[Recurrent retroperitoneal giant lipoma (author's transl)]

A giant lipoma weighing 9.1 kg situated retroperitoneally which was removed by operation from a 74-year-old woman is reported. The diagnosis of tumors is discussed. The characteristics of this primary benign tumor such as the rapid growth, tendency to malignant degeneration and recurrence make radical surgical removal necessary.

beta-blocking agents and human fat cell adenylate cyclase

The effects of various beta-blocking agents upon the catecholamine-activated adenylate cyclase of human fat cell ghosts were studied. Both non-selective and cardio-selective beta-blocking drugs are capable in inhibiting the human enzyme system. The concentrations of the non-selective beta-blockers (bupranolol, alprenolol, propranolol, 4-hydroxypropranolol, prindolol and oxyprenolol) required to produce half maximal inhibition of isoproterenol-stimulated rates of cAMP-formation were found to be in a narrow range (5X10(-7) M-3X10(-6) M).The cardioselective beta-blocking agents, however, were only 1/100 (methypranol) to 1/1000 (atenolol, practolol) as potent as the non-selective drugs.

[Poisoning after ingestion of mussels (mytilus edulis) (author's transl)]

Symptoms of poisoning occurred in 19 persons in the Rhein-Main region in October 1976, after they had eaten mussels (Mytilus edulis) imported from Vigo, Spain. Mild oral paraesthesias, tingling in the fingertips and feet were followed by generalised numbness and dizziness. All symptoms disappeared within 48 hours. They had been caused by saxitoxin which is produced by a dinoflagellate and accumulated in the mussels, as confirmed by testing confiscated samples of mussels. Toxin concentration ranged from 6000 to 20 000 MU (mice units) per 100 g mussel meat.

Histamine-sensitive adenylate cyclase of human gastric mucosa

The adenylate cyclase system of human fundic gastric mucosa was found to respond to histamine, prostaglandin E 2 and the non-hormonal activators NaF and 5'-guanylyl-imidodiphosphate (GMP(PNP)). Half maximal stimulation of enzyme activity was observed at a histamine concentration of 50 micrometer. Maximal stimulation (about 25%) occurred at a histamine concentration of 1 mM. The stimulatory effect of histamine was competitively inhibited by cimetidine. The stimulatory effect of prostaglandin E 2 was found to be dose-dependent over a concentration range from 0.1 micrometer to 1 mM exerting maximal effects at 0.3 mM. NaF and GMP(PNP) by inducing an about 3.5-fold increase of enzyme activity were more potent in stimulating the human enzyme system than histamine and prostaglandin E 2. Maximal stimulatory doses of prostaglandin E 2 and histamine had an additive effect on the adenylate cyclase activity from fundic gastric mucosa. This implies that histamine acts on an individual adenylate cyclase system. Our results are suggestive for the existence of an adenylate cyclase system in human gastric mucosa coupled to histamine H 2-receptor sites.

Catecholamine-sensitive adenylate cyclase of human fat cell ghosts. Inhibition of isoproterenol-stimulation by dihydroergotamine

Isoproterenol-activation of the adenylate cyclase system of human fat cell ghosts was markedly inhibited by dihydroergotamine which had no effect on basal and NaF-stimulated enzyme activity. Our results indicate that the antilipolytic action of this substance in human adipose tissue is probably due to inhibition of catecholamine-sensitive adenylate cyclase activity.

beta-adrenergic receptor coupled-adenylate cyclase of human fat cell ghosts

The effects of beta-adrenergic agonists such as isoproterenol, norepinephrine and epinephrine upon the adenylate cyclase activity of human fat cell ghosts were tested, each alone and in combination with the beta-blocking agent propranolol. Saturating concentrations of these agents showed a 2-6.5-fold increase of enzyme activity without addition of any artificial cofactors. Isoproterenol was more potent in stimulating the enzyme system than epinephrine and nor-epinephrine. Propranolol caused a dose-dependent rightward shift of the log-dose response curve of these beta-adrenergic agonists. The assay of human fat cell adenylate cyclase in vitro may provide a simple anc convenient assay system for the screening of beta-adrenergic drugs of potential therapeutic importance.

Unchanged hormone sensitivity of rat fat cell adenylate cyclase in uremia

The sensitivity to hormones of the fat cell adenylate cyclase system was tested in uremic rats and in pair-fed control animals. Basal enzyme activities averaged 1.25 nmoles of cAMP formed per mg protein per 15 min in controls compared to 1.30 nmoles cAMP/mg protein/15 min in fat cell ghosts obtained from uremic rats. NaF caused an approximately 4-fold stimulation of enzyme activities in both systems. It was shown that parathyroid hormone should be included amongst the hormones which act as stimulators of the enzyme system. The responsiveness of the rat fat cell adenylate cyclase system towards saturating concentrations of ACTH, glucagon, epinephrine and parathyroid hormone was not altered in the presence of chronic renal failure.

Effects of clofibrate on the human fat cell adenylate cyclase system

The effects of chlofibrate on the adenylate cyclase system of human adipocytes were studied. Clofibrate reduced basal as well as hormone-NaF)stimulated adenylate cyclase activities to about the same extent (45% inhibition at 1 mg/ml clofibrate). The relative extent of hormonal stimulation was not altered by this compound. The inhibitory action of clofibrate was non-competitive with respect to the substrate ATP and cofactors (Mg2+-ions). Inhibition of enzyme activity was detectable after 2.5 min. Our results suggest that the antilipolytic activity of clofibrate is mediated via inhibition of the catalytic subunit of the fat cell adenylate cyclase.

Adenylate cyclase of human fat cell ghosts. Stimulation of enzyme activity by prostaglandins

It has been shown that the human fat cell adenylate cyclase is activated by prostaglandins. Of the prostaglandins tested the E-type by causing about a 3-fold increase of enzyme activity, was more effective than the F-prostaglandins. Prostaglandin A2 had no stimulatory effect. Activation by prostaglandin E1 was not influenced by beta-adrenergic blockade in contrast to stimulation by epinephrine. Pretreatment of fat cells with trypsin resulted in an abolishment of PTH-sensitivity, but had no effect on prostaglandin responsiveness. These results suggest that the human fat cell adenylate cyclase is coupled to at least three distinct types of hormone receptors.

Alpha1-antitrypsin deficiency with M-like phenotype

A patient with a low serum concentration of alpha1-antitrypsin (0-1 g/l) but with an M-like phenotype is described. Her parents and 2 sibs have a PIM phenotype, but all except the father have approximately half-normal levels of alpha1-antitrypsin: The M-like variant apparently cannot be distinguished from M-alpha1-antitrypsin, when it occurs with M in heterozygotes. The proposita has severe airways obstruction and emphysema, and her father has moderate chronic obstructive pulmonary disease. The mother and 2 sibs are healthy.

Adenylate cyclase of human fat cell ghosts. Stimulation of enzyme activity by parathyroid hormone

Some of the effects of native bovine parathyroid hormone and of the synthetic aminoterminal 1-34 fragment on the adenylate cyclase activity of human fat cell ghosts were studied. Saturating concentrations of both hormone preparations caused a significant increase of enzyme activity by about 200-300%. Guanosine 5'-triphosphate (0.1 mM) inhibited basal enzyme activity but had no substantial effect on parathyroid hormone-stimulated enzyme activity. The guanosine 5'-triphosphate analogue, 5'-guanylyl-imidodiphosphate, produced about a threefold enhancement of basal and parathyroid hormone-stimulated enzyme activities under standard conditions (5 mM Mg+2, 1mM ATP, pH 8.0, 30 degrees C). Activation by parathyroid hormone was not influenced by beta-adrenergic blockade in contrast to stimulation by epinephrine. The sensitivity of the enzyme system to the native and the synthetic parathyroid hormone was, however, abolished after pretreatment of the fat cells with trypsin (1 mg/ml). The stimulatory effects of epinephrine and NaF were not affected by pretreatment with trypsin. The results suggest that human fat cells, like rat adipocytes, contain a multireceptor-coupled adenylate cyclase.

Adenylate cyclase of human gastric mucosa. Stimulation of enzyme activity by histamine and catecholamines

Human gastric mucosal adenylate cyclase has been shown to be sensitive to histamine and catecholamines. Stimulation of enzyme activity by histamine and catecholamines were selectively blocked by cimetidine and propranolol, respectively. Combination of both hormones at maximally effective concentrations were additive, indicating that human gastric mucosa contains at least two separate hormone-sensitive adenylate cyclases.

Topographical studies on histamine- and adrenaline-sensitive adenylate cyclases in gastric and duodenal mucosa of human beings

The distribution of histamine- and catecholamine-sensitive adenylate cyclases in human gastric and duodenal mucosa was studied. Basal enzyme activities averaged 155 pmol cAMP/mg prot./15 min in fundic gastric mucosa, 305 pmol cAMP/mg prot./15 min in the antral and 344 pmol cAMP/mg prot./15 min duodenal mucosa. 1 mM histamine induced a more than 2-fold increase of enzyme activity in fundic homogenates, whereas this secretagogue was nearly ineffective in similar preparations from the antral region (1.2-fold increase of enzyme activity). The response towards adrenaline was virtually identical in fundic and antral mucosa preparations. The duodenal enzyme was insensitive toward this catecholamine as well as to histamine. The data are suggestive for a messenger function of cAMP in histamine-stimulated gastric acid secretion.

Catecholamine-sensitive adenylate cyclase of human fat cell ghosts. Characteristics of the GMP(PNP)-liganded state

The effects of 5'-guanylyl-imidodiphosphate (GMP(PNP)) on the catecholamine-sensitive adenylate cyclase of human fat cell ghosts were studied. The compound increased basal and epinephrine-stimulated enzyme activity by about 300%; in addition GMP(PNP) increased hormone sensitivity by reducing the epinephrine concentration required, to produce half maximal stimulation. The rate of GMP(PNP)-induced activation was slow in onset and could be enhanced by epinephrine. The GMP(PNP)-activated state was resistant to thermal inactivation and could not be reversed by extensive washing. The application of this compound in clinical studies may be useful because of its stimulating and stabilizing action.

[The role of HCO3- ATPase in H+ /HCO3-Secretion (author's transl)]

Active buffer transport, e.g. H+ -secretion by stomach and kidney and HCO3--secretion by pancreas and salivary glands, is linked with the presence of a HCO3-stimulated ATP-Phosphohydrolase. In contrast to (Na+ -k+)-ATPase which is considered to be equivalent to the Na+ pump, the HCO3--ATPase requires only one ion for activation and is insensitive to ouabain. The HCO3--ATPase is found in the plasma membrane of the epithelia, but in contrast to the (Na+ -k+)-ATPase it is located in the luminal cell border. The activity of the HCO3--ATPase changes in parallel along with the rate of active buffer transport, a finding which underlines its importance as a transport enzyme. Several disorders of buffer transport are described which are possibly associated with a defect of the HCO3--ATPase system.

Membrane SH-groups related to adrenaline action in rat adipocytes: a comparative study using sulfhydryl reagents of different molecular size

The orientation of SH-groups within the fat cell membrane involved in adrenaline (and NaF) action was studied by comparing the effects of uncoupled p-CMB with those of a large derivative of this reagent -- p-CMB-dextran --. Preincubation of intact adipocytes with uncoupled p-CMB caused a dose-dependent inhibition of adrenaline (and NaF) stimulated adenylate cyclase activity as determined in ghosts prepared subsequently. Preincubation with p-CMB-dextran, however, influenced neither the lipolytic response to adrenaline nor the catecholamine (and NaF) activated adenylate cyclase activity. When p-CMB-dextran was present during ghost preparation, a dose-dependent inhibition of adrenaline (and NaF) stimulated adenylate cyclase activity was observed. These results suggest that the binding sites of adrenaline as well as SH-groups essential for activity of adenylate cyclase are not localized near enough to the exterior surface to be accessible for p-CMB-dextran. The polarity in the sensitivity of fat cell adenylate cyclase could not be observed when p-CMB-dextran was added directly to intact or fragmented ghosts. The abbreviations used are: Cyclic AMP, cyclic adenosine 3',5'-monophosphate; p-CMB, p-chloromercuribenzoate.

Non-specific inhibition of membrane-ATPase by amiloride: a comparative in vivo and in vitro study with ouabain

The submaxillary duct epithelium, which actively transports Na+ (rabbit) and, in addition, K+ and H+/HCO-/3 (rat), was used as a model epithelium to compare the effects of ouabain and amiloride on transport parameters. 1. Ouabain was only effective from the interstitial side, amiloride, however, only from the luminal side. Amiloride induced effects on transport of the ions were seen within less than 1 s, ouabain effects, however, only after minutes. 2. Ouabain inhibited in a parallel fashion the Na+ transport potential and the Na+-K+-ATPase activity. It had no effect on the Mg2+-ATPase and the HCO-/3-ATPase. 3. Amiloride also inhibited the Na+ transport potential and the Na+-K+-ATPase; however, the Na+ transport potential was significantly more sensitive to amiloride than the Na+-K+-ATPase. 4. Amiloride inhibited in a similar fashion the Na+-K+-ATPase, the Mg2+-ATPase and the HCO-/3-ATPase, but did not influence active HCO-/3 secretion. 5. It is concluded that the amiloride induced effects on the membrane ATPases are non-specific.

[Panarteritis nodosa-Special aspects of glucocorticoid and immune suppressive therapy (author's transl)]

Report dealing with the clinical and pathoanatomical course as well as the autopsy findings in a 54 year old female suffering from panarteritis nodosa. Onset of the illness with polyneuritis and arthralgia. One year later diagnosis of panarteritis nodosa verified by muscle biopsy. Deterioration of the disease leading to the development of peripheral gangrene could not be prevented in spite of intensive therapy with steroids, immune suppressive agents, digitalis and antihypertensive drugs. Death 4 years later by myocardial infarction. Autopsy revealed generalized healed panarteritis nodosa with scarring and obliteration of vessels. A short description of the symptoms of the disease is given and the efficacy of the therapy with steroids and immune suppressive drugs is discussed from the clinical as well as the pathoanatomical point of view. Immunopathologic mechanisms are considered to be the responsible factors for pathogenesis.

Effects of SH-reagents of different molecular size upon glucose metabolism in isolated rat fat cells

To study the role of membrane SH-groups in glucose transport of isolated rat fat cells we compared the effects of a small organic mercurial reagent p-CMB with those of a large p--CMB-derivative -- p-CMB-Dextran, MW 10.000 --. It could be shown that both compounds were of almost identical reactivity on fat cell homogenate metabolism. When applied to intact fat cells uncoupled p--CMB showed an (1) insulin like enhancement of 14C incorporation from (U-14C) glucose into CO2 and triglyceride, (2) inhibition of the insulin-stimulatory effect on these parameters and (3) inhibition of basal glucose uptake dependent on the concentrations used. Identical concentrations of p-CMB-Dextran, however, failed to influence basal glucose uptake as well as the insulin mediated increase in glucose metabolism.

[Fistulae in esophageal surgery. (Solidity of the esophageal wall and the role of infection)]

The strength of the eosophageal wall has been tested in 20 autopsy specimens: it proved to be as resistant as the stomach and the jejunum. It dépends as elsewhere in the digestive tract on the deep layer of the mucosa (Halstedt's submucosa): the success of an anastomosis depends on the passage of sutures through this submucosa. Vascularization does not seem to be a problem, provided certain precautions are taken. The necrotizing properties of saliva and infection especially in cancerous surgery might be the main causes of fistulas.

Amplification of the bradykinin response in rat uterus by pCMB-Dextran T 10

pCMB-Dextran T 10,a large, non-penetrating SH-blocking reagent caused a reversible amplification of bradykinin sensituvity in the isolated rat uterus. High concentrations of this compound (1 x 10-3 M) can evoke spontaneous uterus contraction. pCMB-Dextran T 10 did not alter the biological activity of bradykinin. It is assumed that superficial membrane SH-groups are involved in the uterus contraction mechanism.

p-CMB-dextran T 10. A useful tool in evaluating the functional importance of superficial SH-groups in rat adipocytes

A large SH-blocking reagent p-CMB-dextran T 10 (MW about 10,000) was applied to isolated rat adipocytes. This compound possesses the same reactivity towards SH-groups as uncoupled p-CMB. P-CMB-Dextran T 10 did not influence the basal glucose uptake in contrast to uncoupled p-CMB. The results are discussed with respect to the usefulness of p-CMB-dextran T 10 in evaluating the role of superficial SH-groups in various membrane functions.