Induction chemotherapy (IC) followed by radiotherapy (RT) versus cetuximab plus IC and RT in advanced laryngeal/hypopharyngeal cancer resectable only by total laryngectomy-final results of the larynx organ preservation trial DeLOS-II

Background

The German multicenter randomized phase II larynx organ preservation (LOP) trial DeLOS-II was carried out to prove the hypothesis that cetuximab (E) added to induction chemotherapy (IC) and radiotherapy improves laryngectomy-free survival (LFS; survival with preserved larynx) in locally advanced laryngeal/hypopharyngeal cancer (LHSCC).

Patients and methods

Treatment-naïve patients with stage III/IV LHSCC amenable to total laryngectomy (TL) were randomized to three cycles IC with TPF [docetaxel (T) and cisplatin (P) 75 mg/m2/day 1, 5-FU (F) 750 mg/m2/day days 1-5] followed by radiotherapy (69.6 Gy) without (A) or with (B) standard dose cetuximab for 16 weeks throughout IC and radiotherapy (TPFE). Response to first IC-cycle (IC-1) with ≥30% endoscopically estimated tumor surface shrinkage (ETSS) was used to define early responders; early salvage TL was recommended to non-responders. The primary objective was 24 months LFS above 35% in arm B.

Results

Of 180 patients randomized (July 2007 to September 2012), 173 fulfilled eligibility criteria (A/B: larynx 44/42, hypopharynx 41/46). Because of 4 therapy-related deaths among the first 64 randomized patients, 5-FU was omitted from IC in the subsequent 112 patients reducing further fatal toxicities. Thus, IC was TPF in 61 patients and TP in 112 patients, respectively. The primary objective (24 months LFS above 35%) was equally met by arms A (40/85, 47.1%) as well as B (41/88, 46.6%). One hundred and twenty-three early responders completed IC+RT; their overall response rates (TPF/TP) were 94.7%/87.2% in A versus 80%/86.0% in B. The 24 months overall survival (OS) rates were 68.2% and 69.3%.

Conclusions

Despite being accompanied by an elevated frequency in adverse events, the IC with TPF/TP plus cetuximab was feasible but showed no superiority to IC with TPF/TP regarding LFS and OS at 24 months. Both early response and 24 months LFS compare very well to previous LOP trials and recommend effective treatment selection and stratification by ETSS.

Clinical trial information

NCT00508664.

Anpassung von Kleinwinkelröntgenspektren durch eine nicht-lineare Regressionsanalyse

A method for fitting of background-based curves is described whereas, with it’s aid, the peakpositions and areas in fitted spectrum sought, are easily located

DNA replication stress response involving PLK1, CDC6, POLQ, RAD51 and CLASPIN upregulation prognoses the outcome of early/mid-stage non-small cell lung cancer patients

Lung cancer is the leading cause of cancer deaths worldwide. Clinical staging classification is generally insufficient to provide a reliable prognosis, particularly for early stages. In addition, prognostic factors are therefore needed to better forecast life expectancy and optimize adjuvant therapeutic strategy. Recent evidence indicates that alterations of the DNA replication program contribute to neoplasia from its early stages and that cancer cells are frequently exposed to endogenous replication stress. We therefore hypothesized that genes involved in the replication stress response may represent an under-explored source of biomarkers. Expressions of 77 DNA replication-associated genes implicated in different aspects of chromosomal DNA replication, including licensing, firing of origins, elongation, replication fork maintenance and recovery, lesion bypass and post-replicative repair were determined in primary tumors and adjacent normal tissues from 93 patients suffering from early- or mid-stage non-small cell lung cancer (NSCLC). We then investigated a statistically significant interaction between gene expressions and survival of early-stage NSCLC patients.The expression of five genes, that is, POLQ, PLK1, RAD51, CLASPIN and CDC6 was associated with overall, disease-free and relapse-free survival. The expression levels are independent of treatment and stage classification. Except RAD51, their prognostic role on survival persists after adjustment on age, sex, treatment, stage classification and conventional proliferation markers, with a hazard ratio of 36.3 for POLQ (95%CI 2.6–517.4, P=0.008), 23.5 for PLK1 (95%CI 1.9–288.4, P=0.01), 20.7 for CLASPIN (95%CI 1.5–275.9, P=0.02) and 18.5 for CDC6 (95%CI 1.3–267.4, P=0.03). We also show that a five-gene signature including POLQ, PLK1, RAD51, CLASPIN and CDC6 separates patients into low- and high-risk groups, with a hazard ratio of 14.3 (95% CI 5.1–40.3, P<0.001). This ‘replication stress' metamarker may be a reliable predictor of survival for NSCLC, and may also help understand the molecular mechanisms underlying tumor progression.

[Subcutaneous preservation of an amputated auricle. Morphological changes]

BACKGROUND

Microsurgical replantation of an avulsed auricle remains a challenge in reconstructive surgery. Secondary reconstruction of a traumatic lost auricle is usually performed using a costal cartilage framework according to well documented techniques or with a prosthesis. In order to minimize donor-site morbidity, various efforts can be undertaken to preserve the amputated auricle by implanting the de-epithelialized cartilage framework in a subcutaneous pocket on the surface of the mastoid. Where preservation is successful, this original cartilage could be used for reconstructive treatment.

PATIENT AND RESULTS

This study describes the histologic and immunohistologic changes in a complete traumatic avulsion of the auricle with subsequent cartilage conservation for eight months within a skin pocket. Trauma, preparation and preservation were accompanied by morphologic changes that included generation of local ossification centers and infiltration of fibrous tissue. We compared the macroscopic and microscopic morphology of the amputated part to native elastic cartilage following maximal denutrition and temporary heterotopic implantation in conjunction with atypical tension and pressure properties of the retroauricular pocket.

CONCLUSION

In this case, the limited success of cartilage conservation in the subcutaneous pocket required conventional auricle reconstruction with autologous costal cartilage.

Localization of transforming growth factor-beta-expressing cells and comparison with major extracellular components in aural cholesteatoma

Transforming growth factor-beta (TGF-beta) plays an important role in the regulation of extracellular matrix (ECM) deposition by stimulating the synthesis of individual matrix proteins like tenascin and fibronectin. Cholesteatoma shows significant changes in the ECM, supporting the view of a disturbed cell-matrix interaction. The purpose of our present study was to evaluate the distribution of TGF-beta in comparison to the deposition of tenascin, fibronectin, and collagen as major components of the ECM in cholesteatoma (n = 12) by means of histochemistry and immunohistochemistry. We found TGF-beta in lymphocytes and fibrohistiocytes in the stroma of 7 cholesteatomas. In corresponding sections, a marked expression of tenascin and fibronectin was seen manifesting as a continuous band along the epidermal-stromal junction, extending to the deeper stroma. In addition, in those cases of TGF-beta expression, beginning collagen fibril formation was seen in adjacent deeper stroma layers, indicating beginning stromal fibrosis. These results suggest that TGF-beta may be involved in the stimulation of the synthesis of tenascin, fibronectin, and collagen. Furthermore, the enhanced expression of tenascin and fibronectin provides evidence for a deregulated cell-matrix interaction in cholesteatoma associated with the enhanced proliferative process of cholesteatoma formation.

Overexpression of tenascin in cholesteatoma and external auditory meatal skin compared to retroauricular epidermis

In the present study the distribution of tenascin in cholesteatoma was immunohistochemically investigated. The results were compared with those in external auditory meatal skin and in retroauricular skin of healthy controls. The staining pattern was additionally correlated to the degree of cell proliferation as detected by the monoclonal antibody MIB-1 (Ki-67 antigen). Retroauricular skin showed a limited distribution of tenascin in the papillary dermis and a sparse reactivity of MIB-1 in only a few epithelial cells. External auditory meatal skin revealed a more pronounced reaction for tenascin and MIB-1. In contrast, cholesteatoma tissue exhibited an abundant and continuous expression of tenascin covering the whole stroma compartment. This coincided with a significant increase of MIB-1-positive cells in the basal and suprabasal epithelial layers. Doublestaining experiments revealed most prominent stromal tenascin-expression in areas with marked signs for epithelial proliferation. This suggests that tenascin is selectively increased in response to epidermal hyperproliferation. This matrix protein thus shows a quantitatively and qualitatively enhanced expression under pathological conditions. Moreover, the abundant reactivity for tenascin in the cholesteatoma provides evidence of a deregulated cell-matrix interaction involved in the hyperproliferative process of cholesteatoma formation.

[Intra-arterial cisplatin and sequential radiotherapy. Long-term follow-up]

BACKGROUND

The objective of this study was to improve the results of irradiation by prior application of intraarterial (i.a.) chemotherapy with cisplatin.

METHODS

Sixty-three patients suffering from advanced head and neck cancer without previous treatment were prepared for intraarterial chemotherapy by neck dissection without resection of the primary tumor and by modification of the carotid artery by creating a more inferiorly positioned bifurcation to facilitate intermittent i.a. infusion. The patients received approximately 400 mg cisplatin over a period of four to five weeks followed by irradiation with 60Co (64 Gy HD).

RESULTS

The survival rate at five years in all patients with adequate i.a. chemotherapy was 19 of 49 (39%), except those with adenoid-cystic carcinoma, who had a five-year-survival rate of 100%.

CONCLUSION

The results indicate that inductive i.a. chemotherapy with cisplatin has a positive influence on the outcome of irradiation even in inoperable head and neck cancer, which is defined by a longer period of remission with the possibility of curing the disease.

High levels of fibronectin in the stroma of aural cholesteatoma

PURPOSE

Because abundant fibronectin deposition is a hallmark of healing cutaneous wounds and provides a matrix for hyperproliferative and migratory epidermal cells, the distribution of fibronectin in aural cholesteatoma was investigated immunohistochemically.

MATERIALS AND METHODS

A monoclonal antibody against the major cell binding domain of human fibronectin was used to stain 4-micron cryosections of cholesteatoma tissue by the alkaline phospatase-antialkaline phosphatase method. Section of normal retroauricular skin served as control.

RESULTS

When processed in parallel, fibronectin staining was much stronger in the stroma of cholesteatoma than in normal dermis. The squamous epithelium of both tissues did not show any staining for fibronectin.

CONCLUSIONS

These observations lend support to the view that the growth of cholesteatoma epithelium reflects an aberrant regenerative process.

[Autocrine growth mechanisms of cholesteatoma epithelium]

Transforming growth factor alpha (TGF alpha) and interleukin 1 alpha (IL-1 alpha) are known to be produced by normal human keratinocytes stimulating their proliferation. The distribution and expression of TGF alpha and IL-1 alpha were examined in specimens of middle ear cholesteatoma by means of immunohistochemical methods using a monoclonal antibody against TGF alpha and a polyclonal one against IL-1 alpha. Normal retroauricular skin was stained for comparison. Staining for TGF alpha was consistently stronger in cholesteatoma epithelium than in normal epidermis, and encompassed all epithelial cell layers. Immune cells occurring in the stroma of cholesteatoma also reacted positively for TGF alpha. The intensity of staining for IL-1 alpha was markedly stronger in cholesteatoma tissue than in normal epidermis. All cellular layers of the squamous epithelium of cholesteatoma stained strongly and uniformly for IL-1 alpha, whereas the keratin layer was negative for IL-1 alpha. In the connective tissue beneath the cholesteatoma epithelium intensely positive cells were scattered between negative stromal cells. These data are consistent with autocrine stimulation of the squamous epithelium of cholesteatoma by TGF alpha and IL-1 alpha as well as with a paracrine stimulation by immune cells. Both factors contribute to the unrestrained growth of cholesteatoma in the middle ear cavity.

[New aspects on the pathogenesis of cholesteatoma: the possible role of immune cell-induced keratinocyte hyperproliferation]

Cholesteatoma of the middle ear consists of keratinising squamous epithelium in the middle ear cavity. Many points of the pathogenesis of cholesteatoma seem to be related to immune cell infiltrates in stroma and to epithelial cell migration and proliferation. In our study we found that the vast majority of cells infiltrating the stroma consisted of T-cells and macrophages, showing an immunologically activated state. Furthermore, the cholesteatoma epithelium showed an enhanced simultaneous expression of keratine-16 and Ki-67 positive cells. This expression was accompanied by the over-expression of transforming growth factor (TGF)-alpha, and its receptor, epidermal growth factor receptor (EGF-R) and interleukin-1, suggesting that the proliferation of keratinocytes could be stimulated in an autocrine manner. Finally, we conclude that the presence of immunologically activated immune cells in the stroma may be responsible for keratinocyte dysregulation in cholesteatoma epithelium.

Hyperproliferation-associated keratin expression in human middle ear cholesteatoma

Cholesteatoma is characterized by the presence of a squamous epithelium invading the middle ear altering its growth properties. This epithelium is believed to have hyperproliferative properties. Keratin 16 is accepted as a molecular marker for hyperproliferative epithelia. Two monoclonal antibodies K8.12 (directed against keratin 13) and KS.1A3 (directed against keratin 13 and 16) were used in an alkaline phosphatase anti-alkaline-phosphatase (APAAP)-technique to compare the expression of both keratin 13 and keratin 16 in normal human skin and aural cholesteatoma. Furthermore, the cytokeratin expression was compared to that of normal skin and palatine tonsil using one-dimensional gel electrophoresis. For both monoclonal antibodies, normal ear skin was stained only in the basal layer. In contrast, in the cholesteatoma samples the immunostaining of the antibody KS-1A3 was done not only in the basal cell layer but also in the suprabasal cells of the stratum spinosum and stratum granulosum. Using gel-electrophoresis, the presence of cytokeratin 16 was demonstrated in the cholesteatoma samples only. These results support the hyperproliferative character of cholesteatoma epithelium.

Aberrant expression of epidermal growth factor receptor in aural cholesteatoma

A monoclonal antibody recognizing an epitope of the external domain of the human epidermal growth factor (EGF) receptor was used in an alkaline phosphatase-antialkaline phosphatase (APAAP) technique to compare the distribution of this protein in normal human skin and aural cholesteatoma. EGF receptors appear to be highly expressed on the basal layer of the epidermis, in hair follicle apocrine sweat glands, and in the capillary system of normal skin. Cholesteatoma epithelium showed increased positive reactions in the suprabasal layers. A heterogeneity in the expression was found in different parts of the cholesteatoma. These results suggest the presence of an aberrant regulation and persistence of EGF receptors in cholesteatoma and confirm the hyperproliferative character of the cholesteatoma epithelium.

[Hyperproliferation-associated keratin 16 expression in cholesteatoma]

The position of a cell in a stratified squamous epithelium correlates with its state of differentiation as well as with the expression of certain cytokeratins. By means of both immunohistochemistry using the APAAP method and high resolution one-dimensional gel electrophoresis, specimens of cholesteatoma epithelium and normal ear skin were investigated whether they contain keratin 16 (K 16) which is known to be a marker of hyperproliferation. It could be shown that K 16 is expressed in all layers of cholesteatoma epithelium. Further to prove this fact gel electrophoresis was used showing a protein band at the localization of keratin 16. Hence, cholesteatoma can be seen as a locally hyperproliferative disease.

Possible role of interleukin 1 alpha and interleukin 1 beta in the pathogenesis of cholesteatoma of the middle ear

Cholesteatoma of the middle ear is characterized by the presence of hyperproliferative keratinizing squamous epithelium in the middle ear cavity and destruction of adjacent bone. Interleukin 1 (IL-1) is an autocrine growth factor for normal keratinocytes and is capable of inducing bone degradation. The distribution of two molecular species of IL-1, IL-1 alpha and IL-1 beta, was investigated immunohistochemically in the hyperproliferative epithelium of cholesteatoma, in normal epidermis of the auditory canal and of the retroauricular region, and in nonkeratinizing tonsillar epithelium. In all squamous epithelia examined, IL-1 alpha and IL-1 beta were present in comparable amounts. The IL-1 content of cholesteatoma epithelium was clearly increased in relation to normal skin keratinocytes. All cellular layers of cholesteatoma epithelium stained strongly and uniformly for Il-1 alpha and IL-1 beta, whereas the keratin layer was negative for IL-1. No particularly strong reaction with basal cells was detected. In the connective tissue under the squamous epithelium of cholesteatoma, intensely positive cells were scattered between negative stromal cells. Our results suggest that IL-1 could be liberated from disintegrating keratinocytes and cells of the monocyte-macrophage lineage, stimulate the proliferation of the cholesteatoma epithelium in an autocrine manner, and contribute to the enhancement of bone destruction in the presence of cholesteatoma.

[Interleukin-1-containing cells in cholesteatoma of the middle ear]

Cholesteatoma of the middle ear and the adjacent temporal bone consists of hyperproliferative keratinizing squamous epithelium in the middle ear cavity, and is capable of destroying the bone. Interleukin-1 (IL-1), an autocrine growth factor for epithelial keratinocytes, is characterized by its capacity to initiate bone absorption. Using immunohistochemical methods, the distribution of two different species of interleukin, IL-1 alpha and IL-1 beta, in cholesteatoma tissue (Fig. 2), the skin of the external ear canal, and the retroauricular region was investigated (Fig. 1). Comparable amounts of both IL-1-species were found in all squamous epithelia examined, but interleukin in cholesteatoma epithelium was increased in comparison with normal epidermis. All cellular layers stained uniformly and equally strongly for IL-1 alpha and IL-1 beta, whereas the dead cells of the keratin layer were negative for both. Some intensely stained cells were found scattered in the connective tissue underlying the basal layer of the cholesteatoma (Fig 4). Using double staining techniques these cells were shown to be mainly macrophages (Fig 6). Our results suggest that IL-1 could be liberated from disintegrating keratinocytes and cells of the monocyte-/macrophage lineage, and stimulate the proliferation of the cholesteatoma epithelium in an autocrine manner, thus contributing to the increased bone destruction seen in cholesteatoma.

Immunotype findings in macrophages in aural cholesteatomas

Since a heavy cellular infiltrate is seen in the stroma of most aural cholesteatomas, we attempted to characterize this cell population in more detail using monocyte/macrophage-specific monoclonal antibodies. KiM1 + (specific for CD11c antigen, the 150 kDa alpha-chain of a leukocyte integrin), and KiM6+ phagocytes were present in two- or fourfold higher numbers in the stroma of the six excised cholesteatomas than in the control tissues. Since the stroma of the cholesteatoma is devoid of microvessels, the typical perivascular localization of dermal macrophages was not seen in the cholesteatomas studied. The density of the macrophages in the normal ear skin was much higher in the upper dermis than in the lower dermis. In the cholesteatomatous specimens, the phagocytes were evenly scattered within the connective tissue and the cellular infiltrate. In contrast to diseased skin, no Mac 387+ macrophages were detected in the cholesteatomas. A great number of phagocytic cells closely resembling dermal macrophages was found in the stroma of the cholesteatomas and probably contributes to an active autoimmune process.

[Immunohistochemical identification of cholesteatoma-associated macrophage populations]

Extensive bone resorption occurring in aural cholesteatoma is responsible for the severe complications of this disease. In the area of active bone destruction, typical multinucleated osteoclasts are rarely seen, but a heavy cellular infiltrate is found. In the present study we tried to characterize the immunophenotype and the functional state of the cells infiltrating the stroma and the epithelial layer of aural cholesteatoma, using a panel of monoclonal antibodies directed against cell type specific antigens. The results were compared with normal retroauricular skin. The vast majority of cells infiltrating the stroma was bone marrow derived and consisted of T-cells and macrophages. By means of the activation markers HLA-DR and Interleukin-2 receptor an immunologically activated state of the majority of infiltrating cells in cholesteatomas was shown. The great number of activated macrophages in cholesteatomas seems to be very important in the cholesteatomatous immunological process. Because of their various immunological functions (antigen presentation to T-lymphocytes, participation in ingestion and killing of different invading microorganisms and synthesizing a great number of substances involved in host defence and inflammation) these cells play a central role in human immunological system. Langerhans cells, however, did not appear to be involved in the immune process of cholesteatoma. The characteristics of the infiltrating cell population with the great number of phagocytic cells suggest an active immune process resulting in autoaggressive bone resorption.

Phase I trial of a cisplatin-albumin complex for the treatment of cancer of the head and neck

1. A phase I trial of a cisplatin-albumin complex for the treatment of end-stage squamous cell carcinoma of the head and neck is reported. The complex was prepared by overnight incubation of cisplatin with human albumin at 37 degrees C. This resulted in more than 98% of the drug being bound to protein at the start of treatment. The patients were either unable to continue with or had refused conventional therapy with cisplatin. 2. The trial began at a dose of 100 mg cisplatin m-2 and was increased in 25 mg m-2 increments to 650 mg m-2. Despite the absence of the customary protective measures of pre-hydration and anti-emetic treatment no serious toxicity was encountered. 3. Unbound plasma platinum concentrations were lower than after conventional cisplatin treatment but total plasma platinum and tumour platinum concentrations were much higher. Urinary excretion of platinum was low and the incidence of nephrotoxicity was greatly diminished. Two responses were seen (one complete and one partial) in 38 patients treated and the median survival time was 109 days, compared with 151 days for patients treated conventionally with cisplatin and 56 days for untreated patients. 4. The complex is not as effective as conventional cisplatin therapy but is much less toxic, offers improved quality of life during treatment and may prove to be of benefit in patients who could not otherwise be treated.

Immunologically activated cells in aural cholesteatoma

In this immunohistochemical study, we characterized the cells infiltrating the stroma of acquired aural cholesteatomas in detail, using a panel of monoclonal antibodies directed against immune cell type-specific antigens, HLA class II antigens, and interleukin-2 receptor. For all antibodies used, normal ear skin was stained for comparison. The vast majority of the infiltrating cells was CD45-positive, ie, derived from bone marrow. Reactivity with anti-CD3 and anti-CD6 antibodies revealed an abundant infiltration of T lymphocytes beneath the squamous epithelium of cholesteatoma. The B lymphocyte-specific anti-CD19 and anti-CD22 antibodies detected only occasional positive cells. Hence, the cellular infiltrate in the stroma of aural cholesteatoma is made up primarily of T cells with macrophages scattered between them. Expression of HLA-DR was almost as high as that of CD45, whereas CD25-positive cells were detected in lower amounts. We infer that the majority of T cells and macrophages in the stroma of cholesteatoma are in an immunologically activated state. The characteristics of the infiltrating cell population suggest an antigen-driven process in cholesteatoma.

[Rupture of the trachea during difficult intubation]

Serious injuries of the larynx or trachea during tracheal intubation are rare but potentially life-threatening complications. This case report describes the diagnostic procedures and therapeutic management of an intubation-induced tracheal rupture in a young female patient with a musculoskeletal disorder (rigid spine syndrome). Interdisciplinary treatment requires precise documentation of the extent of the injuries, including advanced imaging techniques. Removal of the endotracheal tube prior to accurate diagnosis can result in immediate airway obstruction. Because of the risk of infection, as a rule surgical treatment is indicated.

[Endoscopic controlled laser lithotripsy in the treatment of sialolithiasis]

The article describes the first successful application of endoscopically controlled laserlithotripsy in the ENT field in a patient with recurrent purulent sialadenitis of the left submandibular gland due to sialolithiasis. By means of endoscopically controlled laserinduced lithotripsy of salivary gland stones, it was possible to achieve complete stone fragmentation without harming the glandular duct and the gland.

[Infusion systems for intra-arterial chemotherapy]

A short description of the standard devices with extra-corporal or intracorporal pumps is followed by a description of a new extracorporal pump. Since the new pump is independent of electric mains supply, it is more comfortable for the patient, who can walk around even during intraarterial infusion. However, as the flow rate of the pump is low, very thin catheters have to be used to avoid clotting caused by blood reflux within the catheter.

[Objective gustometry with adequate stimulation by registration of contingent negative variation]

Cortical evoked potentials require a steep and temporally reproduceable onset of sensory stimulation. As both items are difficult with gustatory stimuli, we tried to record the slow expectancy potential or "contingent negative variation" (CNV), which has turned out to be useful in objective olfactometry and speech audiometry. Sour, sweet, bitter or salty fluids were embedded in a water stream, which was sucked through a device well fitting to the tongue with holes at adequate locations. The negative vertex potential developped reproduceably between the recognition of taste and the acoustic signal, which could be expected only after one of the two alternatively offered gustatory stimuli. Clinical use of the method is demonstrated in a case of asymmetric loss of smell due to interruption of the chorda tympani during cholesteatoma operation. The CNV appeared only when stimulating the side of the tongue opposite to the ear operated on. In addition to the total or unilateral loss of taste, the ability to differentiate between two gustatory qualities can be diagnosed with an objective method, provided the patient cooperates by calm and attentive behaviour.

Transformation of the structure of collagen. A time-resolved analysis of mechanochemical processes using synchrotron radiation

Mechanochemically induced molecular transformations of collagen fibres were analysed using time-resolved small-angle diffraction spectra and histomechanical measurements. In particular, the influence of aqueous and methanolic perchlorate solutions was examined. According to a transformation continuing from the periphery towards the centre, the macroscopic contraction that is completed less than five minutes after incubation with perchlorate is caused by peripherally transformed fibrils only, whereas the centrally situated fibrils first undergo an accordion-like folding, but after more than 20 minutes are transformed similarly. The triple-helical transformation is preceded by a structure-breaking effect on structural water that can be monitored in time-resolved diffraction spectra. The combined loss of meridional low-angle reflections and cross-striated fibrils in micrographs is irreversible. By dialysis of colloidally dissolved collagen against a solution of ATP, however, segment-long spacing aggregates are obtained. Under isometric conditions, an instantaneous transformation of intermittent regions leads to an increase in the long period of adjacent, still structured regions of the same fibril that is correlated with a delayed increase in tension in the fibre. Increase of tension under isometric conditions as well as the flow-properties of a fibre relaxed in perchlorate are interpreted in terms of the parallel sliding of subunits of varying lengths, which has been demonstrated by diffraction analysis.

[The value of computer tomography in the diagnosis of congenital spinal malformations particularly diastematomyelia (author's transl)]

The value of computer tomography (CT) in the diagnosis of diastematomyelia (DM) was studied in our own clinical material. Thirty-one patients with congenital spinal anomalies were examined; in 21 a DM could be demonstrated. CT has two major advantages in the radiological investigation of spinal abnormalities, such as spinal dysraphism and DM: 1. Cross sections of the spinal canal can be obtained without overlying opacities and 2. The demonstration of intraspinal soft tissues structures, corresponding to their attenuation characteristics and the relative differences in absorption of the x-rays.