Occupational exposure to hazardous substances and risk of cancer in the area of the mouth cavity, oropharynx, hypopharynx and larynx. A case-control study

A case-control study of squamous cell carcinoma of the upper aerodigestive tract conducted in Heidelberg and Giessen (FRG) provided information on occupational factors in 200 patients and 800 controls (adjusted to sex, age and area of living; 4:1 matched design). The number of subjects exposed to wood dusts, organic chemicals, coal products or to cement was significantly elevated in the tumour group. An increased risk for head and neck cancer was observed after exposition to wood dust (RR = 2,2), organic compounds (RR = 2,4), coal products (RR = 2,7) and especially to cement (RR = 4,4). The cancer risk due to cement exposition showed a positive correlation to the duration of exposition and remained significantly elevated after adjustment for alcohol and tobacco consumption.     

Deformation behaviour of bovine cancellous bone.

Repetitive cyclic loading from daily activities is reported to induce fatigue damage and microcracking in bone structures. In terms of osteoporotic structures or in cases of serious damage of skeleton segments and the replacement by metallic implants the degree of damage due to cyclic loading will be even more pronounced. It is generally assumed that fatigue induced cracking and crack propagation essentially act as driving forces for complex physiological phenomena such as remodelling processes of bones and the adaptation to applied loads. In cases where the crack propagation rate exceeds the remodelling velocity, sudden and unexpected fracture of the bone is observed. Especially for implant reinforced structures the deviation in stiffness to the bone material can induce high peak stresses and accelerate crack propagation. Whereas, for cortical bone the mechanical behaviour under cyclic loading is sufficiently described, only rough data are available for trabaecular structures. In this study the deformation behaviour of bovine vertebra trabecular bone specimens is investigated under cyclic compressive loading. A powerlaw relationship was found between the applied load ratio and cycles to failure. A linear decrease of maximum, integral strains at failure with increasing applied load ratio was observed. Optical deformation measurement of the surface strains revealed that low strains (0-1 increasing applied load ratio whereby the higher strains behave directly opposite. This indicates that different failure mechanisms are acting at low cycle and high cycle fatigue, respectively.     

Estimation of average flow in ungated 3D phase contrast angiograms

Three dimensional (3D) phase contrast angiograms contain velocity data, which is discarded after the reconstruction of the projections. In extension to earlier work on velocity quantification with ungated 2D phase data, this paper shows that a useful estimate of the average velocity and flow rate can be extracted from ungated 3D phase contrast angiograms. Simulations and experiments in a phantom and in vivo were performed. For pulsatile flow and strong spin saturation, an over-estimation of the flow rate at the net in-flow end of the imaging volume and underestimation at the net out-flow end was observed. Imaging at lower RF tip angles yielded flow rates close to the correct value within the entire imaging volume. In contrast to ungated 2D experiments, the flow rates determined by repeated 3D experiments showed no variation.     

Tamoxifen and kallikrein in therapy of oligoasthenozoospermia: results of a randomized study

Because of the good results achieved with tamoxifen in the treatment of oligozoospermia and with kallikrein in the treatment of asthenozoospermia, a randomized study of the combined treatment of oligoasthenozoospermia suggested itself. 67 patients with idiopathic normogonadotropic oligoasthenozoospermia were treated with 30 mg tamoxifen/day (n = 33) or with 30 mg tamoxifen/day and additionally 600 IU kallikrein/day (n = 34). It was shown that, apart from a significant increase in sperm density in both groups, the combination therapy also resulted in an overall significant increase (p less than 0.02) in sperm motility. Sperm morphology and the swell test remained unaffected. After 3 months of therapy, 4 pregnancies occurred in each group. In ejaculates with a sperm density of less than 10 million/ml not even one sperm parameter was significantly affected in any of the groups, while with an initial value of more than 10 million/ml the increase in motility was more significant (p less than 0.008) in the group with additional kallikrein therapy (n = 18). In the monotherapy group, no significant therapeutic effect on sperm motility was seen even in patients with a sperm density of more than 10 million. The combination of tamoxifen and kallikrein therefore seems to constitute an improvement of the systemic therapy of male subfertility in patients with moderately severe oligoasthenozoospermia.     

Tendon injuries of the knee joint extensor mechanism

Diagnosis, aetiology and therapy of injuries to the extensor mechanism of the knee joint are presented. 22 cases of ruptures and discisions of the lig. patellae or the quadriceps tendon could be reexamined. All cases but one, with operation within the first week after injury, suturing with absorbable or non absorbable material, immobilisation for 6 weeks and following physical therapy, had a good functional result. No rerupture occurred. In one case a limitation of the range of movement had to be seen afer an open discision of the lig. patellae. After transposition of the tuberositas tibiae, discission of the scares and functional therapy a good result could also be achieved.     

Rotational tomography of the normal and reconstructed middle ear in temporal bones: an experimental study

Imaging is an essential diagnostic tool in reconstructive middle ear surgery, especially in pre-operative planning. Due to ongoing improvement of imaging quality and development of new imaging techniques like e.g. rotational tomography (RT) post-operative follow-up and immediate evaluation of surgical results may become more important. The aim of this experimental study was to evaluate RT as a new tool for postoperative determination of middle ear anatomy and implant position in temporal bones. RT was performed in ten temporal bone specimen after insertion of different middle ear prostheses concerning material, shape and length (PORP; TORP; Stapes piston). An implantable hearing device (Symphonix Soundbridge®) was also implanted and visualized. For comparison some specimen additionally underwent conventional computed tomography (CT), including the newest technology. Characterization of anatomical structures of the temporal bone using RT was of comparable quality to conventional CT-scans in all investigated specimen while requiring approximately 30% of the CT’s irradiation exposure. Unlike CT the RT showed almost no problems due to metallic artefacts of the implanted prostheses. Furthermore RT enabled a 3-dimensional view of the temporal bone and angle determination of inserted prostheses towards the tympanic membrane and/or the malleus handle. Detailed imaging of the prostheses allowed determination of shape, material and localization within the specimen’s reconstructed middle ear. The new imaging technique of RT allows precise presentation of anatomical structures and middle ear implants in temporal bones. Following these experimental results it will be our future work to evaluate this method in clinical practise.     

Effects of acute nicotine administration on the function of the human parotid gland

The effect of acute administration of nicotine on the secretory function of the human parotid gland was investigated in 4 male volunteers. After intravenous infusion of 20 micrograms nicotine/kg b.w. within 10 min in all subjects an increased salivary amylase activity and protein concentration was observed. This phenomenon is believed to be caused by a stimulation of parotid beta-adrenoceptors secondary to a nicotine-induced release of catecholamines from the adrenals.     

Thrombosis of the internal jugular vein in therapy with hematopoietic growth factors. A case report

Thrombosis of the internal jugular and subclavian vein is often caused by central venous catheters. We report on a 39-year-old patient suffering from clinically suspected thrombosis of the internal jugular and subclavian veins. Thrombosis was confirmed by B-mode-sonography. The development of thrombosis in this case as a consequence of a central venous catheter and of an additional continuous i.v. treatment with human granulocyte/macrophage colony-stimulating factor (GM-CSF) is discussed.