) who completed the study according to protocol were analysed. Blood loss at 24 h postoperation in TA patients was significantly higher (896 +/- 354 ml) as compared to AP patients (756 +/- 347 ml; p = 0.03). TA patients received 1.5 +/- 1.5 units of red blood cells (AP: 1.5 +/- 1.7, p = 1.0), 1.3 +/- 2.0 units of fresh frozen plasma (AP: 1.0 +/- 2.0, p = 0.38) and 0.5 +/- 1.4 units of platelets (AP: 0.2 +/- 0.7, p = 0.15). Clinical data, including perioperative myocardial infarction rate, acute renal failure, mechanical ventilation, hospital stay and mortality, were not significantly different between either group. CONCLUSION: Our data show a difference in blood loss between TA and high-dose AP. Although statistically significant, it has little clinical relevance, because perioperative transfusion requirements were similar for both groups. Thus, TA appears to be a cost-effective alternative to AP in primary CABG patients.

Antifibrinolytic Agents↗

[Facial folliculo-sebaceous cystic hamartoma. Treatment with CO2 and Er:YAG lasers].

Folliculo-sebaceous cystic hamartoma (FCH) is defined as an adnexal hamartoma. The histopathological findings of FCH are equivalent to a very late stage of trichofolliculoma. The clinical appearance of FCH is unspecific. For this reason in the majority of cases it is only the histopathological examination that leads to the diagnosis of FCH. Up to now FCH has been treated with surgical procedures. We combined the use of both CO2 and Er:YAG lasers to treat a facial FCH.

Combined Modality Therapy↗

Alterations of left ventricular function in women with insulin-dependent diabetes mellitus during pregnancy.

AIMS/HYPOTHESIS: During pregnancy, eminent cardiovascular changes occur. The aim of the following study was to investigate the course of haemodynamic parameters under the increased volume load during pregnancy and delivery in women with insulin-dependent diabetes mellitus. METHODS: We examined 51 pregnant diabetic women and 51 healthy pregnant women. The control group consisted of 51 healthy non-pregnant women. In all women, left ventricular mass and fractional shortening were calculated. To evaluate left ventricular diastolic function, mitral inflow and pulmonary venous flow profiles were analysed. RESULTS: During pregnancy left ventricular mass increased, fractional shortening decreased and diastolic dysfunction was found. While the healthy pregnant women developed signs of disturbed relaxation during pregnancy, pregnant diabetic women showed signs of a disturbed relaxation at the beginning of gestation. Of the pregnant diabetic women, 29 developed a restrictive filling pattern at the 24th week of gestation. The remaining 22 diabetic women had a comparable restrictive filling pattern only during vaginal delivery. In 10 of the 29 pregnant diabetic women dangerous complications were documented, while there were no complications in the healthy pregnant women and the other 22 diabetic pregnant women. CONCLUSION/INTERPRETATION: In healthy women pregnancy results in a reversible physiologic left ventricular hypertrophy, a disturbed relaxation pattern and a temporary decrease of left ventricular systolic function. In contrast, pregnant diabetic women showed a delayed relaxation at the beginning of pregnancy and developed a restrictive filling pattern. The early development of a restrictive filling pattern could indicate complications during delivery in pregnant diabetic women.

Adult↗

Fetal tissue Doppler echocardiography: detection rates of cardiac structures and quantitative assessment of the fetal heart.

OBJECTIVES: Tissue Doppler echocardiography (TDE) has been developed in adult cardiology, but only recently has it been applied to fetal heart studies. We implemented TDE on a high-resolution ultrasound system used for prenatal scanning by changing the Doppler settings, but without specific TDE equipment, to study cardiac tissue motion of normal fetuses in the second and third trimesters. METHODS: Using color Doppler settings optimized for low velocity motion assessment, detection rates of cardiac structures were measured in 47 fetuses. With pulsed Doppler, axial diastolic and systolic cardiac wall velocities were recorded in another 30 fetuses. RESULTS: In all fetuses TDE could detect cardiac wall motion. The right ventricular wall and the level of the atrioventricular valves were most easily seen. Axial contraction velocities of the fetal heart increased with gestational age. CONCLUSIONS: TDE can be used to study normal fetal cardiac function throughout gestation. A regular ultrasound system without additional hardware or software is suitable for screening studies using TDE.

Cross-Sectional Studies↗

[Penetrating knife injury of the heart. Emergency management and definitive treatment: case report and review of the literature].

The outcome of patients with penetrating heart injuries depends to a great extent on aggressive primary care and fast transport to the closest appropriate trauma center. There, after confirming the diagnosis, the injured victim has to be transferred without any delay to the operating room where the penetrating injury can be dealt with. The importance of resolute emergency management is shown based on a case presentation and a review of the current literature. The employment of extracorporal circulation (heart-lung machine) is rather subordinate in the primary care of these patients.

Adult↗

[Alterations of left ventricular systolic and diastolic function in pregnant women with insulin-dependent diabetes mellitus].

BACKGROUND: During pregnancy, major cardiovascular changes occur. The aim of the following study was to investigate the course of hemodynamic parameters under the increased volume load during pregnancy and delivery in women with insulin-dependent diabetes mellitus. METHODS: We examined 51 pregnant diabetic and 51 healthy pregnant women. The control group consisted of 51 healthy non-pregnant women. In all women, left ventricular mass and fractional shortening were calculated. To evaluate left ventricular diastolic function, mitral inflow and pulmonary venous flow profiles were analyzed. RESULTS: During pregnancy left ventricular mass increased, fractional shortening decreased and diastolic dysfunction was found. While the healthy pregnant women developed signs of disturbed relaxation during pregnancy, pregnant diabetic women showed signs of a disturbed relaxation already at the beginning of gestation. A total of 29 pregnant diabetic women developed a restrictive filling pattern already at the 24th week of gestation. The remaining 22 diabetics had a comparable restrictive filling pattern only during vaginal delivery. In 10 of the 29 pregnant diabetic women dangerous complications were documented, while there were no complications in the healthy pregnant women and the other 22 diabetic pregnant women. CONCLUSIONS: In healthy women pregnancy results in a reversible physiologic left ventricular hypertrophy, a disturbed relaxation pattern and a temporary decrease of left ventricular systolic function. In contrast, pregnant diabetic women demonstrated a delayed relaxation at the beginning of pregnancy and developed a restrictive filling pattern. The early development of a restrictive filling pattern may predispose to complications during delivery in pregnant diabetic women.

Adolescent↗

Recurrent isolated calf muscle thrombosis due to a venous aneurysm of the soleal muscle veins.

A rare case of venous aneurysm involving the soleal muscle vein in an 18-year-old woman is presented. The patients showed three episodes of ultrasonographically proven calf muscle thrombosis within 2 years. After a short course of low-molecular-weight heparin at a therapeutic dosage, complete thrombus recanalization was achieved. To prevent further thrombotic episodes, surgery including ligation and resection of the aneurysm was performed. At the 3-month follow-up study the patient had completely recovered.

Adolescent↗

Impact of n-3 fatty acid supplemented parenteral nutrition on haemostasis patterns after major abdominal surgery.

In various diseases n-3 fatty acids exert anti-inflammatory properties. These effects seem to be related to the uptake and incorporation of eicosapentaenoic acid (EPA) into the cellular substrate pool after dietary intake of EPA, which is contained in fish oils (FO). In the state of inflammation EPA is released to compete with arachidonic acid (AA) for metabolism at the cyclo-oxygenase and the 5-lipoxygenase level. The metabolites of EPA have less inflammatory and chemotactic potency than the substances derived from AA. In addition to positive effects, early studies pointed towards prolonged bleeding times after dietary intake of n-3 fatty acids. This study was undertaken to address the issue of potential coagulation disturbances associated with postoperative parenteral FO administration. This was a prospective, randomised, double blinded clinical trial, carried out in two operative intensive care units (13 and 16 beds) in a university hospital. Forty-four patients undergoing elective major abdominal surgery participated in the trial. Patients were randomly assigned to receive total parenteral nutrition (TPN) supplemented with either soybean oil (SO, Lipovenoess 10% PLR; 1.0 g/kgBW per day; n = 20) for five days or with a combination of FO and SO (FO, Omegaven; 0.2 g/kgBW per day plus SO, Lipovenoes 10% PLR; 0.8 g/kgBW per day, n = 24), respectively. Blood samples were taken preoperatively (day -1), prior to (day 1) during (days 2-5) and after TPN (day 6). The coagulation parameters thromboplastin time (Quick), activated partial thromboplastin time (aPTT), fibrinogen and antithrombin III were measured. To differentially assess activation levels of extrinsic and intrinsic coagulation pathway, factors VIIa and XIIa were quantified. Moreover platelet function was determined by resonance thrombography. Baseline values of coagulation and platelet function were comparable in both groups, but coagulation activity dropped after surgery. Over the observation period of 6 days, however, physiological levels were regained. No clinically significant differences were observed between the SO- and SO + FO- group. These findings suggest that infusion of fish oil in doses up to 0.2 g/kgBW per day is safe regarding coagulation and platelet function.

Aged↗

Clinical findings with the oral contraceptive combination ethinylestradiol/dienogest in the Czech Republic.

The efficacy and safety of the low dose monophasic oral contraceptive (OC) combination containing 30 micrograms of ethinylestradiol (EE) and 2.0 mg of dienogest (DNG) (EE/DNG) was evaluated in a prospective, open-label, multicenter, uncontrolled, phase III trial. The trial was carried out in six hospitals by 36 investigators in the Czech Republic, and included 557 healthy women (aged 18-35 years), over 12 cycles, with a total of 6051 cycles. EE/DNG provided a reliable ovulation inhibition. The contraceptive efficacy study showed an adjusted Pearl index of 0.198 on the basis of three pregnancies occurring during 6051 cycles. EE/DNG provided good cycle control, reduced the incidence of intermenstrual bleedings, the intensity of menstrual bleeding and frequency of dysmenorrhea. Due to the antiandrogenic properties of the progestogen component DNG, EE/DNG improved androgen-related conditions, such as skin blemishes, hair greasiness and acne vulgaris. From 108 women with acne, 62 (57%) improved after the 6th cycle, and 16 (15%) were healed. Similar changes were found after cycle 12. Breast tenderness and headache were the most frequent of the common complaints due to treatment with EE/DNG. The frequency of all complaints decreased steadily over time. Only 7.7% of subjects discontinued due to adverse reactions. No thrombophlebitic events were noticed.

Adolescent↗

Clinical findings with the oral contraceptive combination ethinylestradiol/dienogest in Poland.

The efficacy and safety of the low dose monophasic oral contraceptive (OC) combination containing 30 micrograms of ethinylestradiol (EE) and 2.0 mg of dienogest (DNG) (EE/DNG) was evaluated in a prospective, open-label, multicenter, uncontrolled, phase III trial. The trial was carried out in five hospitals in Poland, and included 431 healthy women (aged 18-35 years), over 12 cycles, with a total of 4608 cycles. EE/DNG provided reliable ovulation inhibition. No women became pregnant during the trial. The unadjusted Pearl index was 0. EE/DNG provided good cycle control and reduced the incidence of intermenstrual bleedings, the intensity of menstrual bleeding and frequency of dysmenorrhea. Due to the antiandrogenic properties of the progestogen component DNG, EE/DNG improved androgen-related conditions, such as skin blemishes, hair greasiness and acne vulgaris. Of 50 women with acne, 80% improved after the 6th cycle and 1 was healed. After 12 cycles, 54% were improved and 37% were healed. Breast tenderness and gastric complaints were the most frequent of the common complaints due to treatment with EE/DNG. The frequency of all complaints decreased steadily over time. Only 5.6% of subjects discontinued due to adverse reactions. No thrombophlebitic events were noticed.

Acne Vulgaris↗

Mosaic chromosomal aberrations in synovial fibroblasts of patients with rheumatoid arthritis, osteoarthritis, and other inflammatory joint diseases.

Chromosomal aberrations were comparatively assessed in nuclei extracted from synovial tissue, primary-culture (P-0) synovial cells, and early-passage synovial fibroblasts (SFB; 98% enrichment; P-1, P-4 [passage 1, passage 4]) from patients with rheumatoid arthritis (RA; n = 21), osteoarthritis (OA; n = 24), and other rheumatic diseases. Peripheral blood lymphocytes (PBL) and skin fibroblasts (FB) (P-1, P-4) from the same patients, as well as SFB from normal joints and patients with joint trauma (JT) (n = 4), were used as controls. Analyses proceeded by standard GTG-banding and interphase centromere fluorescence in situ hybridization. Structural chromosomal aberrations were observed in SFB (P-1 or P-4) from 4 of 21 RA patients (19%), with involvement of chromosome 1 [e.g. del(1)(q12)] in 3 of 4 cases. In 10 of the 21 RA cases (48%), polysomy 7 was observed in P-1 SFB. In addition, aneusomies of chromosomes 4, 6, 8, 9, 12, 18, and Y were present. The percentage of polysomies was increased in P-4. Similar chromosomal aberrations were detected in SFB of OA and spondylarthropathy patients. No aberrations were detected in i) PBL or skin FB from the same patients (except for one OA patient with a karyotype 45,X[10]/46,XX[17] in PBL and variable polysomies in long-term culture skin FB); or ii) synovial tissue and/or P-1 SFB of normal joints or of patients with joint trauma. In conclusion, qualitatively comparable chromosomal aberrations were observed in synovial tissue and early-passage SFB of patients with RA, OA, and other inflammatory joint diseases. Thus, although of possible functional relevance for the pathologic role of SFB in RA, these alterations probably reflect a common response to chronic inflammatory stress in rheumatic diseases.

Arthritis, Psoriatic↗