W. Schweiger

Local nitroglycerin for treatment of anal fissures: an alternative to lateral sphincterotomy?

PURPOSE: Nitric oxide is an important neurotransmitter mediating internal anal sphincter relaxation. Patients suffering from fissure-in-ano were treated with topical nitroglycerine. The clinical evidence for therapeutic adequacy was examined in a prospective, randomized study. METHODS: The study included 35 patients with acute and chronic anal fissures. In Group A, including 20 patients with the clinical diagnosis of acute (12 patients) and chronic (8 patients) anal fissures, treatment consisted of topical nitroglycerine. Group B, consisting of 15 patients (10 acute and 5 chronic fissures), received topical anesthetic gel during therapy. Manometry was performed before and on days 14 and 28 in the course of topical application of either 0.2 percent glyceryl trinitrate ointment or anesthetic gel (lignocaine). Anal pressures were documented by recording the maximum resting and squeeze pressures. RESULTS: In 60 percent of cases treated with topical nitroglycerine (Group A, 11 acute (91.6 percent) and 1 chronic (12.5 percent)), anal fissure healed within 14 days, in contrast to Group B in which no healing was observed. The healing rate after one month was 80 percent (11 acute (91.6 percent); 5 chronic (62.5 percent)) in Group A and was significantly superior to Group B (healing rate, 40 percent: 5 acute (50 percent); 1 chronic (20 percent)). DISCUSSION: Previously increased maximum resting pressures decreased from a mean value of 110 to 87 cm H2O. This represents a mean reduction of 20 percent (P=0.0022). We also noted a significant decrease in squeeze pressures (from 177.8 to 157.9 cm H2O (11 percent)). However, anal pressures did not decrease significantly in the four chronic fissure patients from Group A, whose fissures only healed after 28 days. Similarly to these Group A chronic fissure patients, no significant anal pressure reduction was observed in any Group B patients. Except for mild headache (20 percent), no side effects of treatment were reported. CONCLUSIONS: Topical application of nitroglycerine represents a new, easily handled, and effective alternative in the treatment of anal fissures. All of our patients reported a dramatic reduction in acute anal pain. However, it should be noted that a lack of sphincter tone reduction is a likely reason for the great tendency of chronic anal fissures to recur.

Witten index, axial anomaly, and Krein’s spectral shift function in supersymmetric quantum mechanics

A new method is presented to study supersymmetric quantum mechanics. Using relative scattering techniques, basic relations are derived between Krein’s spectral shift function, the Witten index, and the anomaly. The topological invariance of the spectral shift function is discussed. The power of this method is illustrated by treating various models and calculating explicitly the spectral shift function, the Witten index, and the anomaly. In particular, a complete treatment of the two‐dimensional magnetic field problem is given, without assuming that the magnetic flux is quantized.

Commutation methods applied to the mKdV-equation

An explicit construction of solutions of the modified Korteweg-de Vries equation given a solution of the (ordinary) Korteweg-de Vries equation is provided. Our theory is based on commutation methods (i.e., N = 1 supersymmetry) underlying Miuras transformation that links solutions of the two evolution equations.

Cystic adventitial degeneration of the popliteal artery — the diagnostic value of duplex sonography

Cystical adventitial degeneration of the popliteal artery is a disorder which is difficult to diagnose, due to the similarity of the symptoms of people presenting with peripheral arterial occlusive disease (PAOD) or popliteal entrapment syndrome. The only thing that differs from patients suffering from PAOD is the lack of typical risk factors for arteriosclerosis. Typical diagnostic procedures like conventional angiography or magnetic resonance Imaging angiography can be negative, too and therefore misleading. The only which is crucial in the diagnosis of cystic adventitial degeneration of the popliteal artery is to know the morphological background of this disorder, namely that it is a cyst of the adventitia of the artery which leads to a dynamic exercise-dependent flow inhibition. We present a 57-year old white male who had a weeks history of intermittent claudication in his left calf. He was lacking of typical risk factors for arteriosclerosis and on first examination all pulses in both lower extremities were palpable and Doppler index on both legs was >1. Only duplexsonography revealed a cystic formation impressing the left popliteal artery in the hight of the rift in the popliteal joint.

On exclusive reactions in the time-like region☆

Abstract The electromagnetic form factors of the proton in the time-like region and two-photon annihilations into proton-antiproton are investigated. To calculate these processes at moderately large s we use a variant of the Brodsky-Lepage hard-scattering formalism where diquarks are considered as quasi-elementary constituents of baryons. The proton wave function and the parameters controlling the diquark contributions are determined from fits to space-like data. We also comment on the decay ν c → p p .

Exclusive production of heavy flavours in proton-antiproton annihilation

Abstract Annihilation of p p into two hadrons, requiring the production of at least one heavy valence quark pair (i.e. s s , c c , b b ), is investigated within a constituent scattering model. Besides quarks we allow for diquarks as quasi-elementary constituents of baryons. The flavour changing processes on the constituent level thus are quark-antiquark (diquark-antidiquark) annihilation and subsequent creation through one gluon. The non-perturbative formation of the constituents to hadrons is described by flavour dependent relativistic wave functions. The calculated cross sections for various hyperon channels compare very well with experiment. For charmed and bottomed two hadron channels (like Λ c Λ c , D + D − , Λ b Λ b , B + B − , etc.) we give estimates of cross sections indicating the measurement of exclusive charmed hadron pairs to be feasible at a future facility like e.g. SuperLEAR.

Analysis of low-energy antiproton-proton forward scattering

Abstract Based on previous analyses of forward p p and pp scattering within the dispersion theoretical approach we have investigated p p scattering making use of new experimental information from LEAR and the CERN p p collider. The main interest is focused on the low-energy region although the high-energy region is also discussed briefly. We present a rather natural explanation of the peculiar features of the LEAR data on the ρ parameter. Moreover, we address ourselves to the problems of Coulomb contamination of the data, the normalizations and the extraction of the p p scattering length from line shifts and widths of the p p atom. These effects are estimated using a simple optical model appropriately designed for the low-energy region.

A diquark model for proton-antiproton annihilation into hyperon-antihyperon☆

Abstract We propose a constituent scattering model for p p → Y barY in which, besides quarks, disquarks act as (quasi-) elementary constituents of baryons. The elementary scatterings are quark and diquark annihilation and creation respectively through one gluon. With broken SU(6) wave functions we are able to calculate cross sections for various hyperon channels and to predict spin parameters. The results, e.g. magnitude and energy dependences of cross sections, are in excellent agreement with data. Particularly noteworthy is the fact that in contrast to other authors we can also treat channels such as Σ − Σ + which can only proceed through diquark annihilation.

Hard exclusive baryon-antibaryon production in two-photon collisions

Abstract. We study baryon pair production in two-photon collisions,

TWO-PHOTON ANNIHILATION INTO PROTON-ANTIPROTON IN A QUARK-DIQUARK SCHEME

\gamma \gamma \rightarrow B \bar{B}