Showing papers by "Heidelberg University published in 1973"

Toward a quantum theory of observation

Abstract: The program of a physical concept of information is outlined in the framework of quantum theory. A proposal is made for how to avoid the intuitive introduction of observables. The conventional and the Everett interpretations in principle may lead to different dynamical consequences. An ensemble description occurs without the introduction of an abstract concept of information.

Transanulare Wechselwirkungen bei [2.2]Phanen, II. Synthesen von [2.2](4,4′)Biphenylophan, [2.2](2,7)Phenanthrenophan und [2](4,4′)Biphenylo[2](2,7)phenanthrenophan

Abstract: [2.2](4,4′)Biphenylophan (1) und 5,6,17,18-Tetrahydro[2.2](2,7)phenanthreilophan (2) wurden aus den entsprechenden Disulfonen 7 bzw. 12 durch Dampfphasen-Pyrolyse (500°C, 0.1 Torr) erhalten. [2.2](2,7)Phenanthrenophan (3/4) entstand aus 2 durch Oxidation mit 2,3-Dichlor-5,6-dicyan-1,4-benzochinon. Die entsprechende Synthese des [2](4,4′)Biphenylo[2](2,7)-phenanthrenophans (5) aus 15 uber 16 zeigt die Eignung der Dampfphasen-Pyrolyse von Disulfonen auch zur Darstellung von [2.2]Phanen mit zwei verschiedenen Aromaten-Einheiten. NMR-, U V - und Massenspektren der dargestellten [2.2]Phane werden angegeben. - Ein zweistufiger Radikalmechanismus ist mit den experimentellen Befunden bei der Dampfphasen-Pyrolyse der Disulfone in Ubereinstimmung. Transanular Interactions in [2.2]Phanes, II. Syntheses of [2.2](4,4′)Biphenylophane, [2.2](2,7)Phenanthrenophane and [2](4,4′)Biphenylo[2](2,7)phenanthrenophane [2.2](4,4′)Biphenylophane (1) and 5,6,17,18-tetrahydro[2.2](2,7)phenanthrenophane (2) were synthesized from the corresponding disulfones 7 and 12, resp., by vapor phase pyrolysis (500°C, 0.1 Torr). [2.2](2,7)Phenanthrenophane (3/4) was obtained by oxidation of 2 with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. The analogous synthesis of [2](4,4′)biphenylo[2]-(2,7)phenanthrenophane (5) from 15via16 proves the applicability of this method for the preparation of [2.2]phanes with two different aromatic units. N.m.r., u.v., and mass spectra of the [2.2]phanes are reported. – A two-step radical mechanism is in accordance with the experimental results of the vapor phase pyrolysis of disulfones.

Spaltungsreaktionen des Trimethylsilylcyanids, eine neue Darstellungsmethode für O-(Trimethylsilyl)cyanhydrine

Abstract: Die Spaltung des Trimethylsilylcyanids mit Phosgen ergibt Tricyan(trimethylsiloxy)methan. Oxalyldichlorid reagiert zum 1,1,2,2-Tetracyan-1,2-bis(trimethylsiloxy)athan und Trifluoracetylchlorid zum Dicyan(trifluormethyl)(trimethylsiloxy)methan. Nicht nur Halogenatome werden gegen die Cyangruppe ausgetauscht, sondern auch die Carbonylgruppe reagiert mit Trimethylsilylcyanid analog der Cyanhydrinsynthese. Eine Anzahl typischer O-(Trimethylsilyl)cyanhydrine wurde erstmals dargestellt. Cleavage Reactions of Trimethylsilyl Cyanide, a New Synthesis of O-(Trimethylsilyl)-cyanohydrines The cleavage of trimethylsilyl cyanide with phosgene yields tricyano(trimethylsiloxy)methane. Oxalyl dichloride and trifluoroacetyl chloride react under formation of 1,1,2,2-tetracyano-1,2-bis(trimethylsiloxy)ethane and dicyano(trifluoromethyl)(trimethylsiloxy)methane, respectively. Not only halogen atoms are exchanged by the cyano group but also the carbonyl group reacts with trimethylsilyl cyanide analogously to the synthesis of cyanohydrines. A number of typical O-(trimethylsilyl)cyanohydrines was obtained for the first time.

On the genetics of the primary generalized epilepsy with sporadic myoclonias of impulsive petit mal type. A clinical and electroencephalographic study of 399 probands.

Abstract: 319 patients with impulsive petit mal and 390 family members of the probands were examined clinically, genetically and electroencephalographically. The results are as follows. 1. The incidence of probands with genetic predisposition was 27.3%, which was higher than that (9.9%) found in 466 non-selected epileptic patients at the same clinic. The incidence was higher in female than in male probands (33.5%:21%). 2. The incidence of epilepsy among near relatives was 4.1% and was higher among female than male near relatives (5.4%:2.9%), higher among mothers than fathers (4.7%:1.9%), and higher among daughters than sons (9.8%:1.8%), but varied only slightly between sisters and brothers (4.6%:4.2%). The incidence was highest in sons and daughters (5.1%), intermediate in siblings (4.4%) and lowest in parents (3.3%). The relatives of female probands showed a higher incidence than those of male probands (6.0%:2.0%). 3. Impulsive petit mal was found in 15% of the 116 epileptic relatives, awakening grand mal in 17% and absence in 14%. 4. EEG examination showed unspecific paroxysmal abnormalities in 40% and specific abnormalities in 15% of 390 family members, incidences significantly higher than those in the control subjects. Relatives of female probands showed a higher frequency of paroxysmal EEG abnormalities than that in male probands (61%:47%). Offspring were found to have the highest, siblings an intermediate and parents the lowest frequency of paroxysmal as well as specific EEG abnormalities. 5. Of 1618 near relatives 118 (7.3%) showed epileptic seizures and/or specific EEG abnormalities. The incidence was higher in female than in male relatives (9.3%:5.5%) and higher in relatives of female probands than those of male probands (9.3%:5.2%). Offspring showed the highest (13.8%, 17% in daughters and 12% in sons), siblings an intermediate (6.7%, 8% in sisters and 5% in brothers), and parents the lowest level (5.2%, 8% in mothers and 3% in fathers). 6. Correlation between the incidence of EEG abnormalities and age among relatives was analyzed. 7. Pedigree studies showed maternal preponderance. 8. No proband was found to be born of a consanguineous marriage. There were many sibship cases in which one parent at least was found to have specific or paroxysmal EEG abnormalities. 9. It was concluded that the mode of inheritance of impulsive petit mal is most probably polygenic. Our hypothesis is (1) the etiology of the illness is more genetic less environmental in female patients (greater heritability). (2) Female subjects have a lower threshold for manifestation. 10. In our sample, 55% of male and 65% of female patients were married. Both figures were lower than those (78% for males and 77% for females) in the general population. 11. The importance of family study is emphasized.

Human embryonic lung cells abortively infected with Herpes virus hominis type 2 show some properties of cell transformation.

Abstract: LATENT herpes virus infections are indigenous in man. The oncogenic properties of herpesviruses in vivo have been discussed1 and possible malignant transformation of hamster cells by herpes simplex virus has been shown2,3. Here we demonstrate that Herpesvirus hominis (herpes simplex virus; HVH) can abortively infect primary human embryonic lung (HEL) cells in vitro, and these cells subsequently acquire properties characteristic of transformed cells. Abortive infection is required for malignant transformation. The genetic properties of HVH were altered by partial inactivation by UV-irradiation and the lytic functions of the virus were inhibited, producing abortive infection and subsequent transformation2,8. We achieved inhibition of the HVH lytic functions after infection of a primary cell line derived from human embryonic lung by raising the incubation temperature of the cell cultures to 42° C after HVH infection.

Transanulare Wechselwirkungen bei [2.2]Phanen, III. [2,2](2,6)Naphthalinophan und [2.2](2,6)Naphthalinophan‐1,11‐dien

Abstract: Das chirale [2.2](2,6)Naphthalinophan 2 wurde ausgehend vom cyclischen Disulfid 7 uber das Disulfon 8 durch Dampfphasen-Pyrolyse synthetisiert. Die S-analoge Stevens-Umlagerung des aus 7 erhaltenen Bis-sulfoniumsalzes 10 ergab 12, aus dem uber 13 das [2.2](2,6)Naphthalinophan-1,11-dien 4 erhalten wurde. Bei diesen Synthesen war das Entstehen der achiralen Verbindungen 1 und 3 nicht nachzuweisen. Katalytische Hydrierung uberfuhrte 4 in 2. — Uber diastereomere Charge-Transfer-Komplexe mit (−)-2-(2,4,5,7-Tetranitro-9-fluorenyliden-aminooxy)propionsaure lies sich 2 in seine Enantiomeren trennen. Anhand sterischer Modelle der Komplexe wird fur (−)-;2 die S-Chiralitat vorgeschlagen. — Die spektroskopischen Eigenschaften von 2, 4 und den in der voranstehenden Arbeit1) beschriebenen [2.2]Phanen werden unter dem Gesichtspunkt der transanularen Wechselwirkung und der Molekuldeformation diskutiert. Transanular Interactions in [2.2]Phanes, III. [2.2](2,6)Naphthalinophane and [2.2](2,6)Naphthalinophane-1,11-diene Starting from the cyclic disulfide 7 the chiral [2.2](2,6)naphthalinophane 2 was synthesized by vapor phase pyrolysis of the disulfone 8. S-analogous Stevens rearrangement of the bissulfonium salt 10 (derived from 7) yielded 12 from which [2.2](2,6)naphthalinophane-1,11-diene 4 was obtained via13. There was no evidence for the formation of the corresponding achiral compounds 1 and 3. Catalytic hydrogenation converted 4 into 2. — 2 was resolved into enantiomers via diastereomeric charge transfer complexes with (−)-2-(2,4,5,7-tetranitro-9-fluorenylidenaminooxy)propionic acid. On the basis of sterical models for these complexes S-chirality is proposed for (−)-2. — The spectroscopic properties of 2,4, and the [2.2]phanes reported in the previous paper1) are discussed under the aspect of transanular interactions and molecular deformations.

Recent iron ore formation in Lake Malawi, Africa

Abstract: Nontronite, limonite (with opal) and vivianite are forming at present in the aereated, shallower parts (water depths <250 m) of Lake Malawi. They overlie diatomite or coarse grained clastic sediments. Our investigations indicate a precipitation of nontronite and limonite (and opal) at the sediment/oxic water interface from geothermal solutions rich in SiO2 percolating through the sedimentary fill of the basin. Under reducing conditions and a pH less than 7 (as occurring in the deeper parts of our sediment cores) iron and manganese are leached and discharged into the lake. In the anoxic parts of the lake (water depth greater than 250 m) Fe3+- and Mn3+-hydroxide are precipitated within the lake's water in the mixing zone of the aerobic with the anaerobic water bodies. High dispersion and a strong supply of detrital material, however, prevent a stronger enrichment of the hydroxides in the sediment. The formation of vivianite can be explained by a dissolution of Ca-phosphate (fish debris) within the sediment and a re-deposition as Fe-phosphate in the uppermost sediment layers under reducing but slightly alkaline conditions. The results of our investigations on Recent iron formation in Lake Malawi offer an explanation for the genesis of certain sedimentary iron ores in the geological past. They indicate that a formation of iron-rich sediments — including the silicate facies — is not restricted to the marine environment.

Biological activity and histocompatibility of dense Al2 O3/MgO ceramic implants in rats

Abstract: Three types of dense alumina oxide ceramic (Al2O3) 99.7%, MgO 0.3%; density more than 3.9 g/cm3 differing only in their average grain size (5–15μ) and stainless steel (V4A) plates were implanted into the left femur of male Wistar rats 6 months old. Light and scanning electron microscopic techniques were used to investigate tissue reaction and the ceramic surface. Both ceramic and stainless steel plates were surrounded by a soft tissue layer that differed greatly depending on the implant type in respect to the fiber/cell ratio. While the body tended to enclose the metal plate with a small more or less avascular tissue mostly composed of fibers and some inactive fibrocytes, around the ceramic implants a highly cellulated soft tissue of mesenchyme character developed with signs of osteoblast and chondrocyte metaplasia. Adjacent to this mesenchyme a dense cuff of newly formed woven bone arose, showing numerous active osteocytes. Both metaplastic tendency of the newly formed messenchyme and osteocyte activity in the surrounding bone did not decrease remarkably towards the end of the experiment (70 weeks after operation), while the tissue around metal implants reached a steady relatively reactive state 12–24 weeks after operation. Intimate ceramic surface-mesenchyme contacts without foreign body reactions supported the idea that alumina oxide ceramic tends to be incorporated into the body's physiological environment while metals are “excluded” by fibrous tissue layers of low biological activity. Corrosion on the ceramic surface was not detectable.

Compression Fractures of the Vertebrae during Major Epileptic Seizures

Abstract: SUMMARY The incidence of vertebral fractures caused by compression during grand mal seizures, the conditions that produce them, and their most common location were studied from the histories of 1, 487 patients and from radiological examination of 70 epileptic patients. Fractures caused by muscular contraction during grand mal attacks were located mainly in the dorsal column. They were found in about 15% of patients, more often in patients whose seizures started in adult life, and in those whose seizures occurred during sleep or who had suffered a grand mal status. RESUME A partir des donnees cliniques de 1, 487 patients epileptiques, dont 70 avec documentation radiologique, on a etudieľincidence, le sieage et les causes des fractures vertea-brales provoquees par compression pendant les crises grand mal. Les fractures provoquees par les contractions musculaires pendant les crises grand mal, etaient localisees surtout au niveau de la colonne dorsale. On les a trouve chez 15% des patients, le plus souvent de sex masculin qui preasentaient des crises ayant debuteaľâge adulte et des crises au cours du sommeil, ou apres les etats de mal epileptiques. ZUSAMMENFASSUNG Wirbelkorperkompressionsfrakturen bei Grand mal-Anfallen, ihr Zustandekommen und ihre haufigste Lokalisation wurden anhand von 1, 487 Krankengeschichten untersucht und in 70 Fallen rontgenologisch gesichert. Die durch Muskelkontraktionen hervorgerufenen Frakturen wahrend Grand mal-Anfallen waren hauptsachlich in der Brustwirbelsaule zu finden. Sie wurden bei etwa 15% der Patienten beobachtet, traten haufiger bei Mannern auf, sowie bei Patienten mit Grand mal-Beginn im Erwachsenenalter (besonders bei Schlaf-Grand mal) oder nach status epilepticus. RESUME El estudio se refiere a las fracturas vertebrales por compresion producidas durante ataques epilepticos de gran mal, las condiciones que las propician y su localization mas frecuente. Se basa en la revision de 1, 487 historias clinicas y en el estudio radio-logico intencionado de 70 epilepticos especialmente seleccionados. Se encontro que las fracturas vertebrales producidas por las contracciones muscu-lares de los ataques de gran mal se localizan principalmente en la columna dorsal; se presentan en aproximadamente el 15% de los pacientes con gran mal; son mas frecuentes en aquellos enfermos que inician sus crisis en la edad adulta, en los que sufren ataques durante el sueiio o en los que sufren un status de gran mal.

Differential blocking of myelinated nerve fibres by transient depolarization.

Abstract: 1. Conduction was blocked in the large myelinated fibres (Group II) of a cutaneous nerve by applying a transient polarizing current to the nerve. By appropriately adjusting the polarizing current conduction was not affected in most of the thin myelinated fibres (Group III) when all group II fibres were blocked. This selective action was achieved in 11 out of 15 experiments. Thus the method enables afferent volleys to be set up selectively in Group III fibres. 2. Recording single unit action potentials from the nerve revealed that the Group II compound volley is a reliable indicator for the extent of the block. As a prerequisite for this finding it was established by unit analysis that temporal dispersion due to the polarizing current did not occur within both Groups II and III fibre populations. 3. The membrane mechanism of the block was examined by testing the excitability changes in single fibres produced by the polarizing current. The findings indicate that the block was achieved by a membrane depolarization, causing inactivation of the sodium system. 4. Asynchronous firing produced by the blocking current itself, known to be a disturbing factor in such experiments, was shown to be virtually absent during the block. Discharges in Group II fibres evoked by the initial rise of the depolarizing current were prevented from conditioning the CNS effects of the selective Group III volley by appropriately advancing the onset of the current. 5. A complete and selective Group II block could also be performed during prolonged stimulation. In particular the method was shown to be able to ensure afferent activity being confined to small fibres during adequate stimulation of skin receptors.

Significance of the LP-X Test in Differential Diagnosis of Jaundice

Abstract: In recent years it has been well documented that the characteristic increase in plasma lipoproteins in patients with obstructive jaundice is the result of the presence of a low-density lipoprotein (relative density 1.006-1.063 g/ml) of abnormal composition and properties. This abnormal lipoprotein has been designated "LP-X." The development of a simple immunologic test system for determining LP-X provides the basis for a new clinical chemical test that is of use in the differential diagnosis of jaundice. In this study, 2680 LP-X determinations were performed on 1481 subjects: 1309 patients with or without liver disease, and 172 healthy volunteers. Statistical analysis of this series revealed a power of 0.99 and a specifity of 0.98 to demonstrate or exclude cholestasis. In this regard the new test is superior to other blood-chemical assessments. It was never positive in patients without liver disease. However, the LP-X test alone is not adequate to distinguish between intrahepatic cholestasis and extrahepatic biliary obstruction

Micropuncture studies after temporary ischemia of rat kidneys

Abstract: Micropuncture experiments were carried out on rat kidneys subjected to temporary ischemia (TI). Unilateral TI was performed by clamping the blood supply to the left kidney for 60 min. Time period between TI and investigating the kidney ranged from 1 h to 13 days. In another series of experiments blood supply to the left kidney was severely diminished for 24 h by a clip.-39% of animals developed anuria of the experimental kidney; in the other animals, urine flow rate was markedly decreased after TI (P<0.02). Employing the tracer microinjection technique considerable amounts (51%-oliguric kidneys; 17%-nonoliguric kidneys) of14C-labelled inulin injected into a proximal tubule of the damaged kidney were found in the urine of the contralateral kidney indicating backdiffusion of inulin through the damaged tubular epithelium. The amount of inulin recovered from both kidneys was decreased. Backdiffusion of inulin was detectable up to seven days after TI. Under control conditions 2% of inulin injected was found on the contralateral side, inulin recovered from both kidneys being approx. 100%. Dye intensity of Lissamine-green passing through the nephron was decreased noticeably after TI. Proximal tubular diameter and proximal free-flow pressure showed a large variability, the means being not significantly differnt from controls.—The results indicate that the concurrence of at least two factors are involved in the pathogenesis of acute renal damage induced by TI: Backdiffusion of tubular fluid through the damaged tubular epithelium and a decrease of glomerular filtration rate. The measurement of the clearance of inulin in kidneys damaged by ischemia does not represent the actual GFR, but underestimates this value proportionately to the degree of backdiffusion of inulin.

Mentally disordered violent offenders

Abstract: The essential result of our study is that crimes of violence committed by mentally ill and by mentally retarded are quantitatively proportional to the number of crimes of violence committed by the total population. In affective psychoses and mental retardation, the risk of committing an act of violence, which had to be calculated on the basis of inexact data, is about 6 in 100 000 approximately, and is one-tenth ofthat for schizophrenia (5 in 10 000). Factors which do not depend on the disorder, especially family and personality factors, seem to be relevant for the disposition to criminality. The disorder itself has different consequences. It generally seems to postpone the manifestation of the act of violence and thus raises the average age of the mentally-ill offenders. The closest connection between the crime motives and the disease can be assumed in depressed and schizophrenic offenders. The personality of the depressed seems to suppress the disposition to commit aggressive offenses with the exception of extended suicide as a combined act of violence and self-destruction. In schizophrenia, certain disturbances which can be found in chronic systematized paranoid syndromes seem to co-determine the motive of the offense, and are likely to favour its manifestation.

Specificity of IgA cold agglutinins: anti-Pr 1 .

Abstract: Monoclonal cold agglutinins have usually been found to be IgM(k) and to be directed against the I/i antigens. Three IgA(k) cold agglutinins were tested for antibody specificity. Based on the following criteria, they were shown to be directed against the Pr1 antigen of the Pr1/Pr2/Pra antigen system. The antigens reacting with the IgA(k) cold agglutinins were inactivated by protease and treatment of human red cells with neuraminidase and were demonstrable on human erythrocyte glycoproteins. The terminal sugar of the determinant group of these antigens is N-acetylneuraminic acid (NANA), which is not involved in I/i, but also in Pr2 antigenicity. The antigen activity of these antigens and the Pr2 and I antigen activities were distributed to different glycopeptide fractions obtained from red cell glycoproteins by ficin cleavage and Sephadex G-50 separation. Periodate oxidation of red cell glycoproteins, which causes a shortening of the polyhydroxy side chain at C-6 of C-9 NANA to a C-7 and/or C-8 NANA derivative, resulted in inactivation of these antigens, while the I antigen remained unchanged and the Pr2 antigen was increased 16–64-fold. Dog red cells gave no or diminished reactions with the three IgA(k) cold agglutinins, in contrast to increased reaction with anti-Pr2. Based on the different reactions of the IgA(k) cold agglutinins with dog red cells, a Pr1 heterogeneity Pr1h/Pr1d was demonstrated. In spite of the determination of the Pr1h/Pr1d/Pr2 and the MN antigens by NANA, both antigen systems were shown to be unrelated. Blocking of free e-lysine amino groups by acetylation or blocking of the NANA carboxyl groups by amidation of red cell glycoproteins resulted in MN inactivation, while the antigens reacting with the IgA(k) cold agglutinins (like Pr2) remained unaffected. The anti-Pr1 specificity of IgA cold agglutinins and the predominance of anti-I/-i specificity of IgM cold agglutinins was discussed with respect to inter-relations between immunoglobulin classes and antibody specificities of cold agglutinins.

Conversion of Angiotensin I into Angiotensin II in the Isolated Perfused Rat Kidney

Abstract: 1. In the isolated rat kidney, perfused at constant pressure with a medium free from renin substrate, addition of angiotensin I to the perfusate decreases renal ‘plasma’ flow. 2. A peptide inhibitor, SQ 20881, of converting enzyme reduces the vasoconstrictor effect of angiotensin I up to a maximum of 87%, the degree of inhibition being dose-dependent. 3. The molar, ratio of equi-effective doses of angiotensin I and angiotensin II was 50:1, indicating a low rate of intrarenal conversion of the decapeptide. 4. The vasoconstrictor effect elicited by the addition of renin substrate to the perfusate was not inhibited by SQ 20881, even if the concentration was fifteen times that which produced the maximum inhibition of conversion of angiotensin I.

Mikrotubulus-Anordnung und -Umordnung, Wandbildung und Zellmorphogenese in jungenSphagnum-Blättchen

Abstract: Sphagnum-Blattchen entwickeln sich durch sehr regelmasige aquale und (spater) inaquale Teilungen, die stets antiklinal sind. In sich nicht teilenden Zellen sind die Mikrotubuli (MT) mit dem Plasmalemma verbunden; sie laufen an den Innenwanden parallel (antiklinal), an den Ausenwanden in Streutextur. In der Praprophase sind sie in einem Praprophaseband konzentriert, wahrend der Mitose in der Spindel und im Phragmoplast und nach der Zellteilung in einer „Postcytokinese-Lage” an der jungen Wand. Ihre regelmasige Anordnung ermoglicht einige ungefahre quantitative Abschatzungen. Ihre Gesamtlange pro Zelle betragt etwa 500–900 μm in der Interphase, 1000 μm in der Praprophase, etwa 1000 μm (oder ein wenig mehr) in der Spindel und vermutlich auch im Phragmoplast und etwa 500 μm in der Postcytokinese. Zwischen einigen von diesen Stadien ist ihre Menge stark verringert. Die Gultigkeit und die Bedeutung dieser Befunde wird diskutiert. Die MT werden hauptsachlich durch Ab- und Wiederaufbau umgeordnet und wahrscheinlich nicht durch Verlagerung, obwohl sie sich moglicherweise manchmal auch in Langsrichtung bewegen. Ihre Verteilung an der jungen Wand, an den sich entwickelnden Spangen in den Hyalinzellen und an einigen sich besonders stark streckenden Wandzonen spricht dafur, das sie hauptsachlich als Cytoskelett-Elemente dienen, die an der Wandbildung und Zellmorphogenese beteiligt sind. Moglicherweise bilden sie lokale Wandverdickungen dadurch, das sie das Plasmalemma von der Wand — gegen den Turgor — abheben und einen extraplasmatischen Raum schaffen, in dem Wandmaterial (zuerst aus dem Golgi-Apparat) akkumuliert wird.

An approach to the theory of pressure broadening of spectral lines

Abstract: An attempt has been made to give a rigorous treatment of pressure or Stark broadening under the following assumptions: 1) the perturbating particles move independent of each other on straight lines with constant velocity v. The particles are distributed in the space with mean density n, the directions of their velocities are uniformly distributed on the unit sphere. 2) We neglect at all interactions of particles whose impact parameter is bigger than some constant ρ and we neglect interactions of particles with impact time tp at times t with |t − tp|⩾τ/2 where τ is another constant. Under these assumptions we get two formulae for the line profile I(ω) or its Fourier transform R(t)= = ∫ I(ω)eiωtd, Part II, Theorem 3 and 4. Both formulae are very similar in character. They consist of terms which are sums of one-particle-interactions, two-particle-interactions and so on. The first formula holds for any value of n, v, τ and ρ whereas the second one can only be proven for nπρ2 v τ < log 2. But the second formula is independent of τ and its one-particle approximation even of ρ. A detailed discussion of the second formula has been made in I. It clearly shows the nature of impact approximation.