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M Doll

Publications and source records attributed to M Doll.

6 recordsLinked to original sources
PubMed2000

Acute triiodothyronine administration does not reverse depressed contractile performance following catecholamine exposure in isolated rat cardiomyocytes.

BACKGROUND: It has been previously suggested that triiodothyronine (T3) may reverse depressed cardiac contractile performance occurring after excessive catecholamine stimulation. We therefore investigated the effects of T3 on intracellular calcium transients and contractile performance in isolated ventricular rat myocytes. METHODS: Isolated rat myocytes were loaded with the calcium indicator FURA-2/AM (50 micromol/L) and superfused with Krebs-Henseleit solution (pH 7.4). Cells were illuminated by ultraviolet light and fluorescent images obtained with a target camera at 340 nm and 380 nm excitation wavelengths (ratio method). Simultaneous measurements of calcium transients and cell shortening (35 degrees C, electrical field stimulation: 0.5 Hz) were done. At steady state conditions, FURA-2 loaded myocytes were superfused for 60 min with epinephrine (0.1 micromol/L). After 60 min the effect of T3 (10 micromol/L) on calcium transients and shortening were measured. As control, only the effect of 10 micromol/L T3 was analyzed. RESULTS: Epinephrine significantly increased cell shortening and FURA-2 signals to 148.6+/-8.8% and 109.5+/-3.1% (p < 0.01: n = 21; 5 min) respectively. With longer epinephrine exposure, the increase in cell shortening continuously declined to 134.6+/-7.9% with no change in FURA-2 fluorescence. Acute administration of T3 after epinephrine exposure lowered contractile performance from 136.2 +/- 15.5% to 102 +/- 8.2 %, after 10 minutes. In control experiments acute administration of T3 increased basal contractile response from 100% to 115.8+/-3.3% (p<0.01; n = 8; 5 min). CONCLUSIONS: This study confirms previous reports of impaired cardiac function after high catecholamine exposure. High catecholamine exposure is associated with a desensitization of contractile proteins for calcium. Acute T3 administration increased contractility in untreated myocytes, but further depressed myocyte shortening in epinephrine-treated cells. Our results show that T3 is ineffective at restoring myocardial contractility after excessive catecholamine stimulation.

Animals↗
PubMed1989

Retained intraspinal bullet--an illustrative case report.

In a 35 year old male who had suffered a gunshot injury one bullet remained in the spine at level C 5. Clinically, a complete high tetraplegia was found. Already during the first months after trauma the patient complained of dysaesthesia and hyperaesthesia in the segments at, and above, the lesion. Five years later, when the authors saw the patient, he reported on an increase of intensity of this pain since some months. This gave occasion to radiological investigations to rule out morphological changes as the origin of the increase in pain. CT showed a compact bullet exactly intraspinal, with a syringiform cyst projecting into the myelon. Since former CT scans did not exist, an objective statement on progress could not be given. However, it is suspected that chronic inflammation caused by metal breakdown products of the bullet may have contributed to the increasing pain. It is pointed out that it is necessary to take account the kind of metal when deciding for or against the removal of a foreign body.

Adult↗
PubMed1987

[Computed tomography of atelectasis. A comparative experimental study].

After breathing pure oxygen, total atelectasis of one lung was produced in ten dogs; its development and regression was followed by CT and by conventional radiology. 30 seconds after cessation of ventilation, it was possible to show a rise in CT density of the atelectatic lung from -764 +/- 32 HU to -739 +/- 49 HU. The average time from the cessation of ventilation to total atelectasis averaged 5.5 +/- 1.1 minutes. The earliest sign on conventional radiographs was often seen after 30 seconds and usually after 60 seconds and consisted of mediastinal displacement. Extensive atelectasis regressed in only one out of six animals within one hour after resuming ventilation. The experimental methods and results and the significance of the physiological findings in a clinical context are discussed.

Animals↗
PubMed1986

[Clinical significance of sonographically detected splenomegaly].

In 502 patients, length, thickness and width of the spleen as well its location with respect to the ipsilateral kidney were determined by means of ultrasonography, and a relationship was established with the incidence of diseases accompanied by enlargement of the spleen. A significant correlation to the incidence of such diseases was found only with respect to spleen thickness. The probability of a corresponding disease was 80% for a spleen thickness of 5 cm, 90% for 6 cm and 100% for more than 7 cm. A comparison between palpation and ultrasonography supported the fact that enlargement of the spleen can, in many cases, not be ascertained by palpation, but that palpation findings are indeed positive in splenic enlargement of minor degree. The most suitable parameter for ultrasonographic detection of splenomegaly is thus spleen thickness, for which a limit value of 5 cm should be assumed. If the spleen is found to exceed this value, further examinations are indicated to clarify the underlying disease.

Humans↗