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Biomedical subjects

M Hahn

Publications and source records attributed to M Hahn.

At least 271 records · Page 15Linked to original sources
PubMed1979

[Ensuring ureter viability: experimental study].

1. In experiments on dogs we observed that the remaining of the peripelvic and periureteral tissue in taking from the kidney is not decisive for the blood supply of the ureter. That these findings are important also for the clinic is confirmed by the following fact: in order to draw the ureter through the natireflux tunnel, 2-4 cm of the periureteral tissue must be removed. However, we never observed a necrosis restricted to this place. 2. In all experiments the blood supply of the upper half of the donor ureters was confirmed without any mistake. Therefore we recommend to shorten the ureter to this length for the UNC. 3. The preservation by means of hypothermy or permanent machine perfusion has no negative effect on the blood supply of the ureter.

Animals↗
PubMed1978

Pneumatic otoscopy and impedance studies in middle ear diagnosis.

The direct inspection of the tympanic membrane and its movement with Siegle pneumatic otoscopy through the binocular microscope and the electroacoustic measurements of impedance at the tympanic membrane give valuable information in the diagnosis of tympanic membrane and middle ear disorders. Problems such as otosclerosis and tympanosclerosis with ossicular chain fixation, ossicular discontinuities, ossicular chain prosthesis defects and perilymph fistulas, and the problems of middle ear fluid can be identified and differentiated. Frequently a precise diagnosis can be determined prior to surgical exploration. The use of these instruments enables the otologist to anticipate surgical findings and plan a specific procedure, thereby avoiding operative surprises. The routine use of the pneumatic otoscope and an electroacoustic impedance bridge is recommended in every case of suspected tympanic membrane or middle ear disorder, particularly where an operation is being considered. The combined information obtained through use of the two diagnostic techniques is almost always greater than that obtained by either instrument alone. Pressure recordings were made in a series of examinations with the pneumatic otoscope using the ear microscope. These pressures, both positive and negative, are acceptable and well within the range utilized by clinical electroacoustic impedance bridges. Contraindications to the use of pneumatic otoscopy and the electroacoustic impedance bridge are discussed.

Acoustic Impedance Tests↗
PubMed1978

Chronic treatment with LH-RH in golden hamsters.

Male golden hamsters were treated with low doses (50 or 100 ng) or high doses (500-1000 ng) of LH-RH for periods of 10 to 21 days. Gonadal atrophy was induced by blinding. Treatment of intact hamsters with high doses of LH-RH reduced pituitary sensitivity to a test dose of LH-RH given at the end of the experiment. Concomitantly, testis and seminal vesicles were reduced in weight. In blind hamsters with gonadal atrophy, low dose treatment with LH-RH for 21 days reversed testicular atrophy and restored spermatogenesis, while the high dose treatment partly reversed testicular atrophy (viz. increased tubular diameter) but inhibited spermatogenesis. Low dose treatment also increased testicular and seminal vesicles weight in blinded hamsters, whereas high dose treatment did not change these parameters. It is concluded, that a positive effect on testicular functiion may only be obtained by low dose treatment with LH-RH, whereas high dose treatment induces a negative feedback blocking the effect of LH-RH on pituitary gonadotrophin secretion.

Animals↗
PubMed1978

Optimal perfusion parameters in kidney preservation.

The optimal pressure in the renal artery during initial perfusion with Collins' solution by spontaneous pressure in canine kidneys is 40-50 cm H2O and in human kidneys 40-60 cm H2O. An average-sized human kidney can be perfused by a full current which is limited only by the lumen of the infusion set. In smaller than average-sized human kidneys the current must be reduced to diminish the pressure in the renal artery to the optimal value. In prolonged hypothermal perfusion by means of a Gambro apparatus it will be necessary to assess the optimal pressure by direct measurement in the renal artery in intact average-sized human kidneys because the pressure reading on the manometer is not identical with the optimal pressure in the renal artery.

Animals↗