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Biomedical subjects

P Muller

Publications and source records attributed to P Muller.

At least 73 records · Page 4Linked to original sources
PubMed1989

Analysis of hormone secretion by clinically nonfunctioning human pituitary adenomas using the reverse hemolytic plaque assay.

The reverse hemolytic plaque assay was used to study hormone release in vitro by seven clinically nonfunctioning human pituitary adenomas associated with no clinical or biochemical evidence of hormone excess. Four of seven tumors were oncocytomas, one a null cell adenoma, and two gonadotroph adenomas based on immunocytochemical and ultrastructural features. In all seven tumors, plaques were formed with antiserum against beta FSH; four produced plaques for beta LH, and five for glycoprotein hormone alpha-subunit. The percentage of plaque-forming cells and the mean size of plaques were smaller than those of clinically functioning adenomas studied for comparison (five GH- and/or PRL-producing adenomas). These results correlated with those of hormone release in tissue culture, immunocytochemistry on paraffin secretions of the tumors, and immunocytochemistry after reverse hemolytic plaque assay. We conclude that clinically nonfunctioning pituitary adenomas release small quantities of hormones, primarily gonadotropins, and that hormone release is attributable to only a small percentage of tumor cells.

Adenoma↗
PubMed1988

Gastrointestinal bleeding after craniotomy: a retrospective review of 518 patients.

A retrospective review of the medical records of 518 patients who underwent craniotomy over a 3 year interval was carried out to determine the rate of gastrointestinal bleeding and its relationship to the Glasgow Coma Score. There were 288 [55.5%] males and 230 [44.5%] females in the series; the mean age was 51.5 +/- 18.9 years. Forty percent had brain tumours, 18% had subarachnoid hemorrhage, 14% had spontaneous intracerebral hemorrhage, 19% had head injury and 8% had other diagnoses. Forty-eight [9.3%] of the patients had significant gastrointestinal bleeding, the distribution of which was as follows: hematemesis [37/518], melena [11/518] and/or hematochezia [4/518]. A further 51 [9.8%] had evidence of "coffee ground emesis" only. Of those with a Glasgow Coma Score of less than 10, 21% had significant GI bleeding while only 7% of patients with a Glasgow Coma Score greater than 10 had such a bleed [p less than 0.005]. Further analysis showed that the incidence of GI bleeding in patients who underwent craniotomy increased with decreasing GCS. GI bleeding did not correlate with age, sex, steroid administration or casual use of anti-ulcer medication.

Adult↗
PubMed1988

A study of ligamentous growth.

Scant data are available on the growth of ligament. This study answers basic questions concerning mechanisms of ligament growth and determines the location of longitudinal ligament growth. Growing rabbits had metal marking sutures implanted, at measured intervals, along the length of their medial collateral ligament. Separate metal markers were inserted in the epiphysis and metaphysis of the femur and tibia. Changes in marker intervals were measured radiographically after growth. Measurements revealed that growth occurred throughout the length of the ligament, with somewhat greater growth occurring in the distal segment. Total ligament growth was much less than that occurring at the tibial physis (which the ligament crosses). The magnitude of total ligament growth was proportional to the enlargement of the joint itself, as measured by changes in the distance between epiphyseal markers. The most distal suture inserted in the ligament became incorporated in bone and moved rapidly away from the ligament insertion. This rapid displacement of the distal suture was not responsible for enlargement of the ligament itself, but rather a phenomenon of the maintenance of the position of the ligament insertion on the proximal metaphysis, as the epiphysis grows away from the original site of ligament insertion.

Animals↗
PubMed1987

Flow cytometric analysis and sorting of plant chromosomes from Petunia hybrida protoplasts.

A method to obtain a high metaphase index and thereafter a plant chromosome suspension is described for Petunia hybrida (2n = 14). Mesophyll protoplast cultures have been used, giving easily disrupted cell walls and a high percentage of dividing cells after 42 h. On 2.5 mM colchicine-treated cells, metaphase indexes reaching 10% were routinely obtained. The lysis medium in which the protoplast-derived cells were disrupted was a simplified culture medium. After chromosome release, samples were stained with Hoechst 33342 dye and analysed by flow cytofluorometry. The histogram of fluorescence intensities included three peaks of metaphase chromosomes and a duplication of this flow karyotype provoked by "monochromatid chromosome." This interpretation was established after flow sorting; micronuclei could also be observed and sorted. Of the 7 chromosomes, only the largest formed a distinct peak while the others were incompletely resolved, due to the similar DNA content of various chromosomes. Model distributions of Petunia hybrida chromosomes have been computed according to the relative chromosome length. The theoretical histograms indicated that low variability is indispensable for resolving distinctive chromosome peaks. The experimental flow karyotype was consistent with one of the models having CV of 2.5%.

Benzimidazoles↗
PubMed1987

Immediate effects of bumetanide on systemic haemodynamics and left ventricular volume in acute and chronic heart failure.

1 The haemodynamic and radionuclide effects of i.v. bumetanide (25 micrograms kg-1) were prospectively studied in 24 patients with angiographically documented coronary artery disease and either acute exercise-induced (Group I, n = 12) or chronic (Group II, n = 12) heart failure. 2 Bumetanide at rest increased systemic arterial blood pressure and vascular resistance index; cardiac index and pulmonary artery occluded pressure (PAOP) were reduced at an unchanged heart rate in all patients. The left ventricular ejection fraction fell in patients with normal resting left ventricular filling pressure without change in those with chronic heart failure. The cardiac volumes were unchanged in either group. 3 During constant-load supine bicycle exercise, there were similar effects on systemic arterial pressures, vascular resistance index and PAOP; however the cardiac index was maintained at a reduced left ventricular filling pressure and unchanged ejection fraction and volumes. 4 These data demonstrate immediate mild pressor and vasoconstrictor actions of bumetanide which appear independent of the state of cardiac function; they suggest that any immediate improvement in patient symptomatology following bumetanide may be consequent on the reduction in PAOP; short-term reductions in volume may not occur.

Acute Disease↗
PubMed1987

Famotidine: proven once-a-day treatment for gastric ulcer.

An 8-week, double-blind, randomized, placebo-controlled, multinational (n = 14), multicenter (n = 44) trial was conducted to determine whether famotidine speeds healing and relief of symptoms in patients with benign gastric ulcer. Of the 336 patients who entered the trial, 167 received 40 mg of famotidine in the evening, and 169 received placebo. At 4, 6, and 8 weeks after entry, ulcers had healed in a significantly (P less than 0.01) higher percentage of famotidine-treated patients than in those treated with placebo (47%, 65%, 80% versus 31%, 46%, 54%, respectively). Famotidine was also superior to placebo in relieving ulcer symptoms; the proportion of patients receiving additional antacid therapy was significantly lower in the famotidine group. The findings show that the new H2-receptor antagonist famotidine, administered as a single evening dose, significantly speeds the healing of benign gastric ulcers and that it is a safe and highly effective treatment of gastric ulceration. The convenient dosage regimen of famotidine (one tablet in the evening) should improve patient compliance, which, in turn, may result in faster healing of ulcers and a lower incidence of ulcer complications.

Adult↗
PubMed1987

[Alveolar microlithiasis. A study of minerals in the lung].

A pulmonary scintigraph of pyrophosphate was performed to assess calcium metabolism in a man of 39 with alveolar microlithiasis, as was histologic study with a mineral analysis of wave-length dispersion and an analysis crossing the microliths enclosed in the resin. Two treatments were tried without success: First with diphosphonates and then alveolar lavage.

Adult↗
PubMed1987

[Sleep apnea syndrome combined with an anatomical obstruction of the upper airways].

In patients with sleep apnoea syndrome abnormalities of the upper airways may play a major role in the genesis of apnoea. Three cases are presented which illustrate the part played by hypertrophy of the tonsils in a child and by stenosis of the pharynx in an adult and of the larynx in another adult. All three patients were cured by surgical correction of these abnormalities. The physiopathology of alveolar hypoventilation, present in one of the three patients, is discussed in relation to the effects of pure oxygen inhalation on the patient's ventilation.

Adult↗
PubMed1986

[Incidence of polyneuropathies in chronic obstructive bronchopneumopathies].

In a prospective study 43 patients with chronic obstructive lung disease and severe respiratory insufficiency were systematically investigated for polyneuropathy, although they had no risk factor of that disease. Electrophysiological recordings showed slight or significant signs of polyneuropathy in 17 and 15 patients respectively, thus indicating that the condition is frequent. Clinically, it was often silent or manifested only by sensory disorders predominant in the lower limbs. Electrophysiology suggested axonal degeneration associated with some degree of demyelinization, and these lesions were found at histology to be present in sensory nerves. Histological examination of the muscles showed peripheral mixed neurogenic atrophy probably due to hypoxia. Major thickening of basal material was observed in capillaries of the endomysium and endoneurium. Statistical analysis of clinical parameters and respiratory function values in relation to the presence and importance of polyneuropathy showed that the only significant difference was the longer duration of hypoxia in patients with nerve involvement. Age, alcoholism and the other respiratory function values did not seem to be correlated with lesions of the peripheral nervous system.

Aged↗
PubMed1986

[Neuropathies and chronic respiratory insufficiency: electrophysiologic study].

In order to determine the frequency and the characteristics of neuropathies in chronic respiratory insufficiency, a systematic study of 43 patients affected by a chronic obstructive pulmonary disease was performed. In addition to neurological and electrophysiological examinations (including 6 nerve conduction studies on median, ulnar and peroneal nerves and EMG of 4 to 8 muscles), nerve and muscle biopsies (of the superficial peroneal nerve and lateral peroneus brevis muscle) were performed in 13 cases. Polyneuropathies were found in 74% patients: but mild in 39%, severe in 35%. Most were subclinical or poorly symptomatic. We determined the importance and distribution of abnormalities on the different nerves. From this we established that neuropathies are mixed but predominantly of the axonal type. Axonal degeneration and demyelination were confirmed by nerve biopsy; muscles presented neurogenic atrophy. Statistical analysis showed that the duration of hypoxemia was related to neuropathy. The pathogeny of these neuropathies is discussed.

Adult↗
PubMed1985

Comparative effects of cytochalasin D on the protein discharge induced by alpha- and beta-adrenergic or cholinergic agonists in rat exorbital lacrimal glands.

Cytochalasin D altered the kinetics of peroxidase and radiolabeled protein discharge from rat exorbital lacrimal glands in vitro, in response to various secretagogues. The changes were different with each inducer. The discharge due to isoproterenol was immediately inhibited by 95%; the discharge evoked by noradrenaline via alpha-adrenergic receptors was progressively reduced and was inhibited by 50% after 30 min, whereas that evoked by carbachol was not influenced during the initial discharge period and was diminished by only 30% after 30 min. When calcium was removed from the incubation medium, the secretory responses were lowered and the inhibitory effect of cytochalasin D was still observed. The rate of protein discharge inhibition was related to the dose and was maximal with 2 X 10(-6) M cytochalasin D when the discharge resulted from cholinergic, alpha- or beta-adrenergic or dibutyryl cAMP stimulation. Cytochalasin D did not impair cellular energetics nor other stimulations induced through muscarinic or adrenergic receptors. Cytochalasin D effects could be related to interaction with actin, leading to the inhibition of the release of proteins into the incubation medium following the activation of the adrenergic system.

Adrenergic alpha-Agonists↗
PubMed1985

Haemodynamic dose-response effects of intravenous nisoldipine in coronary artery disease.

The circulatory consequences of slow-calcium channel blockade with a new dihydropyridine nisoldipine were evaluated at rest and during exercise-induced angina in 16 patients with angiographically proven coronary artery disease. In 10 patients resting cardiac stroke output (thermodilution) and pulmonary artery occluded pressure were determined following four intravenous nisoldipine injections (cumulative dosage of 1, 2, 4 and 8 micrograms kg-1). The exercise effects of nisoldipine were evaluated by comparing the effects of the 8 micrograms kg-1 cumulative dosage with a control exercise period at the same workload. At rest nisoldipine reduced systemic vascular resistance and mean arterial pressure, and increased heart rate, cardiac and stroke volume indices. During 4 min supine-bicycle exercise nisoldipine reduced systemic mean arterial pressure and vascular resistance; this resulted in augmented cardiac and stroke volume indices at an unchanged pulmonary artery occluded pressure. In six additional patients rest and exercise ejection fractions were measured using a nonimaging nuclear probe. Nisoldipine (4 micrograms kg-1) resulted in a small trend to increase left ventricular rest and exercise ejection fraction. These data demonstrated improved rest and exercise cardiac performance following nisoldipine in patients with severe coronary artery disease.

Adult↗
PubMed1985

[A case of diverticular gastric heterotopy of the small intestine].

Report of an observation of a small intestine diverticulum with colic and gastric heterotopy in a seven year old girl. Unrecognized for many years, the lesion was at the origin of a severe digestive hemorrhage for which an urgent operation was necessary. A propos of this new enough case (30 published cases), characteristics of diverticular gastric heterotopy are remembered from diagnostic, nosologic and therapeutic point of view. Their individualization with regard to Meckel's diverticulum and remainders of omphalo-mesenteric canal is emphasized.

Child↗
PubMed1984

ADP-ribosyltransferase from beef liver which ADP-ribosylates elongation factor-2.

Fragment A of diphtheria toxin and Pseudomonas toxin A intoxicate cells by ADP-ribosylating the diphthamide residue of elongation factor-2 (EF-2) resulting in an inhibition of protein synthesis [1-3]. A cellular enzyme from polyoma virus transformed baby hamster kidney (pyBHK) cells ADP-ribosylates EF-2 in an identical manner [4]. Here we describe a similar cellular enzyme from beef liver which transfers [adenosine-14C]ADP-ribose from NAD to EF-2. The 14C-label can be removed from the EF-2 by snake venom phosphodiesterase as a soluble product which comigrates with AMP on TLC plates, indicating the 14C-label is present on EF-2 as monomeric units of ADP-ribose. Furthermore, the forward transferase reaction catalyzed by the beef liver ADP-ribosyltransferase is reversible by excess diphtheria toxin fragment A, with the formation of 14C-labeled NAD, indicating that both transferases ADP-ribosylate the same site on the diphthamide residue of EF-2. Thus, beef liver and pyBHK mono(ADP-ribosyl)transferases both modify the diphthamide residue of EF-2, in a manner identical to diphtheria toxin fragment A and Pseudomonas toxin A. These results suggest the cellular enzyme is probably ubiquitous among eukaryotic cells.

ADP Ribose Transferases↗