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Biomedical subjects

J Rohr

Publications and source records attributed to J Rohr.

At least 55 records · Page 3Linked to original sources
PubMed1987

Metabolic products of microorganisms. 240. Urdamycins, new angucycline antibiotics from Streptomyces fradiae. II. Structural studies of urdamycins B to F.

The structures of the angucycline antibiotics urdamycin B (5), E (2) and F (9) were established by comparing of their spectra with those of urdamycin A (1). The structures of urdamycins C and D, the largest compounds of this series, are still incomplete (10 and 11). The aglycones urdamycinone C, D and E can be liberated by methanolysis of the corresponding urdamycins. The liberation of urdamycinone B (6) requires an alcohol-free medium, to prevent its rearrangement to the naphthacenequinone 7 or 8. The urdamycins differ from other O-glycoside series in their variety of aglycones.

Aminoglycosides↗
PubMed1987

[Echocardiographic discoveries in 102 patients with vascular cerebral accidents].

The causes of vascular ischaemic accidents are numerous, and when the brain is involved management is limited to the prevention of similar events. Since cardiac sources of embolism potentially curable, we have prospectively analyzed the results of cardiovascular examinations (including ECG and radiography of the chest) and of echocardiography in 102 patients with cerebral or peripheral vascular ischaemic event in order to determine the impact of echocardiography and the influence of different diagnoses on the need for anticoagulant therapy. Intracardiac thrombi, mitral stenosis, dilated cardiomyopathy, severe left ventricular dysfunction with or without aneurysm and cardiac valve vegetations were regarded as diseases carrying a high risk of embolism, the low risk diseases being mitral valve prolapse, mitral annulus calcification and isolated left atrial dilatation. Atrial fibrillation was treated separately, as it may be associated with several of the diseases listed above. We found 14 diseases with a high risk of embolism (14 p. 100) and 35 diseases with a low risk of embolism (34 p. 100). 10/91 patients with cerebral vascular accident (11 p. 100) and 4/11 patients with peripheral vascular accident presented with a heart disease carrying a high risk of embolism. The most common heart disease with a high risk of embolism (10/14, 71 p. 100) was severe left ventricular dysfunction secondary to a coronary disease or a dilated cardiomyopathy. We did not find more cases of mitral valve prolapse or mitral annulus calcification than in the normal population. 20/29 patients with normal cardiac examination had a normal echocardiogram. The anticoagulant treatment was modified after echocardiography in only one case.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Successive spontaneous dissecting hematomas of both internal carotid arteries with a 3 1/2-year interval between them].

A case of spontaneous dissection of both internal carotid arteries is reported. There was an interval of 3 years and a half between the two dissections. The patient was a 33 year-old female, taking no contraceptives. Among possible favouring factors there was a kinking of both internal carotid arteries at the Cl level and the patient was submitted to cervical manipulations 2 weeks before the second dissection. The usefulness of Doppler ultrasonography to detect and follow the evolution of such lesions is emphasized.

Adult↗
PubMed1986

[Pulsatile tinnitus and arteriovenous fistulas of the dura mater].

A series of 12 patients with angiographically proven arteriovenous fistula of the dura mater are reported. This condition is more common than might be supposed and should be considered whenever a patient complains of pulsatile tinnitus accompanied by an auscultatory bruit. Doppler sonography is the noninvasive method of choice in arriving at a precise diagnosis and guiding neurological and radiological investigations towards selective angiography of the external carotid artery, the only technique which will reveal the origin of the pedicles. Doppler sonography is also very useful in monitoring the course of the untreated disease and its postoperative course. Although these fistulae may remain asymptomatic for a long time, depending upon their drainage and localization, they may give rise to serious complications, in particular haemorrhage, which render in general surgical treatment desirable. With regard to pathogenesis, the fistulae may be congenital, but are most frequently acquired.

Adult↗
PubMed1986

Motor neuropathy with proximal multifocal persistent conduction block, fasciculations and myokymia. Evolution to tetraplegia.

We describe a patient with chronic asymmetric motor neuropathy, which began in the upper extremity. The paretic muscles showed abundant fasciculations and myokymia but only little amyotrophy. Electrophysiologic examination revealed proximal multifocal persistent conduction block (CB) not located at the usual entrapment sites, and arrhythmic isolated or grouped fasciculation potentials originating distally on blocked axons. Over the years, new CBs developed, which led to tetraplegia, and amyotrophy slowly increased with progressive denervation. This patient differs from the cases of chronic acquired demyelinating polyneuropathy described in the literature by the absence of sensory deficit and the proximal location of CB.

Demyelinating Diseases↗
PubMed1986

Metabolic products of microorganisms. 234. Urdamycins, new angucycline antibiotics from Streptomyces fradiae. I. Isolation, characterization and biological properties.

The colored urdamycins A to F, six new angucycline antibiotics produced by Streptomyces fradiae strain Tü 2717, were detected by chemical screening. They are biologically active against Gram-positive bacteria and stem cells of murine L1210 leukemia. The urdamycins are glycosides and differ in their aglycones, which can be liberated by acidic hydrolysis besides the sugars D-olivose and L-rhodinose. The structure of the main compound, urdamycin A, follows from the spectroscopic and chemical data in connection with an X-ray analysis. The aglycone urdamycinone A is identical with aquayamycin. The structures of urdamycin B, E, F and partial structures of urdamycin C and D, will be presented in a subsequent paper. The new term "angucycline/angucyclinone" is used for an increasing group of related antibiotics.

Aminoglycosides↗
PubMed1986

[Ultrasonic studies and indications for angiography. Comparative study of 547 carotid arteries].

A correlation between continuous-wave Doppler sonography of 547 extracranial internal carotid arteries and angiography was established. Results were similar to those published until now: occlusions and high-grade stenoses (greater than 50%) were detected in more than 90% of the cases, whereas low-grade stenoses (less than 50%) and atheromatous plaques were detected only in 48% of the cases. In a few cases, it was difficult to distinguish total occlusion from subocclusion. As for small lesions, the results should be improved with the use of Doppler signal spectrum analysis. 87 internal carotid arteries were also examined with high resolution real-time B-mode imaging combined with pulsed Doppler (duplex system). With the exception of 10 bad quality examinations (11,4%), duplex was a very good method for the detection of every extracranial atheromatous pathology, above all for atheromatous plaques. The complementarity of conventional continuous-wave Doppler and duplex is emphasized. Whether it is possible to detect carotid artery ulcerations with real-time B-mode imaging is still a subject of controversy. Comparison between B-mode imaging and anatomopathology is discussed, with the hope that it will perhaps become possible to distinguish dangerous, embolising plaques. Ultrasound techniques are the best non-invasive ones to follow endarterectomised patients. Stenosis recurrency is probably more frequent than was thought before. Finally, the authors expose their own attitude as for the role of ultrasound in the investigation of cerebrovascular disease.

Adolescent↗
PubMed1985

Metabolic products of microorganisms. 225. Elloramycin, a new anthracycline-like antibiotic from Streptomyces olivaceus. Isolation, characterization, structure and biological properties.

Elloramycin (1), a new antibiotic produced by Streptomyces olivaceus strain Tü 2353, was detected by chemical screening. The dark yellow compound, molecular formula C32H36O15, is weakly active against a variety of Gram-positive bacteria, especially streptomycetes and against stem cells of L-1210 leukemia. Acidic hydrolysis of the antibiotic liberated elloramycinone (3) as aglycone and 2,3,4-tri-O-methyl-L-rhamnose, which was identified as methyl glycoside 5b. The structure of elloramycin was established by comparison of the spectra (UV, 1H NMR, 13C NMR) with those of the known tetracenomycin C (2), 3 and the fact that 2 and 3 gave the same tetramethyl ether after permethylation. Elloramycin is an anthracycline-like antibiotic, the aglycone resembles tetracenomycin C, the sugar is connected in a phenolic alpha-glycosidic linkage.

Animals↗
PubMed1985

[Spontaneous dissecting aneurysm of the internal carotid artery. General review of 205 published cases with 10 personal cases].

Spontaneous dissecting aneurysms of the internal carotid artery occur almost exclusively in the extracranial segment of the artery. The incidence is higher among males and the average age is relatively low (mean: 45 years). The existence of a lesion involving the wall of the carotid artery must be considered in the patient presenting with atypical facial neuralgia or incomplete but painful Horner's syndrome which may or may not be associated with a controlateral neurological deficit. Spontaneous dissecting aneurysms of the internal carotid artery cannot be diagnosed on the basis of a single angiogram. Definite diagnosis requires repeated ultrasonography and/or angiography. Spontaneous recanalization justifies the use of medical therapy (anticoagulant or antiplatelet aggregation therapy) in preference to surgical intervention.

Aortic Dissection↗
PubMed1985

[Spontaneous regression of a dura mater arteriovenous fistula of the posterior fossa].

A case of spontaneous regression of a posterior fossa dural arteriovenous malformation supplied by the left external carotid artery is reported. The patient, a 68-year-old woman, complained of pulsatile tinnitus most important at night. Two years after the malformation discovery, she presented a transient ischemic attack in the left middle cerebral artery territory. A new angiography showed that the malformation had disappeared; the left transverse sinus could not be opacified. The authors emphasise the interest of Doppler sonography for detection and follow-up of such malformations. They review the few published similar cases and discuss the different possible closure mechanisms of intracranial arteriovenous malformations.

Aged↗
PubMed1985

[Contribution of ultrasonic examinations to the detection of a posttraumatic vertebral arteriovenous fistula].

A case of extracranial vertebral arteriovenous fistula is reported. The patient was a 26 year-old female who had been submitted to a direct transcutaneous vertebral angiography 20 years before and had a noise in the neck discovered per chance during a clinical examination. Ultrasound usefulness to detect and to follow the evolution of such fistulas is emphasized. Clinical features and treatment are discussed.

Adult↗
PubMed1984

[Carotid stenosis: early detection].

Ultrasound techniques are currently the most reliable and precise methods for noninvasive detection of extracranial carotid artery disease. Continuous-wave-Doppler, associated with spectrum analysis, and high resolution realtime B-mode sonography are complementary. This is demonstrated by correlating ultrasound examinations and angiographies in 112 internal carotids. The value of B-mode sonography for the detection of atheromatous plaques is emphasized, this technique being superior even to angiography. The indications for ultrasound techniques are reviewed. They render possible prevention of cerebral vascular diseases due to extracranial carotid stenoses, and study of the natural history of atheromatous plaques.

Arterial Occlusive Diseases↗
PubMed1984

[Bilateral meningiomas of the optic nerves associated with partial unilateral Duane's syndrome].

A 34 years old man, with right eye blindness since childhood, presented with a decreased vision of the left eye 28 years later. Apart from bilateral papillary atrophy, right blindness and decreased left visual acuity, neuro-ophthalmological examination revealed a partial Duane's retraction syndrome on the right. Optic canal X-rays and cerebral CT-Scan revealed calcified meningiomas of both optic nerves. The diagnosis was confirmed at surgery. Cases of bilateral optic nerve meningioma are reviewed. The difficulties of diagnosis, the usefulness of the CT-Scan, the poor prognosis of the disease, even with surgery and radiotherapy are considered. No explanation was found for the association of the tumors with Duane's retraction syndrome.

Adult↗