Sarcoid encephalopathy with diffuse inflammation and focal hydrocephalus shown by sequential CT

Sequential computerized tomography (CT) was performed on a patient with seizures and an organic mental syndrome. Cerebral sarcoidosis was subsequently diagnosed on the basis of noncaseating granulomas in three organ systems. Cranial nerve palsies, hypothalamic dysfunction, and widespread disease were absent. An unusual neuroradiologic sequence of events indicated focal and asymmetric hydrocephalus, mass effect, ependymitis, diffuse breakdown of the blood-brain barrier, and periventricular white matter destruction. These findings have not been previously described together in a patient with sarcoid. With the advent of noninvasive CT, it is possible to perform serial investigations of encephalopathies of obscure origin. Findings similar to those in the present case should prompt a thorough search for subclinical systemic involvement by sarcoid.

Murine cytomegalovirus-induced protein synthesis

Murine cytomegalovirus (MCMV)-induced protein synthesis in mouse embryo fibroblast (MEF) cells was studied using polyacrylamide gradient SDS gel electrophoresis and autoradiography. Synthesis of at least 14 virus induced proteins (VIPs) was consistently detected in a lytic cycle. They were designated VIPs 132, 118, 99, 98, 88, 81, 76, 74, 58, 56, 51, 38, 36 and 33 on the basis of their mol. wt. Judging from the pattern of the rate of protein synthesis, VIPs can be classified into three groups: group A VIPs were synthesized actively for a brief period of time and then their synthesis was no longer detectable. This group included two major VIPs, 98 and 88 and three minor VIPs, 58, 56 and 38. Group B VIPs 81, 74, 36 and 33 were similar to group A except that, following a brief period of active synthesis, a low level of synthesis continued during the entire lytic cycle. Group C VIPs 132, 118, 99, 76 and 51 were synthesized at low steady levels at all times after initiation and seemed to accumulate slowly. According to temporal sequences of initiation of VIP synthesis, these proteins can also be divided into three groups: immediate early, early and late VIPs. The synthesis of the immediate early VIPs 132, 98, 88, 81, 76, 74 and 38 was initiated immediately after virus infection. The early VIPs included 58, 56, 51, 36 and 33 and their synthesis was initiated from 1 to 3 h post-infection. VIPs 118, 99 and several minor VIPs were first synthesized during 12 to 13 h post-infection which corresponded to the time of initiation of virus DNA synthesis and they are classified as late VIPs. Cycloheximide reversal experiments indicated that the initiation of synthesis of early VIPs must be preceded by the synthesis of immediate early VIPs. In the presence of actinomycin D, the immediate early VIPs (0 to 1 h post-infection) were not synthesized indicating that immediate early VIPs are translated from virus mRNA synthesized after virus infection.

Reduced response of plasma aldosterone to acute ACTH stimulation during long-term treatment with spironolactone in essential hypertension

The response of plasma aldosterone (PA) to ACTH administration (250 micrograms alpha 1-24 ACTH i.m.) before and during treatment with spironolactone (Sp, 75--100 mg/day) for at least 8 months was studied in 11 patients with essential hypertension. These responses were compared with those before and during prolonged treatment with hydrochlorothiazide (Th, 50--75 mg/day), with or without potassium supplement, in 14 hypertensives. PA and plasma cortisol (PC) were determined by radioimmunoassay in which Sp showed minimal cross-reactivity. Both Sp and Th treatments caused similar increases in plasma renin activity accompanied by nearly identical decreases in blood pressure and body weight. PA was also increased by both treatments, but to a significantly greater extent in the Sp-treated group. Serum potassium concentration was increased only by Sp treatment. The response of PA, but not of PC, to acute ACTH stimulation was blunted in the Sp-treated group. That is, the maximal increment of PA above the baseline level was significantly lower during Sp treatment than either before Sp treatment of during Th treatment. These results demonstrate that long-term treatment with Sp can inhibit aldosterone production by acute ACTH stimulation in patients with essential hypertension.

Inactivation of cytomegalovirus and Semliki Forest virus by butylated hydroxytoluene

Butylated hydroxytoluene (BHT) is an antioxidant that is widely used in foods because it prevents spoilage by delaying degradation of lipid components. This hydrophobic compound inactivated human and murine cytomegalovirus (CMV) and Semliki Forest virus (SFV). Both human and murine CMV were inactivated more than 90% by 40 microgram of BHT/ml after incubation for 1 hr at 37 C. Under the same conditions, SVF was inactivated about 75%, whereas poliovirus, which does not contain lipid membrane as a part of its structure, was not inactivated at all. Vaccinia virus was less sensitive to BHT than was CMV or SFV.

Computed tomography in isodense subdural hematoma

Isodense subdural hematomas, particularly bilateral ones, may be difficult to diagnose with CT. Forty-three cases of subdural hematomas were studied by CT, 7 of which were isodense collections. Obliteration or displacement of the cortical sulci in the zone of the extracerebral collection was present in all 7 cases. Infusion scans demonstrated displacement of a cortical vein away from the inner table of the skull in 3 of the 7 cases. This findins is helpful in accurately predicting the size of the extracerebral collection.

Alteration by cereolysin of the structure of cholesterol-containing membranes

When erythrocyte membranes were treated with cereolysin, negatively stained and examined by electron microscopy, ring and arc-shaped structures were observed in the membrane. The outside diameter of the rings varied from 33 to 50 nm with a border thickness of 6.7 to 8.3 nm. The arcs varied in length from 33 to 170 nm with a border thickness of also 6.7 to 8.3 min. When right-side-out erythrocyte ghosts which had been treated with cereolysin were examined by electron microscopy after freeze-fracture, structures with a diameter of 31 to 63 nm were seen in the fracture face of the exoplasmic half of the membrane, but no alterations were visible in the fracture face of the protoplasmic half of the membrane bilayer. Thus the ring structures did not appear to form holes through the membrane. At cereolysin concentrations above 6 microgram/ml rings and arcs were seen when purified toxin alone was examined. At or below 6 microgram/ml toxin rings and arcs were seen only if toxin was incubated with free or membrane-bound cholesterol. Our interpretation is that cereolysin tends to aggregate into ring and arc-shaped structures, and that the tendency to aggregate is increased by cholesterol. Rings and arcs were not seen when erythrocyte ghosts were treated with low, but lytic amounts of cereolysin that significantly altered the premeability of the ghosts.

Intradiploic neural heterotopia. A rare calvarial defect

Two proved cases of intradiploic neural heterotopia of the skull, a rare cause of calvarial defects, are presented. The literature is reviewed. Common radiographic characteristics include an intradiploic rarefaction, a well-defined margin with or without sclerosis, a lobulated appearance with normal intervening bone, or a cluster of multiple lytic areas with normal bone between them.

Interaction between sphingomyelin and a cytolysin from the sea anemone Stoichactis helianthus

The cytolytic toxin from the sea anemone Stoichactis helianthus was inhibited up to 90--95% by suspensions of sphingomyelin but not by phosphatidylcholine or other membrane lipids. When the toxin was incubated with sphingomyelin and the mixture fractionated either by isoelectric focusing or Sephadex gel filtration, the residual hemolytic units migrated together with the lipid and not as free toxin. Incubation with phosphatidylcholine, however, did not shift the toxin peak in either type of column. A toxin-ferritin conjugate retaining hemolytic activity was observed by negative staining to bind to liposomes prepared with sphingomyelin but not with liposomes containing phosphatidylcholine. The results provide evidence that the membrane binding site of the toxin is sphingomyelin.

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Complement-fixing antigen of human cytomegaloviruses

The titer of complement-fixing (CF) antigen of human cytomegalovirus (CMV) strain C87 was not reduced by 10 cycles of freezing and thawing or by storage at 4 C for two months, although the virus was labile at 37 C and 100 C. The rapid increase in titers of CF antigen and plaque-forming units was seen from days 3 through 6 after infection; however, CF antigen was detected 24 hr after infection. The molecular weight of CF antigen was estimated by gel filtration to be greater than 1.5 X 10(7) daltons. Electrophoresis of CF antigens from five strains of human CMV (AD169, C87, Espilant [Esp.], Davis, and Towne) in a gradient polyacrylamide gel slab in the presence of sodium dodecyl sulfate revealed two specific polypeptides with molecular weights of 140,000 and 66,000 daltons, respectively. The smaller polypeptide was glycosylated. Preparations of CF antigen from murine CMV and herpes simplex virus type 1 contained polypeptides of 140,000 and 145,000 daltons, respectively. However, the polypeptide with a molecular weight of 66,000 daltons was seen only in preparations of human CMV.

Analysis of structural polypeptides of purified human cytomegalovirus

Human cytomegalovirus strain C87 was purified by the following procedures. (i) Extracellular virus was concentrated by centrifugation at 100,000 X g for 90 min and passed through a Bio-Rad Bio-Gel A-15m column. Most of the virus was recovered in the void volume. (ii) After two consecutive isopycnic potassium tartrate gradient centrifugations (20 to 50%), coinciding peaks of plaque titer, protein, and radioactivity were found at a density of from 1.20 to 1.21 g/cm3. To characterize the structural polypeptides of human cytomegalovirus and to establish relative purification criteria, virus was purified from two mixtures: (i) [35S]methionine-labeled extracellular virus mixed with an equal volume of unlabeled normal culture fluid; (ii) unlabeled extracellular virus mixed with an equal volume of [357a1methionine-labeled normal culture fluid. The extent of purification, as judged by the ratio of cellular to viral radioactivity, was 39-fold; i.e. about 2.5% of the protein in the purified virus preparation could be accounted for by host protein contamination. Electrophoresis of purified [35S]methionine-labeled virus on a polyacrylamide gel slab showed that there were at least 33 viral structural polypeptides (VPs), and their molecular weights ranged from 11,000 to 290,000. Autoradiograms obtained from electropherograms of purified [14C]glucosamine labeled virus showed six bands. Four of these were so broad that several VPs corresponded to each of the glycosylated bands. When heavy (two fractions close to 1.21 g/cm3) and light (two fractions close to 1.20 g/cm3) fractions of the PFU peak from the second potassium tartrate gradient were analyzed separately, the number of polypeptides observed was the same, but the relative amounts of some polypeptides differed. The major polypeptide, VP17, was found in greater amounts in the heavy fraction (35%) than in the light fraction (22%). The amount of DNA as a percentage of the weight of protein was 2% for the light fraction and 1% for the heavy fraction.

Axonal transport of [3H]serotonin in an identified neuron of Aplysia californica

A population of characteristic ellipsoidal dense-core vesicles was identified in axons of the giant cerebral neuron of the mollusc Aplysia. We injected [3H]serotonin into the cell body of this identified serotonergic neuron in the isolated central nervous system in order to study the subcellular components associated with the neurotransmitter. Subcellular fractionation by differential centrifugation indicated that injected serotonin was rapidly taken up into particulate form. [3H]Serotonin appeared in the axons within 2 h after injection, and export continued at a constant rate of 6% of the total in the neuron/h thereafter. The dependence of the total amounts of [3H]serotonin which appeared in the axons in 6 h (export from the cell body) on the amounts injected was consistent with the idea that export is a saturable process, possibly depending on the capacity of somatic vesicles or of some unidentified carrier for serotonin. [3H]Serotonin moved into both major branches of the axon, where it was translocated rapidly. The transmitter, which was shown by autoradiography to be restricted to the axons of the injected cell, was distributed along axons in accumulations of radioactivity; in contrast, its precursor, [5-3H]hydroxytryptophan, moved slowly along axons in a smooth, declining curve, its kinetics consistent with diffusion. Quantitative electron microscope autoradiography revealed that the dense-core vesicles and the cytosol of axons fixed with glutaraldehyde were labeled with [3H]serotonin.

Effect of a spironolactone derivative (SC 14266) on Plasma renin activity in adrenal regeneration hypertension

The effects of treatment with a spironolactone derivative (SC 14266) for 9 experimental weeks on blood pressure and plasma renin activity (PRA) were investigated in unilaterally nephroadrenalectomized rats drinking 1% saline ("unilater nephrectomy"), unilaterally nephroadrenalectomized and contralaterally adrenal-enucleated rats drinking 1% saline ("adrenal enucleation") and intact rats drinking tap water ("normal"). The development of hypertension in "adrenal enucleation" rats was prevented by treatment with SC 14266 and the drug did not significantly affect the blood pressure in either "unilateral nephrectomy" or "normal" rats. SC 14266 did not influence a low level of basal PRA and the blunted response of PRA to furosemide administration in either "unilateral nephrectomy" or "adrenal enucleation" rats. On the other hand, PRA after furosemide administration in "normal" rats receiving SC 14266 was significantly higher than that in those rats treated with vehicle. The results suggest that the mineralocorticoid(s) secreted by the enucleated adrenal has a hypertensogenic property but no effect on the suppression of renin secretion under a high sodium intake and the unilateral nephrectomy.

Analysis of structural proteins of purified murine cytomegalovirus

Murine cytomegalovirus propagated in mouse embryo fibroblasts was purified by the following procedures. (i) Extracellular virus was concentrated by centrifugation at 100,000 x g for 90 min. (ii) The concentrated virus was passed through a Bio-Rad Bio-Gel A-15m column to eliminate contaminating materials smaller than 15 x 10(6) daltons. Most of the virus was recovered in the void volume of the column. (iii) Two consecutive centrifugations through 20 to 50% potassium tartrate gradients were performed. After the second tartrate gradient centrifugation, symmetrical, coinciding peaks of plaque titer, protein, and radioactivity were found at a density between 1.20 g/cm3 and 1.21 g/cm3. To establish purification criteria, virus was purified from two different mixtures: [35S]methionine-labeled extracellular virus, mixed with an equal volume of unlabeled normal culture fluid, and unlabeled extracellular virus mixed with an equal volume of [35S]methionine-labeled normal culture fluid. At the end of the procedure, the extent of purification, as judged by the ratio of cellular to viral radioactivity was at least 70-fold. Virus proteins were analyzed by electrophoresis on a 5 to 20% gradient polyacrylamide gel slab. After gel electrophoresis,, Coomassie brilliant blue staining profiles and autoradiograms of the purified virus preparations were compared. At least 33 virus structural protein bands were present. The molecular weights of these proteins ranged from 11,500 to 255,000. The sum of the molecular weights of the virus structural proteins was 2,462,000. Autoradiograms obtained from electrophoresis of purified [14C]glucosamine-labeled virus showed that at lease 6 of the 33 viral structural proteins were glycoproteins.

Angiographic features of subdural empyema

Subdural empyema, a relatively rare intracranial suppurative disease, is a surgical emergency and requires early diagnosis in order to ensure patient survival. Subdural empyema should be considered with one or a combination of the following in conjunction with an extracerebral collection: (a) an irregular border of the extracerebral collection; (b) a thickened vascular wall of dura; (c) a semilunar avascular zone on the lateral view; (d) spasm of the large arteries at the base of the brain with or without segmental arterial dilatation; (e) multiple peripheral arterial occlusions; and (f) enlargement of the anterior falx artery. Four verified cases are presented.

Ultrastructure of superficial mycosidic integuments of Mycobacterium sp

Cells from pellicle growth of Mycobacterium sp. NQ are enveloped in a mycoside layer which extends outward as long filaments, 5 nm in diameter. Underneath this outer mycosidic casement, ramified ropelike structure, embedded in a dense matrix, overlay the rigid peptidoglycan of the cell wall.