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Biomedical subjects

C Meyer

Publications and source records attributed to C Meyer.

At least 469 records · Page 26Linked to original sources
PubMed1986

Haemodynamic effects of nifedipine in patients undergoing coronary artery bypass surgery.

Forty patients scheduled for elective aortocoronary bypass surgery were entered in a double-blind study set up to compare the haemodynamic effects of 20 mg nifedipine (n = 20) and placebo (n = 20), both administered with the premedication. Global left ventricular function was normal in all patients. Anaesthesia was induced and maintained with standardized doses of fentanyl, flunitrazepam, and pancuronium together with 50% N2O. Cardiovascular responses to anaesthesia, intubation, skin incision, sternal retraction, and aortic manipulation were investigated. Throughout the study nifedipine produced a marked decrease in systemic vascular resistance. The reduction of left ventricular afterload was associated with an increase in cardiac index. In contrast to other reports, we observed no severe hypotension after nifedipine administration. Mean arterial pressure in patients from the nifedipine group was lower than in the placebo group only prior to anaesthesia. Since no negative drug interactions between nifedipine and the anaesthetic agents were observed, we conclude that the established cardiovascular benefit of nifedipine should be continued during anaesthesia.

Adult↗
PubMed1986

[The red blood cells in growing guinea pigs. (Cavia cobaya). II. Communication: erythropoiesis and red blood cells in the postnatal development period].

Bone-marrow smears of 175 guinea pigs aged 1-27 days and venous blood samples of 351 animals aged 1-25 days were prepared for cell counting. A significant increase of erythroblasts were found between life day 1 and 2; normoblasts increased in number synchronously with a decrease of erythroblasts after the 5th day. The percentage of the erythroid bone marrow increased from 10 to 14 during the developmental period. Beyond the perinatal period the red blood picture is characterized by the following changes: a decrease of erythrocyte count, hematocrit, hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin; a constant mean corpuscular hemoglobin concentration; an increase of the reticulocyte count. The decrease of the red cell count is compensated by a decreasing oxygen affinity attained by an important increase of 2,3-DPG. Nevertheless, the stimulus for a raising erythropoiesis remains constant which can be shown by the growing percentage of erythroid cells and reticulocytes. The difference between the human postnatal development and that of the guinea pig becomes obvious. Cell counts in dependence of body masses in postnatally growing guinea pigs, veil the perinatal finding of the increase in erythrocytes up to the 5th day and the decrease of the mean corpuscular volume after the 3rd day.

Animals↗
PubMed1986

[The 4 second sleep spindle periodicity].

Polysomnographic EEGs were recorded from 12 adult volunteers between the ages of 20 and 50 years. They were given placebo, pentobarbital, carbromal, methaqualone, flunitrazepam, lormetazepam and triazolam. The visual evaluation was aimed at finding periodic sequences of centro-parietal sleep spindles at 13-15/s. Four consecutive spindles following each other regularly were defined as the shortest sequence. Placebo showed the following results: a considerable interindividual variance with 2 to 6 such sequences on the one hand and 25 on the other hand for each night. sequences with six periodically consecutive spindles dominated; the longest sequence contained 15 spindles. the inter-spindle distance was 4 seconds (m: 4.09; mean 4.14 s). All hypnotics caused an increase in periodic spindle sequences. Volunteers with a low tendency to have periodic spindle sequences remained at the lower end of the scale when taking hypnotics. Hypnotics increased the amount of longer spindle sequences, however, the average was still at sequences of 4-11 consecutive spindles. The inter-spindle distance became longer with all hypnotics; 4.34 s (carbromal) up to 4.58 s (flunitrazepam). Volunteers with a low tendency to have periodic spindle sequences showed shorter distances between spindles vice versa. Benzodiazepines do not reveal any characteristics due to their pharmacokinetic structure.

Adult↗
PubMed1986

Influence of various beverages on urine acid output.

High dose methotrexate therapy requires a high alkaline urine output. In order to evaluate the effect of various beverages on the urine acid output, healthy volunteers (n = 6) took 1.5-2 liters of a test drink during a 2-h period. On the test day urine pH and urine acid excretion (titratable acid plus ammonia minus bicarbonate) were measured. Controls received water and tea as test drink. Orange juice (pH 3.64) and tube feeding (pH 6.78) both led to alkaline urine pH and significantly decreased urine acid output compared to the control group (n = 4, P less than 0.01 and n = 3, P less than 0.001, respectively). Yoghurt (pH 4.1), buttermilk (pH 4.58), and Coca-Cola (pH 2.54), on the other hand, all induced a higher acid output than the control group (n = 6) and a urine pH less than 7.0 during the whole test day (n = 6, NS; n = 6, P less than 0.02; n = 4, P less than 0.05, respectively). If high urine output with an alkaline pH is required, fruit juices or well balanced tube feeding, both with low cation and low sulfur-bound amino acid content, can accomplish this. Drinks with high inorganic acid content (such as Coca-Cola) or high sulfur-bound amino acid content such as yoghurt and buttermilk will result in acidification of the urine.

Acids↗
PubMed1985

Effect of metoclopramide in diabetic gastroparesis.

The aims of our study were to: determine the effect of metoclopramide parenterally and orally on delayed gastric emptying of a radionuclide test meal in symptomatic patients with diabetic gastroparesis not explained by ulceration or other mechanical problems; and evaluate in a double-blind crossover fashion the efficacy of metoclopramide in relieving the symptoms of diabetic gastroparesis. Thirteen patients with subjective evidence of gastric stasis had delayed gastric emptying of an isotope-labeled semisolid meal which was significantly accelerated (p less than 0.05) after 10 mg of metoclopramide parenterally. Patients then received metoclopramide 10 mg and placebo before meals and prior to retiring for 3 weeks in a randomized double-blind crossover design. During metoclopramide therapy nausea, vomiting, anorexia, fullness, and bloating were significantly (p less than 0.05) ameliorated compared to placebo with an overall mean symptom reduction of 52.6%. Gastric emptying studies after completion of the trial is seven patients, subjectively improved and receiving open-labeled metoclopramide, showed significantly less gastric retention. Individual improvements in gastric emptying after parenteral or oral metoclopramide, however, could not be correlated with symptom change during the treatment trial. We conclude that metoclopramide is an important therapeutic adjunct in the management of diabetic gastroparesis and its therapeutic effects are mediated through its prokinetic properties as well as centrally mediated antiemetic actions.

Adult↗
PubMed1985

Chemotherapeutic agents and modulation of natural killer cell activity in vitro.

This study investigated the effect of various clinically used chemotherapeutic agents on non-modulated and human alpha Interferon (IFN) modulated natural killer cell (NK) activity. The inhibitors of DNA synthesis, Adriamycin, Cis-Platinum, 5-Fluorouracil and Methotrexate, did not alter NK cell activity at comparable clinically used doses. Similarly, Vincristine and Vinblastine, which are antimitotic agents, did not affect the NK activity. Only inhibitors of RNA synthesis L-Asparaginase and Actinomycin D reduced non-modulated and IFN modulated NK cell activity.

Antineoplastic Agents↗
PubMed1985

[Current status of the treatment of perforated duodenal ulcer].

A European study involving 15 major centres shows that the surgical treatment of a perforated duodenal ulcer depends closely upon the underlying condition and the operative risk. The latter is determined on the basis of the age of the subject, the time since the perforation, and the chronicity of the ulcer as well as the possible concomitant existence of severe medical pathology. In the optimal situation, preference is given to suture of the perforation and supraselective vagotomy. When general conditions are poor, the tendency is for a more simple approach such as simple suture or even the Taylor Wangensteen method. Type B II gastric resection remains indicated where there is associated bleeding or in the presence of large non-suturable ulcers which cannot be dealth with by a Rives-type patch of epiploon.

Age Factors↗
PubMed1985

[Early and late reaction of the guinea pig cochlea to impulse noise].

Guinea pigs (GP) were exposed to 10 impulses of 164 dB (SPL). Measuring of cochlear microphonics (CM) at frequencies between 0.5 and 10 kHz and morphological examination of the cochlea by the surface preparation technique followed 2 hours, 2 and 6 weeks after exposure to impulse noise. During the 2 hours following noise exposure the amplitudes of CM decreased in all tested frequencies, while recovery of CM never could be observed at this time. Subsequent morphological changes in the structure of the organ of Corti could be found. They varied considerably between the tested animals. 2 and 6 weeks after exposure to 10 impulses all GP had irreversible defects in the cochlea in an extent from an incomplete pattern of outer hair cells up to a total lack of areas of the organ of Corti. Only in GP with morphological damages in a small extent CM were recordable again. A good agreement of functional and morphological results was established. It can be concluded that exposure to few single impulses with peaks of sound pressure of sufficient intensity will produce irreversible morphological defects in the cochlea, resulting in marked functional injury, if the damaged area is large enough.

Animals↗
PubMed1985

[Total duodenal diversion by fundo-jejunostomy with Roux-Y-loop in the treatment of severe postoperative recurrent reflux esophagitis].

Fundo-jejunostomy with a 60 cm long Roux-en-Y loop removes almost all symptoms in severe postoperative recurrent reflux esophagitis. We analysed 12 own cases and compared them with those published in literature. 90% of most satisfactory results were obtained. Nevertheless indication for fundo-jejunostomy must be discussed and limited to those cases, which do not respond to medical treatment.

Duodenum↗
PubMed1985

[Thyroid metastases from a nephro-epithelioma].

The authors report a rare case of thyroid metastasis from a nephro-epithelioma, which appeared four years after nephrectomy, and was revealed by a Basedow-type goiter. It was treated by total thyroidectomy. A cervical recurrence was diagnosed in the course of a routine checkup and arteriography. Death occurred 22 years after thyroidectomy and 26 years after nephrectomy. The diagnosis is often only made at necropsy. The slow growth of these metastases does not preclude extended survival after surgical excision, and requires active therapy.

Adenocarcinoma↗