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D Binder

Publications and source records attributed to D Binder.

53 records · Page 3Linked to original sources

Neurons at the origin of the medial component of the bulbopontine spinoreticular tract in the rat: an anatomical study using horseradish peroxidase retrograde transport.

An anatomical technique based on the retrograde transport of horseradish peroxidase (HRP) was used to investigate the projections of spinal cord neurons to the reticular formations in the rat. Both large and restricted injections were staggered all along the bulbar and pontine levels, involving the nucleus gigantocellularis, the nuclei reticularis pontis, pars oralis and caudalis and in some cases the nucleus raphé magnus. Labeled cells were constantly encountered in the reticular part of the neck of the dorsal horn throughout the whole length of the cord, mainly contralateral to the central core of the injection site. This area was taken as the equivalent of lamina V in the cat. Other labeled cells were observed in the medial parts of the intermediate and ventral horns, in areas considered similar to laminae VII and VIII in the cat. The two most rostral cervical segments were characterized by an additional bilateral projection originating from the dorsolateral part of ventral horns. Thus, this study is a clear confirmation that the bulbopontine reticular formations constitute a target for various somatosensory inputs originating in spinal cord. It demonstrates that the medial spinoreticular tract (mSRT) differs from the other main ascending tracts by the absence of projections from (1) superficial layers and nucleus of the dorsolateral funiculus contrary to the spinomesencephalic tract; (2) ventromedial zone of the lumbar dorsal horn unlike the spinothalamic tract; (3) the neck of the dorsal horn in its medial portion contrary to the spinoreticular component reaching the lateral reticular nucleus; and (4) central cervical nucleus and Clarke's columns, unlike the spinocerebellar tracts. The difficulty in demonstrating retrograde labeling from discrete injections could result from the fact that mSRT neurons have sparsely ramified collaterals on their terminal zones.

Afferent Pathways↗

[Heterocyclics fused to pyrazine-1,4-dioxide. 3. Synthesis and antibacterial effect of substituted pteridine--5,8-dioxides].

The synthesis of substituted pteridine-5,8-dioxides (6) via reaction of furoxanes (5) with enolizing carbonyl compounds is described. Compounds 5 are obtained either through reaction of chloro pyrimidines 1 with sodium azide, or through diazotization of hydrazino pyrimidine 2 and subsequent thermal decomposition of 3 or through nucleophilic displacement of methoxy against amino groups in 5. The antibacterial activity of the compounds 6a and 6c is directed against some gramnegative organisms, i.e. E. coli, Klebsiella spp. and Proteus spp., with MIC values and ED50 values which do not exceed those of the corresponding pyridol [2,3-b]pyrazine-1,4-dioxides.

Animals↗

The origin of the spinomesencephalic tract in the rat: an anatomical study using the retrograde transport of horseradish peroxidase.

An anatomical technique based on the retrograde transport of horseradish peroxidase (HRP) was used to investigate the projections of spinal cord neurons to the mesencephalic tegmentum in the rat. Restricted unilateral injections were confined to central grey, cuneiformis areas, and superior colliculus. Injections into all these loci produced labeling in similar spinal areas. Only quantitative differences were noted. In the spinal grey matter, numerous labeled cells were regularly encountered in the marginal zone, the lateral part of the neck of the dorsal horn, and the dorsal grey commissure. Projections from the marginal zone and neck of the dorsal horn were predominantly contralateral. In the white matter, a pronounced bilateral labeling was observed in the nucleus of the dorsolateral funiculus, thus confirming our previous electrophysiological findings (Menétrey et al., '80). This distribution of labeled cells was commonly observed throughout the whole length of the cord. Additional sites of projecting cells have also been identified at the most rostral levels (obex, C1, C2). They mostly derived from spinal extensions of the dorsal column nuclei and lateral cervical nucleus contralaterally; from the lateral ventral horns bilaterally and from the nucleus commissuralis ipsilaterally. This study is thus a clear confirmation that the mesencephalic tegmentum constitutes a target for various somatosensory inputs originating from spinal cord, dorsal column nuclei, and lateral cervical nucleus. Moreover, from these results together with those obtained for the spinothalamic tract in the rat, it appears that marginal and dorsolateral funiculus neurons preferentially project to the mesencephalic tegmentum. The importance of marginal zone projections underlines the involvement of the spinomesencephalic tract in pain mechanisms.

Afferent Pathways↗

[Pyrazine-1,4-dioxides fused to heterocycles / 2nd comm.: Synthesis and antibacterial activity of substituted pyrido[2,3-b]pyrazine-1,4-dioxides (author's transl)].

The position selective synthesis of substituted pyrido[2,3-b]-pyrazine-1,4-dioxides is reported. Compound 3g was subjected to a series of screening-tests for antibacterial activity and compared to therapeutical standards. The range of antibacterial activity mainly comprises enterobacteriaceae, above all E. coli, Klebsiella, Proteus and Shigella strains. Activity against gram-positive organisms and Serratia is much weaker and completely lacking with Pseudomonas. Therapeutic activity in septicaemic infections of the mouse is very good, especially in the case of E. coli infection with an ED50 of 13 mg/kg mouse for s.c. application. With p.o. application 3g shows activity comparable to nalidixic acid and nitrofurantoin in the experimental acute pyelonephritis in the mouse. The activity of 3g, however, is clearly inferior to that of gentamicin.

Animals↗

Responses of neurons of the nucleus raphe magnus to noxious stimuli.

Extra-cellular recordings were made from neurons located in nuclei raphé magnus (nRM) and reticularis paragigantocellularis (nRPGC) of intact rats. Noxious cutaneous and visceral stimuli elicited either excitatory or inhibitory effects, unaffected by innocuous stimuli while most of the noxious-inhibited neurons gave brief excitatory responses to innocuous brisk taps. It is suggested that the organization of these areas and their involvement in analgesic effects is much more complex than previously described.

Animals↗

Neurones responding to noxious stimulation in VB complex and caudal adjacent regions in the thalamus of the rat.

(1) 163 cells responding to mechanical cutaneous stimulation have been recorded in VB complex and caudal adjacent region in rats anaesthetized with a mixture of 2/3 N2O--1/3 O2 and 0.5% halothane. (2) 51 cells were exclusively activated by non-noxious cutaneous stimuli applied to restricted and contralateral receptive fields (RF) and had the classical characteristics of "lemniscal" responses. 93 cells responded only to noxious mechanical stimuli (N cells) and had either uni- or bilateral receptive fields. 19 cells responded both to noxious and non-noxious stimuli (NnN cells). (3) When tested with intense electrical stimuli applied transcutaneously or on the sural nerve, N and NnN cells responded with a late irregular discharge. Poststimulus histograms obtained in one-third of these units revealed that the late component was consistent with a C fibre input; some of responses were consistent with A delta fibre input. NnN cells also had a short latency discharge probably due to A alpha fibre involvement. (4) When tested with other intense stimuli such as noxious radiant heat or noxious visceral stimulation induced by intraperitoneal injection of bradykinin, N and NnN cells were strongly activated. (5) The different kinds of cells were scattered in VB and PO and no significant differences were found between cells recorded in VB and caudal adjacent region (PO); however, a rostrocaudal organization of the cells, according to the location of their RF on the caudal or rostral part of the body, was clear not only for the Nn cells but also for N and NnN cells.

Animals↗

Synthesis and biological activity of 15-arylprostaglandins.

Prostaglandin analogues in which the alkyl chain attached to C-15 in the natural compounds is replaced by an aryl group have been synthesised. Some of these compounds are potent luteolytic agents and comparisons are drawn between this series and 16-aryloxyprostaglandins.

Animals↗

[Subungual melanoma with linear nail pigmentation].

A 53 year old male patient presented with a dark-brown linear pigmentation of the thumb nail due to a subungual melanoma mainly of the superficial spreading melanoma-type. Melanin-induced nail pigmentations are recommended to be treated by a resection in local anaemia of the dorsal two thirds of the terminal phalanx. This procedure combines sufficient radical surgery with a good functional and acceptable cosmetic result.

Fingers↗

Native and prosthetic valve endocarditis caused by Rothia dentocariosa: diagnostic and therapeutic considerations.

Three cases, one each of native valve, prosthetic valve and composite graft endocarditis caused by Rothia dentocariosa are described. The first patient presented with multiple brain abscesses and severe congestive heart failure due to destructive endocarditis with large vegetations on the mitral valve. He died shortly after emergency valve replacement. Gram-positive coccoid rods were identified in the vegetations of the excised mitral valve. The second patient had a R. dentocariosa endocarditis of a prosthetic aortic valve that was treated empirically with netilmicin and teicoplanin, due to an allergy to penicillin. Both antibiotics were replaced according to susceptibility testing in vitro with rifampin and ciprofloxacin, and the endocarditis was cured within 9 weeks. The third patient presented with a circular root abscess of an aortic composite graft that was successfully treated with rifampin and ceftriaxone without surgery. All patients had extensive periodontal disease which was thought to be responsible for hematogenic spread and seeding of the microorganism. The microbiological identification and antibiotic resistance pattern of the isolates, as well as therapeutic implications are discussed.

Actinomycetales↗

Effects of pH on the dentin surface.

A microleakage and scanning electron microscope (SEM) study was conducted in order to investigate the effects of acidic primers on prepared dentin surfaces. The microleakage study revealed that no significant differences were noted between the five materials tested in regard to leakage at enamel and dentin margins. SEM analyses revealed that the smear layers of all specimens were altered in some manner. Further long-term clinical studies should be conducted to evaluate acidic treatment of dentin.

Composite Resins↗