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.

[Value of systematic toxicological analysis in the management of drug addicts]

This study was carried out between March and December 1985, on 50 drug addicts, including 45 heroin users, hospitalized for detoxication. We compared the clinical informations obtained at the time of admission with the toxicological informations obtained from blood and urinary samples. If the drugs said to have been used over the last 48 hours are always found, in 52% of these cases some other drugs are found too. The reasons of this difference between clinical and toxicological informations are analysed as well as their consequences on diagnosis and treatment. This data finally shows the importance of systematic toxicological analysis in the treatment of drug addicts as well as in the epidemiological studies.

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.

[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.

[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.

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.

[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.

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.

The 2-deoxyglucose uptake method as a first screen for neurotoxic compounds

Our primary goal is to develop a screening procedure to detect and partially characterize neurotoxic compounds. There is a great need for a new approach to screening for neurotoxicants because our industrialized world abounds with untested and potentially neurotoxic compounds. A large number of new compounds are introduced each year. Although a number of testing approaches to the screening for neurotoxicants have been proposed in the recent years, a consensus on the most adequate approach is yet to emerge. The existing methods share a number of shortcomings. Thus, most methods only detect a fraction of the tested neurotoxicants. Other methods lack the necessary resolution to detect the neurotoxic damage reproducibly and reliably. Furthermore, many screening approaches are too time consuming and costly to be used for the large-scale screening of neurotoxicants. It is, therefore, imperative to develop reliable and efficient screening methods applicable in regulatory toxicology. In this report, we describe two versions of the same method that we feel may be very beneficial for the large-scale screening of neurotoxicants. The 2-deoxyglucose (2-DG) uptake method provides an indirect measure of neuronal activity in different areas of the brain. The ability of the method to detect most, if not all, neuroactive substances is reviewed in this report. In the context of this report, a neuroactive substance is defined as a substance acting directly on the central or peripheral nervous system neurons and (or) glia. The 2-DG method equals the sensitivity of the most sensitive alternative methods which were selectively designed to detect the effects of specific groups of compounds. The generality and sensitivity of the 2-DG method are of major importance. Thus, if a tested compound does not affect the uptake of 2-DG into the brain, it is not likely to be neuroactive. Since neurotoxic compounds are a subset of neuroactive compounds, a compound that is not neuroactive is also not neurotoxic. Thus, a single test may, in some instances, determine if a tested compound is nontoxic. In addition, it appears that each compound or, at least, each family of compounds produces a characteristic profile ("pattern") of the sites of altered 2-DG uptake. This pattern can be exploited to characterize the tested compound and help us decide whether it is neurotoxic or neuroactive. Preliminary results from our laboratory indicate classical neurotoxic agents such as acrylamide, triethyltin, and 2,5-hexanedione induce a generalized depression of the 2-DG uptake throughout the brain.(ABSTRACT TRUNCATED AT 400 WORDS)

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.

[Pregnancy and delivery in adolescents. Apropos of 112 case reports]

The authors studied the course of pregnancy in 112 adolescents under the age of 15 years 3 months seen over the last decade. 10% of pregnancies were marked by anaemia, 23% by excessive weight gain and 20% by toxaemia of pregnancy. Although the delivery is often premature, it is usually simple, with rapid labour and expulsion. Forceps were required in 8% of cases and the ventouse was used in 11% of cases. Epidural anaesthesia was performed in 50% of deliveries. Despite an almost normal pregnancy and a eutocic delivery, 21% of babies presented a malformation.

Microtubules and protein secretion in rat lacrimal glands: localization of short-term effects of colchicine on the secretory process

The pathway and kinetics of the secretory protein transport in rat lacrimal exorbital gland have been established by an in vitro time-course radioautographic study of pulse-labeled protein secretion. The colchicine-sensitive steps have been localized by using the drug at various times with respect to the pulse labeling of proteins. Colchicine (10 microM) does not block any step of the secretory protein transport, but when introduced before the pulse it decreases the transfer of labeled proteins from the rough endoplasmic reticulum to the Golgi area, suppressing their temporary accumulation in the Golgi area before any alteration of this organelle is detectable. Moreover, colchicine inhibits protein release only from the secretory granules formed in its presence because the peroxidase discharge is diminished 1 h after colchicine addition, and the secretion of newly synthesized proteins is strongly inhibited only when colchicine is introduced before secretory granule formation. Morphometric studies show that there is a great increase of secondary lysosomes, related to crinophagy, as early as 40-50 min after colchicine is added. However, changes in lysosomal enzymatic activities remained biochemically undetectable. We conclude that: (a) the labile microtubular system does not seem indispensable for protein transport in the rough endoplasmic reticulum-Golgi area but may facilitate this step, perhaps by maintaining the spatial organization of this area; and (b) in the lacrimal gland, colchicine inhibits protein release not by acting on the steps of secretion following the secretory granule formation, but by acting chiefly on the steps preceding secretory granule formation, perhaps by making the secretory granules formed in its presence incapable of discharging their content.

Molecular defects in inborn disorders of collagen metabolism

Disturbances of collagen metabolism may result in the manifestation of clinical symptoms. The collagen disorders that best characterized are genetically inherited and are known to vary at the clinical and molecular levels. Defective posttranslational modifications of collagen chains due to mutant enzymes have been found in patients with the Ehlers-Danlos syndrome and cutis laxa. Altered selection of collagen types and defective primary structure of the molecules themselves are prominent features in osteogenesis imperfecta. In other pathological conditions, such as Marfan syndrome, no clear molecular defect has been identified as yet.

Massive cerebral edema associated with fulminant hepatic failure in acetaminophen overdose: possible role of cranial decompression

Cerebral edema may complicate the course of fulminant hepatic failure. Response to conventional therapy has been disappointing. We present a patient with fatal acetaminophen-induced fulminant hepatic failure, with signs and symptoms of cerebral edema, unresponsive to conventional medical therapy. Cranial decompression was carried out. A justification of the need for further evaluation of cranial decompression in such patients is presented.

[Practical thoughts on the matter of responsibility in phlebology]

If the general concept of responsibility has been widening, so, too, the concept of medical responsibility. The changes in outlook may be good for us in that they oblige us personally to keep a check on our medical actions. But they also gradually restrict our medical rights, and our right to make ethical decisions. The most notable points in these changes include the concept of enlightened consent, important considerations of the comparative pros and cons of all treatment or diagnosis; considerations too of the time spent on these, and examinations of our work-methods, and of the means used in our practice. One of the most notable changes concerns the patient-doctor relationship. Taken to extremes, such changes could have a negative and paralysing effect on medical practice, and be detrimental to the patient.

The effects of long-term ethanol on brain receptors for dopamine, acetylcholine, serotonin and noradrenaline

Rats were treated with ethanol for 11-15 days, after which the brain neurotransmitter receptors for dopamine, acetylcholine, serotonin and noradrenaline were measured. The rats were intubated at 12 h intervals with 4 g/kg ethanol, and sacrificed 10 h after the last intubation. After ethanol treatment, the specific binding of 3H-haloperidol to dopamine receptors was significantly decreased in the mesolimbic areas by 20 +/- 6%, but was unchanged in the striatum. Specific binding of 3H-serotonin was increased by 63 +/- 29% in the striatum and by 32 +/- 9% in the brainstem, but decreased by 20 +/- 7% in the hippocampus. The specific binding of 3H-quinuclidinyl benzilate to muscarinic acetylcholine receptors increased by 7 +/- 2% in the striatum, but decreased by 5 +/- 2% in the cerebral cortex. The specific binding of 3H-WB-4101 to alpha-adrenergic receptors was unchanged in all brain areas assayed, namely the striatum, mesolimbic areas, hippocampus, hypothalamus, brainstem and cerebral cortex. These changes may be related to some aspects of tolerance to, and dependence on, ethanol.