How to probe high gluon densities in pp collisions at the Large Hadron Collider.

We present a model for hadron production in the proton fragmentation region in pp collisions at the CERN Large Hadron Collider which accounts for the first time for effects of very strong small x gluon fields. Average transverse momenta acquired by the valence quarks exceed 1 GeV/c for central collisions and result in the suppression of leading baryon production and an additional energy flow to smaller rapidities. A strong dependence on the impact parameter will allow one to investigate the propagation of leading partons through gluon fields of a strength comparable to the ones encountered in heavy ion collisions at the LHC and in cosmic-ray-air interactions at highest energies.

High-density QCD and cosmic-ray air showers.

We discuss particle production in the high-energy, small-x limit of QCD where the gluon density of hadrons is expected to become nonperturbatively large. Strong modifications of the phase-space distribution of produced particles as compared to leading-twist models are predicted, which reflect in the properties of cosmic-ray induced air showers in the atmosphere. Assuming hadronic primaries, our results suggest a light composition near Greisen-Zatsepin-Kuzmin cutoff energies. We also show that cosmic-ray data are sensitive to various QCD evolution scenarios for the rate of increase of the gluon density at small x, such as fixed-coupling and running-coupling Balitsky-Fadin-Kuraev-Lipatov evolution. There are clear indications for a slower growth of the gluon density as compared to RHIC and HERA, due, e.g., to running-coupling effects.

Novel mechanism of H0 dibaryon production in proton-proton interactions from parton-based Gribov-Regge theory.

A novel mechanism of H0 and strangelet production in hadronic interactions within the Gribov-Regge approach is presented. In this approach the H0 is produced by the same mechanism as usual hadrons, namely, by disintegration of the remnant formed by the exchange of pomerons between the two protons. Rapidity and transverse momentum spectra of the observed hadrons are well described in this approach. In contrast to traditional distillation approaches, here the production of multiple (strange) quark bags does not require large baryon densities or a quark gluon plasma. We calculate the rapidity and transverse momentum distributions as well as the 4pi multiplicity of the H0 for sqrt[s]=17 GeV (Super Proton Synchrotron) and 200 GeV (Relativistic Heavy Ion Collider). In both cases the H0, if it exists, should be observable by the present experiments.

Self-consistency requirement in high-energy nuclear scattering.

Practically all serious calculations of exclusive particle production in ultrarelativistic nuclear or hadronic interactions are performed in the framework of Gribov-Regge theory or the eikonalized parton model scheme. It is the purpose of this paper to point out serious inconsistencies in the above-mentioned approaches. We demonstrate that requiring theoretical self-consistency reduces the freedom in modeling high-energy nuclear scattering enormously, and we introduce a fully self-consistent formulation of the multiple-scattering scheme in the framework of a Gribov-Regge--type effective theory. In addition, we develop new computational techniques which allow for the first time a satisfactory solution of the problem in the sense that calculations of observable quantities can be done strictly within a self-consistent formalism.

[Arthroscopic resection of the shoulder joint (Mumford operation)]. / Arthroskopische Resektion des Schultergelenkes (Mumford-Operation).

Based on results of anatomical studies, we established an arthroscopic procedure to resect all degenerative changes within the joint without endangering the stabilizing structures. Since November 1989 we operated on 26 patients with this technique. There were no major complications. The mean score significantly increased from 64.9 (+/- 12.8) to 86.8 (+/- 11.5). Analysis of postoperative x rays revealed an average length of resection of 21.3 mm at the inferior border of the clavicle, of 15.4 mm in the middle, and of 10.2 mm at the superior border of the clavicle. 21 out of 26 patients were completely satisfied and would undergo the same procedure again. In two of the five unsatisfied patients the resected length of the clavicle was insufficient and these patients required open surgery for resection of the remaining bone. Our first experiences are encouraging. The surgical technique is standardized and reproducible. The short time results score not worse compared to the open conventional technique. With the 2 to 4 year long term follow up we have to prove, whether maintaining the passive stabilizers of the joint improves the long term results better than the open technique.

[The risk of neurovascular damage in elbow joint arthroscopy. Which approach is better: anteromedial or anterolateral?]. / Das Risiko Neurovaskulärer Schädigungen bei der Ellenbogengelenkarthroskopie. Welcher Zugang ist günstiger: Anteromedial oder Anterolateral?

In a cadaver dissection study the relation of the arthroscopic portals to the neurovascular structures was documented. In six cadaveric elbows the capsule was distended with 35-40cc fluid of 0.9% NaCl by using the direct lateral portal. An anterolateral and anteromedial approach to the elbow joint were established. The distance of the arthroscopic portals to the neurovascular bundles were measured at empty and filled joint after performing an anatomic dissection. The influence of flexion and extension of the joint as well as pronation and supination of the forearm on the distance of the arthroscopic sheath to the neural structures was documented. Lesions of the superficial cutaneous nerves were not seen. Using the anterolateral portal in the best position of the joint (90 degrees flexion and not distended joint at max. pronation of the forearm) we measured a proximity of 4.5 mm (range 2-10 mm) to the radial nerve. For the anteromedial approach the mean distance of the median nerve to the arthroscopic sheath was 15.5 mm (range 8-27 mm), when the optimal joint position was used (90 degrees flexed joint, distended, max. supination of the forearm).

[Current concepts in treatment of the unstable shoulder. Results of a countrywide survey]. / Aktuelle Konzepte bei der Behandlung der instabilen Schulter. Ergebnisse einer bundesweiten Befragung.

The object of the study was to evaluate the management of patients with acute or recurrent shoulder instabilities. Therefore all trauma, general surgery, and orthopaedic departments in Germany were asked to complete a standardized evaluation form; completed questionnaires were returned from 880 institutions treating shoulder instabilities. Questions were asked about the diagnostic imaging techniques used and about conservative and operative treatment. In addition, the treatment regimens that would be followed for two typical patients were asked for. In patients with shoulder instabilities the following diagnostic imaging techniques were used: X-ray (97.1%), ultrasound (61.3%), CT (29.1%), arthro-CT (26.2%), MRI (13.3%), arthrography (24.1%), and arthroscopy (30.6%). After the first traumatic dislocation the average period of immobilization was 2.2 weeks. Immobilization was achieved with a sling in 2.0%, with a Desault bandage in 38.8%, with a Gilchrist bandage in 72.7%, and with a cast in 4.2% of cases. Open surgical stabilization was performed according to Bankart (30%), Eden-Hybinette (28.6%), Weber (Osteotomy) (27.1%), Lange (15.5%), Putti-Platt (13.6%), and other procedures (Magnusson-Stack, Bristow) only occasionally. The average period of immobilization after open surgery was 3.0 weeks. Arthroscopic stabilization techniques were applied by 7.5%. In a 19-year-old handball player stabilization would be performed immediately after the first traumatic dislocation in 9.2% of the institutions; in 34.4% the patient would not be operated on, and in 56.3% the shoulder would be stabilized after the third redislocation.(ABSTRACT TRUNCATED AT 250 WORDS)

[Magnetic resonance morphologic changes in shoulder joints of world class water polo players]. / Kernspinmorphologische Veränderungen an Schultergelenken von Weltklasse-Wasserballspielern.

UNLABELLED: In a prospective study we examined the dominant shoulder of 11 athletes from the 1992 German Olympic water polo team. Their mean age was 25.4 +/- 3.5 years. Water polo had been practised generally for 14.1 +/- 4.3 years and professionally for 11.6 +/- 3.9 years. The weekly training amounted to between 12.5 and 19.5 hours. All athletes were submitted to standardised clinical, sonographical and MRI tests. In 5 cases we found anamnestic and/or clinical indications of rotator cuff pathology. In all 5 cases the supraspinatus tendon was affected, and in three cases both the supra- and the infraspinatus tendon were involved. Sonographically, no specific pathology except a thickened rotator cuff was seen. Remarkable changes were revealed by magnetic resonance imaging. In 8 cases changes were present in the insertion of the rotator cuff at the humeral head. The subacromial bursa was not pathologic. The tendon of the long head of the biceps was pathologically changed in 9 cases. In 7 athletes a so-called biceps halo and in two an osteophyte in the area of the bicipital groove was visible. In all of the 11 dominant shoulder joints massive hypertrophy of the articular capsule and pathologic changes of the anterior glenoid labrum existed. Occult osseous lesions were detected in 5 athletes, and osseous lesions of the humeral head in 8 athletes. In all athletes we could document degenerative changes at the acromioclavicular joints such as effusion in 7 cases, arthritis in two cases, and evident synovitis in two cases. CLINICAL RELEVANCE: Many of the changes detected by MRI were not symptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

[Chlamydia and mycoplasma infections in men of couples with involuntary sterility]. / Chlamydien- und Mykoplasmeninfekte bei Männern von Paaren mit unfreiwilliger Kinderlosigkeit.

There is conflicting evidence on the influence of infections with Chlamydia trachomatis and Mycoplasma hominis on male and female infertility. We studied the prevalence of Chlamydia and Mycoplasma in male partners of 165 infertile couples. 25% of couples with tubal and/or andrological sources of infertility showed positive cultures for Chlamydia and/or Mycoplasma compared with 10% of couples with other causes of infertility. Our data suggest, that screening for Chlamydia and Mycoplasma in infertility patients may be of assistance.

[Sports therapy in Bechterew's disease--presentation of a new treatment concept]. / Sporttherapie bei Morbus Bechterew--Vorstellung eines neuen Behandlungskonzeptes.

Bechterew's disease is a chronic-inflammatory condition of the spine, with a tendency toward stiffening and relatively frequent involvement also of the hip, knee and shoulder joints. Contrary to most other rheumatic diseases, drug therapy plays a rather minor role. The focus is on movement, in line with the motto that "Bechterew patients need movement". The sports therapy concept of the Münster University Bechterew group as well as initial experience are set out.

Does the glenohumeral joint capsule have proprioceptive capability?

We performed a clinical study examining 60 volunteers with stable shoulder joints randomized to two groups. In group 1 we injected 5 ml lidocaine intra-articularly. In group 2 we injected 5 ml saline with 5 ml contrast dye the same way. After the injection we measured the amount of passive anteroposterior translation that occurred during anterior and posterior drawer tests and the amount of inferior subluxation during downward stress. We documented the extent of the passive glenohumeral translation using ultrasound. We had no complications related to the intra-articular injection or to the stability measurement. After the injection neither group had significant pain, and the patients were not apprehensive about the ensuing stability test. In group 1 (lidocaine) anteroposterior translation of 13.2 +/- 6.3 mm was seen in the anterior and posterior drawer test, whereas in group 2 (no lidocaine) the anteroposterior translation was only 6.8 +/- 3.2 mm. The difference between the two groups was statistically significant (P < 0.05). With downward stress during the sulcus test the distance between the acromion and the humeral head increased by 5.6 mm (+/- 3.2) in group 1 and by 2.7 mm (+/- 2.1) in group 2. This difference was also statistically significant (P < 0.05). Clinical consequences: Taking our preliminary findings into account, the capsule of the glenohumeral joint seems to have proprioceptive capability. Nerve fibres and mechanoreceptors seem to be localized in the capsule tissue, being part of a physiological feedback mechanism. If our conclusions proprioceptive capability. Nerve fibres and mechanoreceptors seem to be localized in the capsule tissue, being part of a physiological feedback mechanism.

[The place of magnetic resonance tomography in the diagnosis of diseases of the shoulder joint]. / Stellenwert der Magnetresonanztomographie in der Diagnostik von Schultergelenkerkrankungen.

In a prospective study 43 patients with shoulder pain were examined by sonography and MRI. The findings were controlled by plain radiography, arthrography, and CT arthrography. Joint effusions and humeral head defects were equally identified by MR and sonography. In the diagnosis of labrum lesions, rotator cuff lesions, subacromial spurs, and synovial inflammatory disease sonography was not as accurate as MR. A special MR scoring system improved the diagnosis of an impingement syndrome.

[Short rib-polydactyly syndromes]. / Short rib-polydactyly syndromes.

The authors report on a newborn which died only a few hours after birth. It manifested generalized dropsy and ascites, a central upper lip cleft, narrow thorax, severe dysraphia, short limbs but normal-length trunk, and brachydactyly. Particularly striking radiologic findings were the extremely short, horizontal ribs and a shortening of the long bones, with rounded calcification zones. On the basis of comparison with other cases of short rib-polydactyly syndromes (SRPS) and other chondrodysplasias, this case was classified as Majewski's syndrome, even though there was no polydactyly and the shortness of the tibiae was not as extreme as in typical cases.

[Influenza]. / Influenza.

Influenza is the last great uncontrolled plague of mankind. Pandemics and epidemics occur at regular time intervals. The influenza viruses are divided into the types A, B and C and show unique variability of their surface antigens (hemagglutinin and neuraminidase). Influenza viruses of type A show the largest degree of antigenic variation which, in turn, resulted in the definition of a number of subtypes, each comprising many strains. By comparison, influenza viruses of types B and C exhibit much less variation of their surface antigens. As a consequence, no subtypes but many different strains have been recognized. The degree of antigenic variation correlates with the epidemiologic significance of the virus types, type A being the most and type C the least important. Two different kinds of antigenic variation have been recognized: In the case of minor variation of one or both surface antigens, the term "antigenic drift" is employed. Antigenic drift occurs with all three types of virus, it is caused by point mutations which increase the chance of survival of mutants in the diseased host. In addition, influenza A viruses show sudden and complete changes of their surface antigens in regular time intervals, resulting in the appearance of new subtypes. This event is called "antigenic shift". The mechanisms responsible for antigenic shift are poorly understood, only. In addition to the recycling of preceding subtypes, reassortment resulting from double infection of cells with strains of human and animal origin are considered possible explanations. By use of modern DNA recombinant technology, the base sequences of a series of virus genes and, as a consequence, the amino acid sequence of the corresponding antigens have been determined. By means of monoclonal antibodies, the antigenic structure of many influenza antigens has been further elucidated. It can be expected that further research on the molecular basis of antigenic variation could finally result in an understanding of the causal mechanisms. It is an outstanding feature of the epidemiology of influenza A viruses that a family of related strains prevails for a certain period of time and disappears abruptly as a new subtype emerges.(ABSTRACT TRUNCATED AT 400 WORDS)

The fine structure of the parabronchi and the gas exchange area of the Adelie penguin lung.

The parabronchi of the Adelie penguin are endowed with wide atria forming pockets between a loose meshwork of bundles of smooth muscle cells lining the parabronchial lumen. The atrial epithelium is of variable thickness and bears numerous microvilli, which are overlain by/or embedded in sheets or whorls of lamellar material ("trilaminar substance", diameter of one lamella 8 ..10 nm) forming layers of very variable thickness. The cells contain either stacks or whorls of this material or roundish lamellated bodies, and are interconnected by desmosomal contacts as well as what presumably represent tight junctions. Underneath the epithelium and within the bundles of muscle cells regularly nerve fibres have been found. The diameter of the morphological air/blood barrier is about 165...210 nm in thin areas, excluding a 12...20 nm thick layer covering the luminal plasma membrane of the air capillary epithelium. The blood capillary endothelium ordinarily is markedly thicker (40...250 nm) than the air capillary epithelium (17...25 nm). The basal lamina between endo- and epithelium is a uniform structure measuring about 95...105 nm. The endothelial cells are interconnected by desmosomal and probably tight junctions.