Experimental models for prevention of graft-versus-host reaction in bone marrow transfusion. I. Selective suppression and augmentation of splenomegaly and cytotoxicity

Induction and suppression of splenomegaly and cytotoxicity against C57BL/L cells were studied in (AKR X C57BL/6) F1 hybrid adult mice after the transfer of AKR lymphoid and bone marrow cells. 1) Splenomegaly and cytotoxicity were dissociated in the developmental stages of the graft-versus-host reaction. When lymphoid and bone marrow cells of normal AKR mice were injected into F1 recipients, splenomegaly was prominent on days 5 and 7, but cytotoxicity of spleen cells was not detected. Splenomegaly became less prominent but the cytotoxicity became detectable on day 14 after the injection. 2) Cytotoxic activity of spleen cells of F1 recipients was suppressed by the treatment of AKR donors with C57BL/6 lymphoid cells in Freund's complete adjuvant. Splenomegaly, however, was substantially enhanced by such a treatment of the donors. On the other hand, induction of the cytotoxic activity was facilitated by the treatment of donors with C57BL/6 skin grafts. 3) F1 hybrid mice could be protected from the graft-versus-host reaction by the injection of AKR anti-C57BL/6 serum or pretreatment of AKR donors with sonicated cellular antigens of C57BL/6.

Interaction of dopamine, methyldopa and reserpine in the sympatho-adrenal system in essential hypertension

1. The interactions of dopamine, reserpine and methyldopa on blood pressure of normal subjects and of those with essential hypertension were examined. 2. When biosynthesis of noradrenaline from dopamine was blocked by reserpine, dopamine induced a prominent depressor effect in essential hypertension. 3. The long-term treatment with methyldopa induced a marked potentiateion of the pressor action of domapine in hypertension, although no significant pressor response was found in normal subjects. 4. It is suggested that methylnoradrenaline may accumulate in peripheral nerve endings of patients with essential hypertension in comparison with normal subjects, and this accumulated methylnoradrenaline potentiates the pressor response to dopamine in essential hypertension.

The properties and connections of nerve cells in leech ganglia maintained in culture

Segmental ganglia of the central nervous system of the leech were maintained in culture medium outside the animal for several weeks at 16°C, and electrical recordings made from identified sensory and motor nerve cells. Ganglia were isolated and cultured singly, in chains and connected to the skin and muscles they normally innervate. Such preparations are suitable for a study of relatively long-term changes that occur as a result of denervation. The changes resemble those seen in isolated ganglia that had been kept in situ in the animal. (1) Resting and action potentials in sensory and motor neurones of isolated ganglia appear normal for up to ten weeks. The same cells can be tested at intervals of a few days. (2) Sensory cells, classified as touch (T), pressure (P) or nociceptive (N) according to their morphology and electrical properties, continue to respond selectively to stimuli of the appropriate modality applied to their receptive fields in the skin; action potentials in motor cells cause contractions in the appropriate muscles. (3) Chemical synaptic transmission between sensory and motor nerve cells changes markedly over the first three weeks; excitatory and inhibitory synaptic potentials can double in size and duration over a period of about two weeks in culture. (4) The balance between excitatory and inhibitory synaptic influences changes sequentially after isolation in culture. For example, P or N cells innervating a cell which erects skin annuli normally cause small depolarizing excitatory potentials. After 5 days in culture they initiate large inhibitory synaptic potentials, while by 15 days the balance between excitation and inhibition changes again, so that the predominant synaptic action is an abnormally large prolonged excitatory potential. (5) After more than three weeks synaptic potentials disappear and ganglia lose transparency. (6) The morphological appearance of T, P and N sensory cells has been compared in cultured and normal ganglia after injection of horseradish peroxidase. In cultured ganglia the major branching pattern appears normal but presumed sites of transmitter release become more conspicuous.

Lack of cytochalasin E-induced superoxide release by polymorphonuclear leucocytes of patients with chronic granulomatous disease: a new diagnostic test

Reduction of exogenous cytochrome c was induced by the treatment of human polymorphonuclear leucocytes with cytochalasin E. The reduction was completely inhibited by superoxide, dismutase, indicating that superoxide anions were released from the cells. The leucocytes from two patients with chronic granulomatous disease did not show the release reaction that should have been brought on by the treatment. The cytochalasin-induced reduction of exogenous cytochrome c by polymorphonuclear leucocytes is so specific and sensitive that it seems to be useful for diagnosis of chronic granulomatous disease.

Potassium current and the effect of cesium on this current during anomalous rectification of the egg cell membrane of a starfish

The kinetics of the membrane current during the anomalous or inward-going rectification of the K current in the egg cell membrane of the starfish Mediaster aequalis were analyzed by voltage clamp. The rectification has instantaneous and time-dependent components. The time-dependent increase in the K conductance for the negative voltage pulse as well as the decrease in the conductance for the positive pulse follows first-order kinetics. The steady-state conductance increases as the membrane potential becomes more negative and reaches the saturation value at about -40 mV more negative than the K equilibrium potential, V(K). The entire K conductance can be expressed by g(K).n; g g(K) represents the component for the time-independent conductance which depends on V-V(K) and [K+]o, and n is a dimensionless number (1 is greater than or equal to n is greater than or equal to 0) and determined by two rate constants which depend only on V-V(K). Cs+ does not carry any significant current through the K channel but blocks the channel at low concentration in the external medium. The blocking effect increases as the membrane potential is made more negative and the potential-dependent blocking by the external Cs+ also has instantaneous and time-dependent components.

Comparison of progenitor toxins of nonproteolytic with those of proteolytic Clostridium botulinum Type B

A nonproteolytic strain of Clostridium botulinum type B produces two toxins of different molecular weight (16S and 12S) that are indistinguishable from the corresponding toxins of a proteolytic strain in molecular weight and construction but differ in potential toxicity, activation ratio, and hemagglutinability. Successful hybridization between the toxic and nontoxic components (both7S) of 12S toxins of biologically heterologous type B strains confirmed the physico-chemical similarity between the toxic as well as the nontoxic components.

Elevated plasma renin activity in aortitis syndrome

Plasma renin activity (PRA) was measured in 38 cases of aortitis syndrome. The values of resting peripheral vein blood PRA were 32.2 +/- 4.2 (SE) mmug/ml. These values were 3 times higher than those of normal subjects. Hypertension due to renal arterial stenosis was observed in 18 cases. Their resting PRA values were 41.2 +/- 6.0 mmug/ml, while in the remaining 20 patients without renovascular hypertension those values were 24.2 +/- 5.4 mmug/ml. The patients belonging to aortic arch type or extensive type had 2 times higher PRA values than those of abdominal type. The patients with stenosis or obstruction of common carotid arteries had significantly higher PRA values than the patients without these lesions. Hyperresponse of renin secretion to upright posture was also observed in the same patients with carotid artery stenosis. Abnormal renin release in Takayasu's arteritis disappeared after denervation of the carotid sinus nerve. The present study suggests that the unstable state of carotid sinus reflex is the main cause for the hypersecretion of renin.

Postoperative course of blood pressure and plasma renin activity in patients with renovascular hypertension

Thirty patients with renovascular hypertension were treated surgically, and they were divided into two groups according to the kinds of operations they received; nephrectomized group (group A) and revascularized group (group B). Postoperative blood pressure was followed periodically in each patient of two groups. In all patients with an excellent result (diastolic pressure of 90 mmHg or lower without antihypertensive therapy), blood pressure returned to normal within 30 postoperative days. Normal blood pressures were obtained within 3 weeks in eighty-four per cent of them. The normalization of blood pressure following operation was more rapid in group B than in A. The postoperative plasma renin activity (PRA) was determined serially in 10 patients. PRA became normal in 9 within 3 days and in one within 7 postoperative days. The restoration of PRA preceded the normalization of blood pressure. The normalization of PRA was quicker in group A than in B. It is likely that the renal antihypertensive mechanism, suppressed in the ischemic kidney and set again in motion by revascularization, mainly causes this difference in the postoperative changes in PRA and blood pressure between the two groups. It may be concluded that these findings are suggestive of an important role of impaired renal antihypertensive function in the maintenance of high blood pressure in chronic renovascular hypertension in man.

Modification and regeneration of synaptic connections in cultured leech ganglia

Segmental ganglia of the central nervous system of the leech were maintained in culture medium outside the animal for several weeks in order to study the properties of synapses and regeneration by identified sensory and motor nerve cells. A variety of preparations were used, including single ganglia, chains of ganglia and ganglia connected to the areas of skin and muscle that they normally innervate in the animal. (1) For up to 10 weeks after removal from the animal, resting and action potentials recorded from sensory and motor neurons resembled those seen in normal ganglia. The same individual cell in a cultured ganglion could be recorded from with intracellular electrodes on a second occasion after an interval of a few days. (2) Sensory cells, identified as touch, pressure or nociceptive according to their morphology and electrical properties, continued to respond selectively to stimuli of the appropriate modality applied to their receptive fields in the skin; action potentials in motor cells caused contractions in the appropriate muscles. Culture of ganglia for more than 3 weeks caused the disappearance of synaptic potentials and a loss of transparency in ganglia. (3) Certain chemically mediated synaptic interactions between sensory and motor nerve cells became markedly changed in cultured ganglia. These changes appeared over the first 3 weeks and consisted of abnormally large excitatory and inhibitory synaptic potentials. The changes in synaptic transmission observed in culture were in many respects similar to those occurring in ganglia maintained within an animal after lesions have been made in the nervous system (Jansen et al. 1974). (4) The morphological appearances of sensory cells were compared in cultured and normal ganglia after injection of horseradish peroxidase. In cultured ganglia, the branching pattern appeared normal, but varicosities became more conspicuous. (5) When connectives linking cultured ganglia were crushed or cut, regeneration occurred. By 7 days, impulses propagated through the regenerated fibers and evoked synaptic potentials on cells within the next ganglion. The course taken by regenerating axons was observed in cells injected with horseradish peroxidase. The results again resembled those seen in animals with similar lesions. (6) The cultured ganglia provide preparations in which it is possible to analyze the mechanisms that underlie long-term changes similar to those seen in the leech central nervous system in situ.

Renal effects of prostaglandin E1 in hypertensive patients

The effects of prostaglandin E1 on fluid and sodium excretion, creatinine clearance and renin release were examined in 26 hypertensive patients including 9 cases of essential hypertension, 10 of renovascular hypertension and 7 of primary aldosteronism. When prostaglandin was infused intravenously in a total dose of 120 mug in 60 min, urine volume was increased in 70% of cases, and sodium excretion in 61%, but little changes were observed in creatinine clearance. The most prominent diuresis and natriuresis were obtained in primary aldosteronism (mean increase was 319% in urinary volume, and 222% in sodium output). The average increases in urinary volume were 61% in patients with essential hypertension and 97% in renovascular hypertension. And urinary output of sodium was increased by 63% in the former and 56% in the latter. The remarkable renal effects of prostaglandin E1 in primary aldosteronism were completely abolished after the administration of spironolactone. Significant elevation of plasma renin activity resulted from prostaglandin E1 infusion in essential hypertension, while no constant effect was obtained in renovascular hypertension and primary aldosteronism. The present experiments indicate that prostaglandin E1 has different effects on the kidney according to the types of hypertension and the effects correlate closely with patient's status of extracellular fluid volume or sodium balance.

Calcium and sodium contributions to regenerative responses in the embryonic excitable cell membrane

Ionic dependence of regenerative responses of the embryonic cell mnembrane has been studied successively at each stage of development from the unfertilized egg to the differentiated striated muscle in the tadpole larva of the tunicate. The unfertilized egg cell itself showed a type of regenerative response dependent on both sodium and calcium ions, while the spike potentials exclusively dependent on calcium ions were elicited in the differentiated muscle cell.

Metabolism of 14C-chlorobenzilate and 14C-chloropropylate by Rhodotorula gracilis

Rhodotorula gracilis metabolizes Chlorobenzilate (ethyl 4,4'-dichlorobenzilate) and Chloropropylate (isopropyl 4,4'-dichlorobenzilate) to several metabolites in a basal medium supplemented by sucrose and by several intermediates of the citric acid cycle. Three identified metabolites resulting from the degradation of either acaricide, were 4,4'-dichlorobenzilic acid, 4,4'-dichlorobenzophenone, and carbon dioxide. Chlorobenzilate, i.e., ethyl ester of 4,4'-dichlorobenzilic acid, was more easily hydrolyzed than Chloropropylate, i.e., isopropyl ester of this acid, so that larger amounts of carbon dioxide and 4,4'-dichlorobenzophenone were obtained from Chlorobenzilate degradation. Regardless of acaricides used, longer incubation caused a higher accumulation of 4,4'-dichlorobenzophenone. The probable steps of the degradation pathway are: Chlorobenzilate (or Chloropropylate) --> 4,4'-dichlorobenzilic acid --> 4,4'-dichlorobenzophenone plus carbon dioxide. It appears that the decarboxylation of 4,4'-dichlorobenzilic acid to 4,4'-dichlorobenzophenone was hindered by alpha-ketoglutarate and enhanced by succinate.