Susceptibility and amplification of sensitivity in contact dermatitis.

We have examined the hypothesis that people who develop contact allergies to environmental substances do so because they have heightened susceptibility. Analysis of data from 2200 consecutive patients tested with the 20 commonest antigens in a patch-test clinic showed that more people developed multiple contact allergies than would be predicted from the frequency of single allergies; the excess was too great to be explained by chance and increased with number and rarity of the combinations of sensitizers. The possibility that this was due to enhanced individual susceptibility to sensitization rather than concomitant exposure to several sensitizers was confirmed by showing that patients with multiple allergies are more readily sensitized experimentally, and to a greater degree than normal, by dinitrochlorobenzene (DNCB), an unrelated antigen. The defect involves induction rather than expression of sensitivity. Amplification of the response to DNCB is proportional to susceptibility (calculated from the ratio of observed prevalence of multiple allergies to that predicted from the prevalence of single allergies) throughout the range from normal subjects, through those with a single sensitivity, to those with rare, multiple allergies. Therefore, we conclude that individual susceptibility is an important factor in the development of contact dermatitis, and occurs by a non-antigen-specific amplification of immune sensitization.     

The fine structure of chordoma with particular reference to the physaliphorous cell

A chordoma was examined by electron microscopy. It was composed of stellate and physaliphorous cells. The fine structure of these cells is described. Transitional type cells are also described and it is suggested that the physaliphorous cells develop from the stellate cells through a process of vacuolation. Two types of vacuoles are described, `smooth-walled' and `villous' endowed with numerous structureless microvilli. Some observations on stained sections are discussed.     

Isolation and characterization of human and rabbit sperm tail fibrous sheath

Using mechanical and chemical dissection methods, fibrous sheath was isolated both from normal ejaculated human spermatozoa and from rabbit cauda epididymal spermatozoa. The same techniques did not produce a pure preparation of fibrous sheath from ejaculated rabbit spermatozoa, suggesting that further cross-linking and stabilization of sperm structures occurs in response to components of the seminal plasma. The isolation procedures were monitored by phase contrast microscopy and the purity of the fibrous sheath was verified by electron microscopy. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of isolated human fibrous sheath revealed at least 14 protein bands of which the most intensely stained were of molecular weight 84, 72, 66.2, 57, 32 and 28.5 kDa. The rabbit fibrous sheath revealed at least 10 protein bands, of which the most intensely stained were 35.2, 32.7 and 28.5 kDa. The amino acid composition of the purified fibrous sheath from human and rabbit spermatozoa was similar, being high in aspartic acid and/or asparagine and glutamic acid and/or glutamine, serine, alanine, leucine, lysine and glycine, but low in histidine, tyrosine and isoleucine. This composition is similar to that reported for the rat and suggests that mammalian sperm tail fibrous sheaths are composed of similar types of proteins, although there are apparent differences in protein components between species.      

Acute and Subacute Toxicity of Aspilia Africana Leaves

This study was designed to evaluate the toxicity of the aqueous extract of Aspilia africana leaves. Oral doses of 500 mg/kg and 1000 mg/kg were administered for 28 days to rats after every 2 days for sub-acute toxicity. For acute toxicity, 5 doses of 2, 4, 8, 12 and 16g/Kg body weight were investigated in mice. The control groups consisted of mice or rats administered with distilled water. The signs of toxicity fluctuated lightly from one mammal to another throughout the experiment. The liver, kidneys and heart weight of rats revealed no significant differences between the test groups and the control. The results indicated that the medium lethal dose (LD₅₀) was found to be greater in females than males with an average of 6.6g/Kg body weight for both sexes. Regardless of the significant differences observed at certain points in some biochemical parameters (ALT, AST, ALP, Creatinine and Glutathione); none showed any linear dose responsiveness. On the other hand, most of the parameters investigated were found to be gender dependent. These results suggested that A Africana can be classified among substances with low toxicity.     

Restriction of visual experience to a single orientation affects the organization of orientation columns in cat visual cortex

Summary and Conclusions In six dark reared, 4-weak-old kittens visual experience was restricted to contours of a single orientation, horizontal or vertical, using cylindrical lenses. Subsequently, the deoxyglucose method was used to determine whether these artificial raising conditions had affected the development of orientation columns in the visual cortex. After application of the deoxyglucose pulse one hemifield was stimulated with vertical, the other with horizontal contours. Thus, from interhemispheric comparison, changes in columnar systems corresponding to experienced and inexperienced orientations could be determined. The following results were obtained: (1) Irrespective of the restrictions in visual experience, orientation columns develop in areas 17, 18, 19 and in the visual areas of the posterior suprasylvian sulcus. (2) Within area 17, spacing between columns encoding the same orientations is remarkably regular (1 mm), is not influenced by selective experience and shows only slight interindividual variation. (3) In non-striate areas the spacing of columns is less regular and the spatial frequency of the periodicity is lower. (4) The modifiability of this columnar pattern by selective experience is small within the granular layer of striate cortex but substantial in non-granular layers: Within layer IV columns whose preference corresponds to the experienced orientation are wider and more active than those encoding the orthogonal orientation but the columnar grid remains basically unaltered. Outside layer IV the columnar system is maintained only for columns encoding the experienced orientations. The deprived columns by contrast frequently fail to extend into non-granular layers and remain confined to the vicinity of layer IV. (5) These modifications in the columnar arrangement are more pronounced in striate cortex than in non-striate visual areas and, within the former, more conspicuous in the central than in the peripheral representation of the visual field. It is concluded that within layer IV the blue print for the system of orientation columns is determined by genetic instructions: first order cells in layer IV develop orientation selectivity irrespective of experience whereby the preference for a particular orientation is predetermined by the position in the columnar grid. Dependent on experience is, however, the expansion of the columnar system from layer IV into non-granular layers. It is argued that all distortions following selective rearing can be accounted for by competitive interactions between intracortical pathways, the mechanisms being identical to those established for competitive processes in the domain of ocular dominance columns. It is proposed that such experience dependent modifiability of connections between first and second order cells is a necessary prerequisite for the development of orientation selectivity in cells with large and complex receptive fields.This work has partially been supported by a grant from the Deutsche Forschungsgemeinschaft, SFB 50, A14Dedicated to Prof. D. Ploog on the occasion of his 60th anniversaryResearch Fellow of the Alexander-von Humboldt-Stiftung     

Renovaskuläre Hypertonie

Zusammenfassung In der vorliegenden Untersuchung wurde das postoperative Blutdruckverhalten bei 35 Patienten mit renovaskulärer Hypertonie untersucht: 17 Patienten mit fibromuskulärer Dysplasie (FMD) und 18 mit arteriosklerotischen Gefäßwandveränderungen (ASS).Patienten mit FMD waren im Mittel jünger (31,8 Jahre), zeigten eine kürzere Hypertonieanamnese (1,8 Jahre) und waren prävalent weiblich (82%), während Patienten mit ASS deutlich älter waren (48,2 Jahre), eine längere Hypertoniedauer (2,6 Jahre) zeigten und bevorzugt männlich (78%) waren.In beiden Gruppen zeigte das intravenöse Pyelogramm einen vergleichbar hohen Anteil positiver Befunde (FMD=64%, ASS=61%).Postoperativ waren in der Gruppe mit FMD 47% (n=8) geheilt, 47% (n=8) gebessert und nur 6% (n=1) der Patienten geringgradig gebessert. Die vergleichbaren Werte für die Gruppe mit ASS betrugen 28, 55 und 17%. Für das Gesamtkollektiv war folglich ein guter Operationserfolg (geheilt und gebessert) in 88,5% der Fälle zu beobachten. Patienten mit ASS und postoperativ nur geringgradiger Besserung (n=3) zeigten eine auffallend lange Hypertonieanamnese (7,0±1,4 Jahre).Bei allen Patienten wurde präoperativ die seitengetrennte Bestimmung der Renin-Aktivität (PRA) im Nierenvenenblut durchgeführt und aus den Werten die PRA-Quotienten (PRA betroffene/nicht betroffene Seite) errechnet. Bei 27 Patienten wurde die Bestimmung 15 und 30 min nach intravenöser Stimulation mit 40 mg Furosemid wiederholt. PRA-Quotienten von 1,5 wurden als signifikant bezeichnet.Bei 31 Patienten mit einseitiger renovaskulärer Hypertonie wurde die Höhe des PRA-Quotienten zum postoperativen Blutdruckverhalten korreliert. Dabei zeigte sich zwischen der Gruppe der postoperativ Geheilten und der der postoperativ Gebesserten kein signifikanter Unterschied im mittleren PRA-Quotienten. Ferner ließen sich für das Gesamtkollektiv der 31 Patienten mit einseitiger renovaskulärer Hypertonie unter Ausgangs- und Stimulationsbedingungen keine signifikanten Korrelationen zwischen Höhe der PRA-Quotienten und postoperativem Blutdruckabfall ermitteln.Unsere Ergebnisse unterstützen nicht die weit verbreitete Ansicht, daß sich die seitengetrennte Bestimmung der PRA im Nierenvenenblut als Parameter für den zu erwartenden Operationserfolg bei Patienten mit einseitiger renovaskulärer Hypertonie eignet. Die Methode kann deshalb nach unserer Ansicht nicht mehr als obligater Bestandteile der präoperativen Diagnostik der renovaskulären Hypertonie empfohlen werden.     

Experimental determination of the kinetics of calcium-binding with chondroitin sulphate and the effects of uric acid on this process

Summary The calcium-binding kinetics of chondroitin sulphate C (CS) have been determined using equilibrium analysis including ⁴⁵Ca. There is a linear relationship between the extent of the Ca binding and the concentration of CS present. 1 mol CS disaccharide unit binds 0.757 mol Ca. Scatchard plots of the data have revealed a single constant of dissociation (K _D =1429). In the presence of urate ions, and dependent on the pH value, the ability of CS to bind Ca may be impaired by as much as 31%. These measurements have supported the theory that urate ions interact with the GAGs in urine.     

Cardiovascular parameters and scoring systems in the evaluation of response to therapy in sepsis and septic shock

Summary In 47 medical and postoperative ICU patients with 57 episodes of sepsis and septic shock, cardiovascular parameters including systemic vascular resistance (SVR), cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI) as well as six scoring systems (APACHE II, Elebute, Goris, HIS, SAPS and SSS) were studied regarding their usefulness in the assessment of disease progression and evaluation of response to supplemental sepsis therapy (immunoglobulins, plasmapheresis). Among the hemodynamic parameters, only a prompt SVR improvement significantly discriminated between ultimate survivors and nonsurvivors. Thus, an increase in SVR (>160 dyn*cm^–5*sec, within days 0 to 4, persisting for >24 hours) can serve as a prognostically validated response criterion (responders/non-responders: 26/31; mortality: 27% vs. 77%). Non-invasively, the APACHE II score was best suited (specificity: 88%, sensitivity: 67%) to classify hemodynamically defined responders to supplemental sepsis treatment (score-reduction 4 on day 4 after onset of therapy).

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Herz-Kreislauf-Parameter und Score-Systeme in der Beurteilung des Therapieerfolges bei Sepsis und septischem Schock

Zusammenfassung Bei 47 internistischen sowie postoperativen Intensivpatienten mit insgesamt 57 Episoden von Sepsis und septischem Schock wurden Herz-Kreislauf-Parameter inklusive systemischer Gefäßwiderstand (SGW), Herzindex, Schlagvolumenindex und linksventrikulärer Schlagarbeitsindex sowie sechs Score-Systeme (APACHE II, Elebute, Goris, HIS, SAPS und SSS) in ihrer Wertigkeit zur Beurteilung des Krankheitsverlaufes sowie des Ansprechens auf additive Sepsistherapie (Immunglobuline, Plasmapherese) untersucht. Von den hämodynamischen Parametern diskriminierte nur der — prompt nachweisbare — Anstieg des SGW signifikant zwischen letztlich überlebenden und nicht überlebenden Patienten. Ein Anstieg des SGW (>160 dyn*c^m–5*s innerhalb von vier Tagen, länger als 24 Stunden anhaltend) kann somit als prognostisch validiertes Responder-Kriterium dienen (Responder/Non-Responder: 26/31; Letalität: 27% vs. 77%). Nichtinvasiv erwies sich der APACHE II Score (Kriterium: Score-Abfall 4 bis zum Tag 4 nach Therapiebeginn) zur Klassifizierung der hämodynamisch definierten Therapie-Responder bei additiver Sepsistherapie am besten geeignet (Spezifität: 88%, Sensitivität 67%).