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Biomedical subjects

P Strauss

Publications and source records attributed to P Strauss.

At least 37 records · Page 2Linked to original sources
PubMed1982

[Inner ear and diabetes mellitus experimental streptocotocin diabetes in rats].

The histological changes in the inner ear were compared with the hearing ability in insulin deficiency diabetes of rats. 38 LEW-Han-rats were treated with streptocotocin; 34 of these became diabetic, as proved by the glucose tolerance test. 22 rats served as controls. The diabetes was not treated. For a period of up to 440 days the weight, blood glucose and auditory function were controlled in the living animals. Auditory function was tested by means of pinnal reflex of Preyer for a frequency range between 1000 and 20000 cps. With regard to the mean values of frequency, neither a decrease nor a difference between normal controls and diabetic rats was found to any substantial degree. Histological examinations of sacrificed diabetic rats meanwhile showed the well-known changes in the kidneys with microaneurism, thickened basal lamina, mesangial proliferation, and hyaline bodies. The changes in the inner ear, especially in the region of the stria vascularis and lamina spiralis ossea to the ganglion cochleae, were rather discrete, so that no pronounced diminution of the auditory function as a result of restricted metabolism was to be expected. A loss of ganglion cells was seen in the spiral ganglion of the cochlea in correlation with ageing. There was no clear difference between diabetic rats and normal controls. Insulin deficiency diabetes causes severe changes in the vessels, as demonstrated in the kidney. In the inner ear, however, there were no comparable changes, the hearing ability of diabetic rats remaining practically normal.

Animals↗
PubMed1982

[Prinzmetal phenomenon and a rare coronary anomaly as infarct and death cause of a 45-year-old patient].

We report about the sudden death of a 45-year-old woman with anomalous origin of both coronary arteries from a single ostium in the right sinus of Valsalva, the left coronary artery running between the aorta and the pulmonary trunk. The clinical picture was that of Prinzmetal's form of variant angina, and it preceded death of inferior myocardial infarction. Coronary spasm and the anatomical anomaly were demonstrated by coronary angiography. There was no atheromatous plaque or other obstructive lesion in the dominant right coronary artery which could have explained the inferior myocardial infarction seen at autopsy. This is the first detailed report in which this rare coronary anomaly has been associated with Prinzmetal's variant angina. The demonstration of spasm in the dominant coronary artery and of an infarct in that part of the myocardium supplied by it in the absence of any anatomical obstruction suggests that this patient's death resulted from coronary spasm.

Angina Pectoris, Variant↗
PubMed1982

[Surgical treatment of middle ear cholesteatoma. Open versus closed technique (author's transl)].

The preservation of the posterior bony canal in cholesteatoma surgery produces a rate of new cholesteatoma formation which constitutes a risk for the patients. The rate of recurrent cholesteatoma could be diminished from 19% to 4% by the consistent reconstruction of the lateral attic wall by endogenous conchal cartilage, even if the defects are very small. The rate of residual cholesteatoma could be reduced from 29% to 3% by improvement of the surgical technique (= wide exposition of the attic) and by an adaptation of the rate of radicals to the results of each individual operator. Each individual operator has to increase the rate of radicals as far as the rate of residual cholesteatoma diminished to a level which can be accepted. A strict long-term follow-up is necessary if the bony canal is to be preserved in cholesteatoma surgery.

Cartilage↗
PubMed1982

[Inner ear and diabetes mellitus diabetic mutant mice].

We observed the course of diabetes in 23 genetically diabetic mice (C 57 BL/KSJ mdb) and in 25 controls (C 57 BL/KSJ). Diabetes was not treated. Histological changes of pancreas, aorta, kidneys, and inner ear vessels were noted. Auditory function was tested by means of the pinnal reflex of Preyer for a frequency range between 4000 and 20000 cps. The diabetic mice developed partly a mild diabetes associated with weight gain, and partly a severe diabetes with a loss of weight. Histologically, the diabetic mice showed (dependent on the duration and degree of severity of the diabetes) progressive mesangial sclerosis and thickening of basal laminas of the glomerula, as well as progressive slight to moderate thickening of the vascular walls of all inner ear vessels. The hearing ability of diabetic mice and of controls diminished with age to a comparable degree. The diabetic mice showed a slightly higher hearing loss for high frequencies, which did not correlate with the extent of thickening of inner ear vessel walls.

Animals↗
PubMed1982

[Inner ear and diabetes mellitus studies on 660 patients].

The purpose of this study was to examine the existence of any hearing loss typical of diabetes mellitus. 660 patients were interviewed by means of a questionnaire with regard to case history and the course of their disease. Internal and ophthalmological findings were registered which were compiled during clinical treatment for metabolic stabilisation. ENT examination was performed including vestibular and auditory tests. The evaluation of data showed that there was no median hearing loss which could be attributed to the diabetic metabolic disorder. The hypothesis that diabetes causes premature ageing with regard to hearing, could not be confirmed on a statistical basis. Statistical analysis of separate factors to establish links between diabetic disease, vascular risks, noise, or ear infections, does not yield any results.

Adult↗
PubMed1981

[The treatment of chronic adhesive otitis by tympanoplasty and active self-insufflation according to valsalva (author's transl)].

More than one year after tympanoplasty 85 to 95% of the followed up middle ears are aerated. The percentage depends on the degree of the preoperative adhesive process. We see the reason of this surprising success on the one hand in some special steps during operation (consequent silastic sheeting, preservation of the posterior bony canal with a deep middle ear cleft, visualisation of the tympanic orifice of the tube, widening of the natural connection between tympanon and mastoid without opening the chorda-facial-angle, some times mastoidectomy), on the other hand in a consequent postoperative follow up together with the surgeon until the ear is surely aerated controlled by self-insufflation (Valsalva). Therefore a preoperative tubal dysfunction is no contraindication for tympanoplasty: all ears should be operated. Because of the good results in hearing after just one operation, we try to rebuild the ossicular chain during the first intervention to avoid as often as possible a staged surgery.

Audiometry↗
PubMed1981

[Semimalignant" osteoma cutis].

A tumor is reported which originated rom an osteoma cutis and expanded into the surrounding tissue by infiltration and destruction. Histologically, there were no signs of malignancy. In cell culture there grew populations of bone-like tissue with highly active metabolism and negative contact inhibition. Therapeutic trials with diphosphonate are discussed.

Calcinosis↗
PubMed1980

The reticular formation differentiates heterotopic stimuli.

The role of the reticular formation (RF) in discriminative functions was studied in experiments on anaesthetized cats. In this association, a) the variability of responses in the RF (bipolarly recorded potential gradients - PG) to the same stimuli, and b) the responses of the RF to different (heterotopic) stimuli were recorded. The PG pattern in electrical stimulation of the same source (a nerve, skin) was constant during the time periods studied (several tens of minutes); even when the functional state of the RF was modified with strychnine, the basic characteristics of the responses usually remained intact. The pattern of PG generated by natural stimulation (tapping) was likewise reproduced with exactness at the level of statistical significance. Responses evoked from reciprocally remote receptor areas were manifestly different, at least in one of the depths investigated. The differences in stimulation of topically close areas were small. The results show that the RF, through its reactions, can differentiate heterotopic stimuli.

Animals↗
PubMed1980

[The influence of tympanoplasty on bone conduction (author's transl)].

Seldom tympanoplasty damages the inner ear in a substantial amount: From 1814 operations upon chronic inflamed ears 4 patients (0.22%) became deaf, among the other patients bone conduction (b.c.) in the mean increased at 1000 cps for + 0.8 dB and decreased at 4000 cps for - 2.2 dB. In 9.8% b.c. showed an improvement for 10 dB or more at 1000 and 4000 cps, 9.7% showed an corresponding deterioration. For patients it was confirmed on a statistical base, that the influence on bone conduction demonstrated by animal experiments (Tonndorf), was mainly the result of changing the compliance of oval window and of increasing ossicular inertia. By relieving a mobile stapes of an incus which was fixed in the attic, there results an improvement of mobility of the stapedial footplate with increasing b.c. at 1000 and 4000 cps. By interposition of an incus between tympanic membrane and stapes and by myringoplasty with fascia there results an increasing ossicular inertia with increasing b.c. at 1000 cps and decreasing b.c. at 4000 cps. Noise trauma, mechanical trauma and infection are only of slight importance, only in some single cases they will damage the inner ear in a substantial amount.

Bone Conduction↗
PubMed1980

[Formation of new bone and bone destruction in preserved incus homografts. Histological examinations of implants from 100 patients (author's transl)].

103 tympanoplastic re-operations were done in 100 patients. 103 Cialit-preserved incus homografts were drawn out for histological examination, which were implanted in the mean two years before. The data of the course of the disease were correlated with the histological finding. All incus homografts showed the well known formation of new bone in a different amount. Moreover 50% showed already macroscopically signs of bone resorption. Distinct indications for defense reactions of the recipient against the devital incus homograft were detected.

Bone Resorption↗
PubMed1980

[Experiments with autogenous tracheal replacement in rabbits (author's transl)].

Stenosis of the cervical trachea could be resected and replaced without tension, if a suitable prosthesis would be available. Postoperative stenosis of the anastomosis would be diminished by lowering the tension. In animal experiments with rabbits we succeeded in producing a tube, which was stabilised by autogenous cartilage and which has a smooth inner surface. This tube was similar to the rabbits trachea with regard to size and mechanical stability. Controlling the regeneration patterns of tracheal epithelium in rabbits there was demonstrated, that rather normal epithelium grew over scarred anastomosis by increased regeneration. The composition of an autogenous tracheal replacement tube could be the first step in reconstruction of parts of the cervical trachea.

Animals↗
PubMed1979

Synaptic responses of reticulospinal neurons in the cat: spinal cord dorsal funiculi are an effective source.

Stimulation of spinal cord dorsal funiculi (DF), as compared with stimulation of ventrolateral fascicle (VLF) in which the spinoreticular pathways are located, activated a higher percentage of reticulospinal (RS) neurons (95% vs. 75%). Polysynaptic EPSPs evoked from DF at C2 segment had shorter latency (10.1 msec +/- vs. VLF C2-13.2 msec +/- 0.9-mean +/- S.E.M.). When the intensity of stimulation was close to threshold (1.5 T), EPSPs from DF had steeper slopes on the increasing phase and were of longer duration. Threshold for setting up of synaptic activity from DF at the majority of observed RS neurons was low; recording of antidromic responses in hindlimb nerves showed that fast-conducting myelinized afferents were activated. The functional connection between DF and RS systems may participate in prompt and generalized reflex reactions.

Animals↗
PubMed1979

Caloric nystagmus: ENG in comparison with observation by Frenzel's glasses.

After caloric stimulation with water at 30 degrees C for 30 sec an electronystagmogram (ENG) was registered. Simultaneously with the ENG the test person's nystagmus was observed by Frenzel's glasses. If the evaluation is limited to the frequency of the nystagmus and if it is possible to neglect the velocity of the slow phase, the simple observation through Frenzel's glasses and its plotting on a time chart recorder is no less effective than an ENG for measuring the difference between the right and left labyrinth.

Adult↗
PubMed1979

Reticulospinal neurones with axons in the dorsal part of the lateral funiculus of the lumbar segments.

The presence of reticulospinal axons in the dorsal part of the lateral funiculus (DLF) of the lumbar spinal cord segments was tested in chloralose-anaesthetized cats. In the medial part of the reticular formation, 59 units which gave antidromic responses to stimulation of the isolated DLF of segment L1--L3 were observed. The rate of their axonal conduction was 20--120 m/s. 62% of the units generated discharge activity in response to electrical stimulation of the skin of the trunk and/or the limbs. The activating intraspinal pathways were localized in the DLF and the ventral part of the cord. The most effective natural stimulus was tapping. Monosynaptic control from cerebellar pathways was confirmed in 37% of reticulospinal neurones with axones in the DLF. The results showed that reticulospinal axones form part of the dorsal reticulospinal system in the lumbar cord region.

Action Potentials↗