[New developments relating to papillomaviruses].

Molecular hybridization technique and immunofluorescence studies with use of specific immune sera against the purified virions isolated from various types of warts and wart-like lesions of epidermodysplasia verruciformis (EV) made it possible to detect four different types of human papilloma viruses (HPV). The recognition of the viruses is important because of the different morphology of the lesions induced and their various oncogenic potentials. HPV1 is mainly responsible for plantar warts, HPV2 for common (hand) warts, HPV3 has been found both in flat warts and in the variety of EV in which skin lesions are of flat wart type, the course is relatively more benign, and usually malignant transformation is not to be expected. HPV4 was up to now found exclusively in the cases of EV with prevalent red and red-brownish plaques and hyper- and depigmentations similar to those of pityriasis versicolor. In all cases of this variety of EV malignancies occured invariably. In patients with EV, as also in--to a lesser extent--longstanding flat and/or common warts cell mediated immunity was in general lowered, but humoral specific anti-HPV antibodies were usually present. HPV type seems to be of a decisive significance for potential oncogenesis, because in a vast majority of cases EV due to HPV3 no malignancies occured in spite of anergy, whereas malignant transformation has been found in all cases due to HPV4, even in a patient with still preserved, although lowered, CMI.


Aetiology of breast cancer: a brief review.

Cancer of the human breast is probably a group of diseases which have different causes. Changes in hormonal status that increase breast cancer risk probably do so by 'promoting' tumour development rather than by 'initiating' it. Exogenous oestrogens seem to act as tumour promoters in this context, but there is to date no evidence that oral contraceptives, some of which contain oestrogens in low dosage, increase breast cancer risk. On the contrary, they appear to reduce the incidence of benign breast tumours. Prolactin-release is associated with increased mammary tumour incidence in rats but not in humans. There is no evidence that viruses or exposure to hair-dyes increase breast cancer risk. The fact that slight dietary restriction can dramatically reduce mammary tumour incidence in rats, suggests that dietary factors should be looked at more closely in the search for aetiological factors in man.


Oxygen-induced alteration of ventilation-perfusion relationships in rats.

The effect of oxygen breathing on shunt and ventilation-perfusion ratios (VA/Q) in anesthetized rats was studied using a modification of the multiple inert gas elimination technique. Base-line analyses showed hypoxemia in some animals breathing room air (arterial O2 tensions 48-70 Torr) associated with intrapulmonary shunts ranging from 0 to 22%, and variable low VA/Q lung regions as determined by calculation of the inert gas arterial-alveolar difference curve. Of nine rats that breathed 100% oxygen for 30 min, three showed increases in shunt (0% leads to 19%, 1.5% leads to 16%, 11% leads to 40%). These three animals had larger preexisting low VA/Q regions than the six that developed no shunt (0.48 +/- 0.15 vs. 0.17 +/- 0.03 (mean +/- SD); P less than 0.05). These data are compatible with the theory of absorption atelectasis. This study documents the usefulness of the inert gas elimination technique for studying  pulmonary gas exchange problems in small animals.


FIP antibody test--interpretation and recommendations.

It is my opinion that the feline infectious peritonitis (FIP) antibody test currently is being over-used and over-interpreted. The test is of value to the practitioner in specific circumstances, but by itself it is not diagnostic of clinical FIP. Further, it is my opinion that clinically healthy FIP antibody-positive cats should not be euthanatized under a routine test and eradication policy.


Anemia associated with feline leukemia virus infection.

One hundred feline leukemia virus-positive cats with evidence of anemia were examined to determine characteristics of the anemia. The anemia was usually normochromic and normocytic, with low reticulocyte counts but with normal white blood cell and platelet counts. About one third of the cats had splenomegaly. The bone marrow was usually hypocellular or normally cellular, with an increased myeloid to erythroid ratio. A history of recent stress or infection in many cases indicated that the immunosuppressive effect of feline leukemia virus may have been involved. Supportive treatment with periodic blood transfusions was successful in prolonging survival. Corticosteroids and androgens may have been beneficial in some cases.


Synthesis of DNA in the liver and testes of cadmium-tested partially hepatectomized rats.

Cadmium affects the induction of thymidine and thymidylate kinases in regenerating rat liver. EDTA administered simultaneously with cadmium reverses its inhibitory action on enzyme synthesis, and prevents the depression of thymidine incorporation into DNA observed in cadmium-treated animals. Zinc does not abolish the inhibitory action of cadmium on the synthesis of DNA in regenerating liver, and the incorporation of thymidine into DNA in the testes was inhibited more by intraperitoneal injection of cadmium plus zinc than by injection of cadmium alone. Inhibition of thymidine incorporation into DNA in the liver and testes was proportional to the amount of cadmium administered up to about 2 mg CdCl2/kg body weight, but surprisingly, higher doses of cadmium caused less inhibition.


The use of Haemophilus gallinarum DNA-relaxing enzyme to investigate the relationship between the number of superhelical turns and the molecular weight in a negatively twisted DNA.

Covalently closed-circular, superhelical DNAs, including viral DNAs, bacterial plasmid DNAs, and bacteriophage replicative-form DNA, were treated with a small amount of Haemophilus gallinarum DNA-relaxing enzyme to generate incompletely relaxed DNA molecules. Each sample consisted of a set of closed-circular DNA molecules differing by one turn in their number of superhelical turns. The DNA samples were analyzed by agarose gel electrophoresis under conditions such that the electrophoretic mobility was a function of the number of turns. The numbers of superhelical turns (at 37 degrees C in 20 mM Tris-HCl (pH 7.5)-5 mM MgCl2) in the DNAs of pSC101 (5.8 megadaltons), Colicin E1 (4.2 megadaltons), pMR4 (4.0 megadaltons; recombinant between pBR322 and lambda DNA fragment), phi X174 replicative-form (RF) I, Simian virus 40 (SV40), and polyoma virus (3.4--3.6 megadaltons each), and lambda dv021 (2.05 megadaltons) were estimated to be 36, 27, 23--24, 20--21, 20--21, 20--21, and 11--13, respectively. It appears that the number of superhelical turns is mainly a function of the molecular weight of the DNA, at least in the substrates tested here.


Change in the fructose 1,6-bisphosphatase activity in sea urchin eggs following fertilization.

The activity of fructose 1,6-bisphosphatase [EC 3.1.3.11] in sea urchin eggs decreased following fertilization. During the first 30 min after fertilization, the activity was considerably lower than that in unfertilized eggs, but by 30 min the activity was similar to that in unfertilized eggs. The enzyme activity in fertilized eggs, estimated in the presence of EGTA, was similar to that in unfertilized eggs. The activity in unfertilized eggs was reduced by Ca2+ at concentrations between 1 X 10(-5) M and 5 X 10(-3) M. Immediately after fertilization, the enzyme was insensitive to concentrations of Ca2+ lower than 2 X 10(-4) M, but the Ca2+ sensitivity of the enzyme recovered 30 min after fertilization. In the presence of Ca2+ at concentrations higher than 2 X 10(-4) M, the enzyme activity in unfertilized eggs was similar to that in fertilized eggs. Mg2+ restored the Ca2+-induced inhibition of fructose 1,6-bisphosphatase. 3-Phosphoglycerate and citrate hardly affected the enzyme activity, and AMP at concentrations above 10 mM inhibited it.


Transfer of cholestane spin label between lipid bilayer membranes and its molecular motion in membranes.

The relation between the molecular motion of a steroid in lipid membranes and the transfer rate between membranes was examined using radioactive cholestane spin label. Order parameters of the molecule were determined in bilayers composedof dipalmitoylglycerophosphocholine or egg yolk phosphatidylcholine at various temperatures. The line widths of the ESR signal of the cholestane spin label in membranes, which depend upon the rate of molecular axial rotation in the membranes, were also measured. The temperature dependences of these two parameters and of the transfer rate suggest a close correlation between the rate of molecular axial rotation and the transfer rate.


Subunits of cytochrome a-type terminal oxidases derived from Thiobacillus novellus and Nitrobacter agilis.

Cytochrome a-type terminal oxidases derived from Thiobacillus novellus and Nitrobacter agilis have been purified to a homogeneous state as judged from their electrophoretic behavior and their subunit structures studied by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The T. novellus enzyme is composed of two kinds of subunits of 32,000 and 23,000 daltons and its minimum molecular weight is 55,000 on the basis of heme content and amino acid composition. The N. agilis enzyme also has two kinds of subunits of 40,000 and 27,000 daltons and its minimum molecular weight is 66,000 on the basis of heme content and amino acid composition. Therefore, the molecule of each enzyme is composed of two kinds of subunits which resemble the subunits of the eukaryotic cytochrome oxidase biosynthesized in the mitochondrion at least with respect to molecular weight.


Induction of new-bone formation in the host bed by human bone-tumor transplants in athymic nude mice.

Specimens of twelve osteosarcomas, five chondrosarcomas, one giant-cell tumor, and five extraskeletal soft-tissue sarcomas were transplanted into male athymic nude (nu/nu) mice. Survival of the transplant was determined by the volume-doubling time and the sex chromatin of the tumor cells obtained from two female patients. By these criteria and the similarity of the histological composition of the original tumor and the transplant, survival occurred in four of twelve osteosarcomas and four of five chondrosarcomas. Without any local infiltration of lymphocytes or plasma cells, or other evidence of cell-mediated immunity, the surviving tumors regressed by the fourth week after the operation. Transformed osteoblasts and osteoprogenitor cells were replaced by fibrous connective tissue or fibrogenic tumor-tissue cells. Osteocytes degenerated and disappeared from the lacunae. The one giant-cell tumor transplant survived, growing very slowly, but by the end of the first week after transplantation whorls of mononucleated cells appeared in sites previously occupied by multinucleated cells. Transplants of leiomyosarcoma, liposarcoma, and synovioma (one tumor of each) degenerated. One of two fibrosarcomas survived transplantation. The most striking reaction of the mouse host bed was to encompass six of twelve osteosarcomas and four of five chondrosarcomas in deposits of normal living cartilage, bone, and bone marrow. The incidence of new bone inducedy by living transplants was only slightly greater than by implants of freeze-dried killed osteosarcoma tissue. Not one of five extraskeletal sarcomas, living or dead, induced bone formation. These observations suggest that an osteoinductive agent is transmitted by some osteosarcomas and chondrosarcomas. This agent initiates differentiation of host mesenchymal cells into normal non-tumorous cartilage and bone, which later colonized by bone marrow. Our observations present experimental evidence of the origin of the envelope of normal non-tumorous bone that may surround tumorous bone. In 1926, Phemister recognized the clinical significane of this envelope as a pitfall in the differential diagnosis of malignant bone tumors, chondrosarcoma, myositis ossificans circumscripta, and other neoplasms. He emphasized the importance of examining the entire specimen for the distribution of deposits of tumorous and normal bone. The induction of normal bone formation in the host bed surrounding transplants of osteosarcomas and some chondrosarcomas (but not transplants of fibrosarcoma, liposarcoma, or leiomyosarcoma) is evidence of a specific tumor-cell characteristic. Thus, the bone inductive response is not an unspecific reaction to injury from expansion or of tumor growth but a biological response to tumor-cell products. Transplants of human malignant tumors growing in the thymus-deficient mouse can be treated by combinations of radiation, amputation, and new chemotherapeutic agents...


Fibrosarcoma of breast metastatic to stomach.

A case of fibrosarcoma of the breast metastatic to the stomach and small bowel is reported. Upper gastrointestinal bleeding secondary to a "bull's eye" or "target" gastric ulcer was successfully treated by surgical resection.


Reversible accumulation of cholesteryl esters in macrophages incubated with acetylated lipoproteins.

Mouse peritoneal macrophages accumulate large amounts of cholesteryl ester when incubated with human low-density lipoprotein that has been modified by chemical acetylation (acetyl-LDL). This accumulation is related to a high-affinity cell surface binding site that mediates the uptake of acetyl-LDL by adsorptive endocytosis and its delivery to lysosomes. The current studies demonstrate that the cholesteryl ester accumulation can be considered in terms of a two-compartment model: (a) the incoming cholesteryl esters of acetyl-LDL are hydrolyzed in lysosomes, and (b) the resultant free cholesterol is re-esterified in the cytosol where the newly formed esters are stored as lipid droplets. The following biochemical and morphologic evidence supports the hydrolysis-re-esterification mechanism: (a) Incubation of macrophages with acetyl-LDL markedly increased the rate of cholesteryl ester synthesis from [14C]oleate, and this was accompanied by an increase in the acyl-CoA:cholesteryl acyltransferase activity of cell-free extracts. (b) When macrophages were incubated with reconstituted acetyl-LDL in which the endogenous cholesterol was replaced with [3H]-cholesteryl linoleate, the [3H]cholesteryl linoleate was hydrolyzed, and at least one-half of the resultant [3H]cholesterol was re-esterified to form [3H]cholesteryl oleate, which accumulated within the cell. The lysosomal enzyme inhibitor chloroquine inhibited the hydrolysis of the [3H]cholesteryl linoleate, thus preventing the formation of [3H]cholesteryl oleate and leading to the accumulation of unhydrolyzed [3H]cholesteryl linoleate within the cells. (c) In the electron microscope, macrophages incubated with acetyl-LDL had numerous cytoplasmic lipid droplets that were not surrounded by a limiting membrane. The time course of droplet accumulation was similar to the time course of cholesteryl ester accumulation as measured biochemically. (d) When acetyl-LDL was removed from the incubation medium, biochemical and morphological studies showed that cytoplasmic cholesteryl esters were rapidly hydrolyzed and that the resultant free cholesterol was excreted from the cell.


Isolation of human platelet plasma membranes with polylysine beads.

Human platelet plasma membranes were isolated with polylysine beads according to the technique developed by Jacobson and Branton (1977, Science [Wash. D. C.] 195:302--304). Lactoperoxidase-catalyzed surface iodination revealed that ninefold greater 125I specific activity was associated with the membranes isolated on beads than with whole platelets. Enrichment in the bead membrane preparation of the activities of membrane marker enzymes, bis(p-nitrophenyl)phosphate phosphodiesterase and Na,K-ATPase, was 8.0 and 4.4, respectively. Contamination with enzymes of other organelles, cytochrome oxidase and beta-glucuronidase, was relatively low as compared with membranes isolated by sucrose gradient centrifugation. Analysis by SDS polyacrylamide gel electrophoresis showed that a full complement of surface glycoproteins was present on the membranes isolated with polylysine beads. The polylysine bead technique is a rapid, reproducible and efficient method for the preparation of relatively pure platelet plasma membranes.


Hormonally regulated phosphoprotein of turkey erythrocytes: localization to plasma membrane.

The catecholamine-stimulated cotransport of sodium and potassium ions across the plasma membrane of the turkey erythrocyte was previously found to be associated with increased 32P incorporation into a high molecular weight protein. To determine the subcellular localization of this phosphorylated protein, which we have termed goblin, a new method has been developed for isolation of pure plasma membranes from turkey erythrocytes. With this method, it has been demonstrated that goblin is located in the plasma membrane. Goblin is not extracted by solutions of low or high ionic strength but is partially extracted by nonionic detergents, indicating that it is not a component of turkey erythrocyte spectrin and suggesting that it may be an intrinsic protein of the plasma membrane. The data are compatible with a possible role for goblin in the hormonal control of ion movements across the plasma membrane.


Elasmobranch rectal gland cell: autoradiographic localization of [3H]ouabain-sensitive Na, K-ATPase in rectal gland of dogfish, Squalus acanthias.

Specific binding of radiolabeled inhibitor was employed to localize the Na-pump sites (Na,K-ATPase) in rectal gland epithelium, a NaCl-secreting osmoregulatory tissue which is particularly rich in pump sites. Slices of gland tissue from spiny dogfish were incubated in suitable [3H]ouabain-containing media and then prepared for Na,K-ATPase assay, measurement of radiolabel binding, or quantitative freeze-dry autoradiography at the light microscope level. Gross freezing or drying artifacts were excluded by comparison with additional aldehyde-fixed slices. Characterization experiments demonstrated high-affinity binding which correlated with Na,K-ATPase inhibition and half-saturated at approximately 5 microM [3H]ouabain. At this concentration, the normal half-loading time was approximately 1 h and low-affinity binding to nonspecific sites was negligible. Autoradiographs from both 1- and 4-h incubated slices showed approximately 85% of the bound [3H]ouabain to be localized within a 1-micrometer wide boundary region where the highly infolded basal-lateral cell membrane are closest to the mitochondria. These results establish that most of the enormous Na,K-ATPase activity associated with rectal gland epithelium is in the basal-lateral cell membrane facing interstitial fluid and not in the luminal membrane facing secreted fluid. Moreover, distribution along the basal-lateral membrane appears to be nonuniform with a higher density of enzyme sites close to mitochondria.


Restriction of patching of bound concanavalin A after incorporation of arachidonic acid into the plasma membrane of virally transformed fibroblasts.

Topographical distribution of concanavalin A binding sites (CABS) was studied in two lines of virally transformed fibroblasts as a function of fatty acid composition. Fatty acid composition was manipulated by incubating cells in fatty acid, ATP, CoA, and delipidated fetal calf serum (FCS). VLM cells grown in medium containing 5% FCS have a clustered CABS distribution. Plasma membrane vesicles (PMVs) derived from these cells have an arachidonate content of 1.7%. Elevation of PMV arachidonate to 15.8% results in a marked restriction of CABS patching, while elevation to 6.8% is associated with intermediate restriction of patching. Restriction of patching is associated with increased microviscosity. CABS of Rous sarcoma virus-transformed chicken embryo fibroblasts (RSV-CEF) are also responsive to arachidonate enrichment medium. Whereas untreated cells have a clustered CABS distribution, cells incubated for 24 h in arachidonate enrichment medium have predominantly a dispersed CABS distribution. In both VLM cells and RSV-CEF, ATP, CoA, and delipidated FCS alone have no effect upon CABS mobility. Inhibition of CABS patching is also observed when aspirin is included in the arachidonate enrichment medium but not when the cells are incubated in prostaglandins, thus suggesting that the restriction of CABS mobility is not mediated by prostaglandins. Other fatty acids (palmitate, oleate, nonadecanoate) failed to restrict CABS movement. The inhibition of CABS mobility is independent of cell shape change.


Cell cycle dependence of transformation expression in mouse cells transformed by a thermosensitive mutant (Ts-121) of polyoma virus.

Change in division capability as a phenotypic expression of cellular transformation was investigated by using one of the temperature-sensitive (ts) mutants of the polyoma virus-transformed cell line, the 121-6-5 cells of BALB/3T3. When contact -inhibited cells were treated with hyaluronidase at 39 degrees C, a single round of cell division was induced after which cell growth was inhibited by cell density. However, if the cells were incubated at 35 degrees C, after the enzyme treatment, density-inhibition block disappeared and the cells entered a second division. This indicates that the release of cells from density-inhibition depends on the low temperature incubation. The ability of cells to complete a second division was examined by shifting the cells from 39 degrees C to 35 degrees C during different phases of the first division cycle after the enzyme-treatment. A 6-hour incubation of S phase cells at 35 degrees C resulted in a second cycle of division, while the 24-hour incubation of G1 cells at 35 degrees C did not induce a second round of division. These results suggest that expression of the transformed phenotype in 121-6-5 cells is clearly dependent upon both the temperature and the phase of the division cycle.


Hemicyst formation stimulated by cyclic AMP in dog kidney cell line MDCK.

Certain epithelial cell lines have morphologic, physiologic, biochemical and pharmacologic characteristics of transporting epithelia from intact organs. In this paper we show that dibutyryl cyclic AMP, 5' AMP, adenosine and cyclic AMP phosphodiesterase inhibitors stimulate hemicyst formation by the dog kidney cell line MDCK. It is suggested that this effect is explained by elevation of intracellular cyclic AMP levels by means of an exogenous non-metabolizable source of cyclic AMP, phosphodiesterase inhibition or adenyl cyclase stimulation. Since hemicyst formation is in part due to transepithelial fluid transport, these findings raise the possibility that this fraction might be modulated by cAMP in an established cell line. We believe that cultured epithelial cells may provide an exploitable model system to investigate at the cellular and subcellular levels, the mechanism by which cyclic AMP modifies water and solute movements across epithelia.


Regulation of the proliferative response in Rous sarcoma virus transformed chicken embryo fibroblasts by serum and multiplication-stimulating activity (MSA).

A temperature sensitive mutant of Rous sarcoma virus (tsNY68) was used to obtain cultures of quiescent virus-infected chicken embryo fibroblasts arrested by serum starvation at the non-permissive temperature. Upon shift to the permissive temperature, these cells enter the replicative cell cycle as evidenced by increases in 2-deoxyglucose uptake, 3H-thymidine incorporation and percent labeled nuclei. These changes occur in the absence of serum and the cells become morphologically transformed within eight to ten hours after the temperature shift. Entry into the S phase temporally resembles that of normal quiescent fibroblasts stimulated with serum. This experimental system was used to examine the proliferative response of transformed cells to serum and purified multiplication-stimulating activity (MSA) during the transition from the resting to the growing state. Data are presented which show that the presence of serum in the medium enhances the proliferative response of quiescent infected cells shifted to the permissive temperature over those shifted in the absence of serum. In contrast, the presence of MSA has no additional effect on the response exhibited by infected cells shifted to the permissive temperature in serum-free medium. Labeled MSA binding experiments show that this lack of response is not due to a loss of MSA receptors on the cell surface since transformed cells are still capable of binding MSA at the same level as normal cells. The results are consistent with the hypothesis that the set of biochemical events initiated by MSA in normal cells are turned on in infected cells shifted to the permissive temperature by the activation of the src gene product.


Selective high metabolic lability of uridine, guanosine and cytosine triphosphates in response to glucose deprivation and refeeding of untransformed and polyoma virus-transformed hamster fibroblasts.

Sugar deprivation of hamster fibroblasts (NIL) affected the steady state levels (pool sizes) of cellular acid soluble nucleotides in the folloing fashion: the pools of UTP, GTP and CTP decreased to a much greater extent than the cellular ATP pools, with the UTP pools undergoing the most dramatic reduction. Sugar deprivation of polyoma-transformed NIL cells (PyNIL) yielded even sharper decreases in the nucleoside triphosphate pools with relative changes similar to those of the untransformed cells. Inhibition of protein synthesis by cycloheximide, initiated at the onset of (and continued during) sugar deprivation, prevented the reduction in pool sizes and yielded values slightly higher than those observed for pool sizes in cells cultured in sugar-supplemented medium. Refeeding glucose to sugar-depleted hamster fibroblasts led to rapid increases (within 1 hour) in the UTP and CTP pools to levels well above the pool sizes observed in cells which were continuously cultured (16 hours) in sugar supplemented medium. Feeding NIL or PyNIL cells with fructose instead of glucose as the only hexose source did not appreciably affect any of the ribonucleoside triphosphate pool sizes. Measurements of hexose uptake by NIL and PyNIL cells under a variety of conditions suggest that hexose transport is not regulated by the total cellular pools of ATP or any of the other ribonucleoside triphosphates.


Substantial rise of plasma beta-endorphin levels after insulin-induced hypoglycemia in human subjects.

To elucidate whether insulin-induced hypoglycemia enhances the release of beta-endorphin in man, plasma extracts obtained from healthy subjects and patients with Graves' disease before and 45 min after insulin injection were subjected to gel chromatography, and the fractions obtained were measured by RIA for beta-endorphin. In four healthy subjects, basal plasma beta-endorphin levels were less than 3 to 3.1 pg/ml, and the levels rose substantially to 47.5 +/- 12.4 pg/ml (mean +/- SE) 45 min after insulin injection. Basal plasma beta-endorphin levels in three hyperthyroid patinets (less than 3 to 3.8 pg/ml) did not seem to be different from those in healthy subjects; however, the rise after insulin injection tended to be higher in cases of hyperthyroidism, with a peak value of 68.5 +/- 9.7 pg/ml. Plasma beta-lipotropin and ACTH levels also rose in parallel with beta-endorphin in response to insulin-induced hypoglycemia in both healthy subjects and hyperthyroid patients. It would thus appear that beta-endorphin, like ACTH or beta-lipotropin, is released in human subjects by hypoglycemic stress.


Entamoeba histolytica: efficacy of microscopic, cultural, and serological techniques for laboratory diagnosis.

Of 110 subjects with clinical evidence of amebiasis, 15 (14%) were shown to be infected with Entamoeba histolytica. Microscopic examination of stool specimens rendered a diagnosis in all eight cases of localized intestinal infection, but in only one of seven patients with invasive amebiasis. Culture was concomitantly diagnostic in six patients intestinal amebiasis and in one patient with extraintestinal infection. Assay for antibody to E. histolytica by counterimmunoelectrophoresis and indirect hemagglutination were each 100% effective in all cases of invasive amebiasis and in diagnosing two of eight patients with intestinal infection. Stool specimens of 15 patients revealing intestinal parasites other than E. histolytica failed to demonstrate cultural or serological evidence of amebiasis. Low levels of antibody were observed in the indirect hemagglutination assay in four patients with disease other than amebiasis and in three control sera positive for rheumatoid factor. By counterimmunoelectrophoresis, reactive sera were only encountered among those derived from patients with amebiasis. Six of seven patients with hepatic amebiasis may have gone undiagnosed if not for serology.


Factors involved in enzyme-linked immunoassay of viruses and evaluation of the method for identification of enteroviruses.

A quantitative enzyme-linked immunosorbent assay was used for identification of selected enteroviruses: poliovirus type 1, echovirus type 6, coxsackievirus A type 9, and coxsackievirus B types 1 through 6. Partially purified viral antigens or virus-specific antibodies were adsorbed to polystyrene spectrophotometer cuvettes, which permitted the assays to be reported and compared in terms of enzyme units specifically reacting. Both the adsorbed antigen and the adsorbed antibody methods were approximately equal in terms of sensitivity and specificity of reaction. By use [14C]leucine-labeled enteroviruses, the amount of virus that bound to the plastics used was shown to be dependent on the purity of the virus preparation used, but it was higher than the amount that was bound by plastics coated with viral antibody. Diluents which contained 0.15% (vol/vol) Tween 20 and 2.0% (wt/vol) bovine serum albumin in phosphate-buffered saline, pH 7.2, were found to be the most effective in inhibiting nonspecific adsorption of immunoreagents. However, the presence of these inhibitors in phosphate-buffered  saline solutions also caused desorption of virus or viral antibody during immunoassays; the amount of virus desorption varied with the type of preparation used, and antibody desorption was dependent on the concentration of antibody initially used for adsorption. For specific identification of a given enterovirus type by the enzyme-linked immunosorbent assay method used, approximately 10(5) plaque-forming units of virus per assay tube were required.


Counterimmunoelectroosmophoresis for detection of neonatal calf diarrhea coronavirus: methodology and comparison with electron microscopy.

A counterimmunoelectroosmophoresis (CIE) technique is described for the detection of calf diarrhea coronavirus antigens in intestinal contents. The antibody reagent was prepared in rabbits against the Nebraska calf diarrhea coronavirus adapted to Vero cells and purified by density gradient centrifugation. The method was applied to intestinal contents of diarrheic and normal calves and compared with electron microscopy (EM). Calf coronavirus antigens were detected in intestinal contents of 44% (21/48) of the diarrheic calves and 24% (4/17) of the normal calves. Two precipitin lines could be observed in the majority of the positive samples. When compared with EM, CIE detected more positive animals. In only two cases (2/20) CIE was negative despite the visualization of coronavirus particles by EM.


Cytological diagnosis of virus-infected cells in Papanicolaou smears and its application in clinical practice.

The cytopathic changes of herpes simplex virus, varicella-zoster virus, the human polyomaviruses, and the trachoma agent can be recognised in smears prepared from a wide variety of specimens. The morphology of virus-infected cells is described, and the clinical value of these observations is discussed. Cytological diagnosis offers a rapid and convenient method of detecting infection with these viruses which can be confirmed by conventional virological method while the patient is still in the acute stages of the disease. Confirmation can also be made retrospectively by reprocessing cells, identified in the Papanicolaou smear, for electron microscopy. Screening for virus-infected cells in cytological smears is a technique that can be developed in any pathology laboratory prepared to provide a comprehensive cytology service, and it is proving to be a useful tool in clinical diagnosis and applied research.


Carcinoma in situ of the male breast.

Two cases of carcinoma in situ of the male breast are described: in one patient it arose as a complication of gynecomastia; in the other, it occurred 'de novo' and proceeded to infiltration with widespread metastases. We reviewed 233 cases diagnosed clinically and histopathologically as gynecomastia to see if we could discover other instances of malignant transformation but none was found. Thirty-two cases of infiltrating male breast cancer were also examined. In 11 there was associated intraduct change. In only one of the 32 cases was there evidence of associated microscopic gynecomastia.


Winter vomiting disease caused by calicivirus.

The clinical, epidemiological, and virological features of an outbreak of winter vomiting disease among London schoolchildren are described. Evidence is presented to support the view that this epidemic was caused by a human calicivirus, a virus not previously shown to be associated with this disease in man.


An immunohistochemical study of distribution of carcinoembryonic antigen in epithelial tumours of the ovary.

An immunohistochemical study of the tissue CEA content of 82 epithelial neoplasms of the ovary has shown that mucinous tumours contain more of this substance than do their serous counterparts; otherwise a knowledge of tissue CEA content appears to be of little value in the differential histological diagnosis of this group of neoplasms. Among mucinous tumours there is only a partial correspondence between their degree of malignancy, as assessed histologically, and their content of CEA. It is postulated that immunohistological study of tissue CEA may add a degree of finesse to morphological analysis of these neoplasms and thus allow for a more precise grading of their degree of malignancy.


Factors involved in skin carcinogenesis.

A personal account of skin carcinogenesis is given based on forty years of investigation of normal and pathologic anatomy of the human skin. Symbiosis of acral portions of adnexa and of melanocytes with epidermal keratinocytes is stressed, and perversion of symbiosis to parasitism in tumor formation is discussed. The role of the basement membrane as a combined effort of, and filter between, ectoderm and mesoderm is stressed, and the nature of basal cell epithelioma as the least differentiated member of the tribe of fibroepithelial adnexal tumors is outlined. Experimental data supporting the promoting role of specific mesodermal stroma in basalioma formation and maintenance are presented.


Immunology of human warts.

Rapid advances have occurred in the characterization of human papilloma virus (HPV) types applying the new advanced techniques of restriction endonuclease analysis and molecular hybridization to human wart virus. Human papilloma virus can no longer be viewed as a single, homogeneous virus producing all varieties of clinical warts. At least three antigenically heterogeneous HPV types have been associated with common and plantar warts. Two additional HPV types have been found in patients with epidermodysplasia verruciformis. Condylomata acuminata and laryngeal papillomas contain viruses which are also distinct from the preceding viruses and may represent additional HPV types. This antigenic heterogeneity of HPV has important implications concerning the immunology of human warts which have not been taken into account in most previously published studies. Both antibody and cell-mediated responses may be seen in patients with active warts, but many patients with warts have no demonstrable immune reactions. The role of immunity in wart regression remains poorly understood. Nevertheless, the increased frequency of warts in patients receiving immunosuppressive drugs and with immune deficiency states and the immunologic alterations which occur in patients with regressing or cured warts compared to patients with active warts, particularly the increased frequency of cell-mediated responses and antibodies specific for viral antigens, support a possible role for immunity in the resolution of warts. The evidence to date, however, does not prove that immune mechanisms are directly responsible for the elimination of warts.


Tortuous vertebrobasilar arteries causing cranial nerve syndromes: screening by computed tomography.

Considerable concern with cranial nerve syndromes has often required detailed information of the relationship between the vertebrobasilar system and the brainstem. The obvious invasiveness of conventional vertebral angiography poses the question of whether computed tomography (CT) might serve as a satisfactory technique or even as a sufficient diagnostic method. During a 12 month period, 12 of 250 patients with cranial nerve syndromes were diagnosed by CT as having vertebrobasilar ectasia. This communication correlates the clinical symptomatology with angiography and CT and presents evidence that CT alone can prove satisfactory.


Tumors of the glomus jugulare complex (chemodectomas) demonstrated by cranial computed tomography.

The appearance of six glomus tumors (four glomus jugulotympanicum and two vagal body tumors) is demonstrated in four patients. In one case, glomus tumor tissue is visualized by computed tomography (CT) inside the tympanic cavity. The importance of the use of different window settings is stressed. The value of CT in comparison to arteriography and polytomography is briefly discussed. Computed tomography is recommended in the evaluation of the course of a glomus tumor and in radiation therapy treatment planning of these tumors.


Determination of mycophenolic acid, penicillic acid, patulin, sterigmatocystin, and aflatoxins in cheese.

A method has been developed for detection of aflatoxins, mycophenolic acid, patulin, penicillic acid, and sterigmatocystin in cheese. It is based on selective extraction with a mixture of equal volumes of 5% sodium chloride, methanol, and aceton, precipitation of caseins at -25 C, defatting with hexane, and removal of extraneous matter by transfer of mycotoxins to chloroform and ethyl acetate. The extract is purified further by column chromatography. Mycotoxins are quantitated on thin layer chromatograms by fluorescence comparisons. Mycophenolic acid, patulin, and penicillic acid are visualized with diethylamine. The limits of detection in cheese are about 20 micrograms/kg for mycophenolic acid, patulin, and sterigmatocystin, 30 microgram/kg for pencillic acid, and 1 microgram/kg for aflatoxins B1 and M1.


Enzyme immunoassay for measuring lipoprotein lipase activator in milk.

A method for determining the relative amount of lipoprotein lipase activator in milk was developed. The activator was measured in arbitrary units which were based on a standard curve for high density lipoprotein. Activator varied between cows not only in whole milk but also in skim milk and milk serum. Most of the activator was in the skim milk, and the amount of activator in milk serum varied between 32 and 91% of that in skim milk. In seven of eight cows, free fatty acids of milk increased with increasing units of activator.


The effect of epinephrine on pulpal microcirculation.

The effect of epinephrine (Epi) on the microcirculation of the pulp and its neuropharmacological mechanism has been established, as well as the existence of alpha adrenergic receptors in the blood vessels of the pulp. In addition, our results showed that local injections of Epi at doses greater than 10(-8) M produced an extreme drop in intrapulpal pressure (IPP). This effect was not obtained when Epi was injected intravenously.


Collagenolytic activity of crevicular fluid  and of adjacent gingival tissue.

The fluid in and gingival tissue lining periodontal pockets were collected from male patients undergoing periodontal therapy. The collagenolytic activity of the crevicular fluid, and the ability of the gingiva in culture to degrade (a) an exogenous collagen substrate, and (b) endogenous collagen newly synthesized and labeled with H3-hydroxyproline, were related to the severity of gingival inflammation. Although inflammation appeared to have only a slight effect on gingival collagenolytic activity and on the turnover of collagen newly synthesized in culture, a marked effect was observed on the collagenase activity in the crevicular fluid. This study suggests that the collagen destructive activity of the periodontal lesion can be assessed by monitoring crevicular fluid collagenolytic activity.


Insomnia in the elderly: treatment with flurazepam hydrochloride.

Under sleep-laboratory control, the efficacy of flurazepam hydrochloride (15 mg) was evaluated in 6 women (age range, 67-82 years) with objectively verified insomnia. A 15-night, single-blind, crossover procedure was followed. Sleep records obtained during 3 placebo-baseline nights, 7 consecutive flurazepam nights, and 3 placebo-withdrawal nights were evaluated by means of electroencephalographic, electro-oculographic, and electromyographic criteria. A statistically significant reduction in sleep latency and total awake time and a corresponding increase in total sleep time (P less than 0.05) were demonstrated during the active drug period. No evidence of diminishing effectiveness was observed during the 7 days of drug administration. For the rapid-eye-movement (REM) stage, a significant decrease (P less than 0.05) in mean REM percent was noted during the drug period despite an increase in mean absolute REM time. No REM rebound occurred upon drug withdrawal. There were no significant changes in mean percentages for stages 3 and 4 during the drug period and the withdrawal period. Adverse reactions were rare (chiefly some daytime drowsiness in 2 subjects).


Prolactin receptors: a comparison between chloramine-T and lactoperoxidase iodination.

The binding properties of chloramine-T iodinated oPRL (using a modified iodination procedure) to prolactin receptors of female rat liver membrane particles were compared with those of lactoperoxidase iodinated oPRL. The results indicated that both iodination methods provided 125I-oPRLs which were suitable for receptor binding studies. Our results suggested that chloramine-T 125I-oPRL was even better than lactoperoxidase 125I-oPRL in terms of lower nonspecific binding. The chloramine-T iodinated oPRL was used to study the prolactin receptors in rat ovaries and DMBA induced rat mammary tumors. The results showed that the amount of prolactin receptors in rat ovaries was related to the plasma level of prolactin as it had been reported in liver by other investigators. The study of prolactin receptors in rat mammary tumors indicated that the prolactin receptor content of hormone dependent mammary tumors was much higher than that of hormone independent mammary tumors.


Serum somatomedin and insulin levels in tumor hypoglycemia.

Serum concentrations of somatomedin and immunoreactive insulin were measured during the hypoglycemic phase of 3 patients with tumor hypoglycemia. Normal amounts of somatomedin were detected in their fasting sera, but they may have been inappropriate (or associated with enhanced insulin-like activity) considering the degree of hypoglycemia. Fasting serum insulin levels were consistently depressed, and in two of the cases remained low even after an oral glucose load. Nevertheless, the blood glucose concentrations of these two patients fell to hypoglycemic levels again by 3 hours; the mechanism of this reactive hypoglycemia remains unclear.


Thyrotropin receptor-adenylate cyclase system in plasma membranes from normal and diseased human thyroid glands.

Thyrotropin binding characteristics and adenylate cyclase (AC) activity of thyroid plasma membranes were studied in 52 tissues from normal and diseased human thyroids. Data from normal glands, Graves' goiters, non toxic multinodular goiters and nodular and perinodular tissue of toxic nodular goiters show the same basal, TSH- and NaF- stimulated adenylate cyclase activities (no. = 45; 34.1 +/- 3.2 (m +/- SE), 378 +/- 43, 298 +/- 48 pmol cAMP x min-1 x mg membrane protein-1), the same stimulability of AC by TSH (11.3 +/- 1.4--fold over basal level) and by NaF (8.1 +/- 1.8-fold), the same apparent TSH binding equilibrium constants (5.6 +/- 0.7 and 406 +/- 57 nM) and the same TSH binding site concentrations (2.2 +/- 0.4, 27.8 +/- 5.9 pmol x mg membrane protein-1). Alterations of the TSH receptor and of the AC were detected in membranes from tumoral and metastatic lymph node tissues from thyroid papillary carcinoma and in the thyroid tissue from post-radioiodide therapy thyroiditis. These observations suggest that: (i) hyperthyroidism in Graves' disease or toxic nodular goiter does not result in and is not a consequence of an alteration in the TSH receptor-adenylate cyclase system; (ii) there is no evidence supporting a relationship between the studied membrane properties and clinical or histological status; (iii) membrane abnormalities detected in thyroid carcinoma vary widely; (iv) studies of these membrane alterations might be of interest in the therapeutic management of thyroid carcinoma and may lead to a better understanding of the receptor-adenylate system.


The adenylate cyclase-cyclic AMP-phosphodiesterase system in pathological human thyroid.

The adenylate cyclase-cyclic AMP-phosphodiesterase system of human thyroid tissues adjacent to cold nodules (control), two follicular adenomas, one hyperplastic thyroid and one hyperfunctioning follicular carcinoma have been compared. In the hyperfunctional follicular carcinoma the basal adenylate cyclase is much higher than in control tissue, carcinoma adenylate cyclase does not respond to TSH and prostaglandin E1, whereas it responds normally to fluoride. In the hyperplastic, but hypofunctional thyroid the basal adenylate cyclase is higher than in normal tissue whereas the response to TSH, PGE1, and fluoride is normal. No difference between the follicular adenomas and normal thyroid stimulated and unstimulated adenylate cyclase was observed. Furthermore in various thyroid tissues no changes in the level of cyclic AMP phosphodiesterase was found. Our data indicate a greater change in the synthesis rather than in degradation of cyclic AMP in the human pathological thyroids studied.


Failure of oral bromocriptine to affect hypergastrinemia in two patients with the Zollinger-Ellison syndrome.

Bromocriptine was administered to 2 subjects with gastrin-secreting tumors of the pancreas. The absorption of the drug was confirmed by a rise in growth hormone levels but no change in the elevated serum gastrin levels were observed. Bromocriptine does not appear to affect gastrin hypersecretion in the way that it influences the hypersecretion of pituitary hormones.


Lack of effect of bromocriptine on ACTH levels in patients with bilateral adrenalectomy for pituitary-dependent Cushing's syndrome.

Bromocriptine lowers plasma ACTH levels in patients with pituitary-dependent Cushing's syndrome. It seemed possible that the drug would also be effective in patients who had been adrenalectomised for the disease. The effect of 5.0 mg of bromocriptine on plasma ACTH and prolactin levels in 13 patients, bilaterally adrenalectomised for pituitary-dependent Cushing's syndrome, was therefore studied. In only one patient was a fall in plasma ACTH observed. This may be of doubtful significance since marked spontaneous fluctuation in plasma ACTH levels were found in the five patients tested. Bromocriptine lowered the plasma prolactin in all of the patients, including two with hyperprolactinaemia.


Evaluation of the operative treatment of syndactyly.

A review of the records of 61 patients with 176 surgically treated webs was completed to evaluate the results of the different operative techniques used to separate the fingers. The postoperative follow-up period averaged 14 years, with a range from 2 to 38 years. The patients were assessed in two groups: those with major associated anomalies and those in whom syndactyly was the principal anomaly. Recurrence of the webs and flexion and extension contractures occurred more often when split-thickness grafts were used. To obtain a satisfactory result, a second procedure was necessary in 59% of patients with major associated anomalies, and in 30% of the patients who had syndactyly as the principal abnormality. Two types of patients were found to require subsequent operations: children treated prior to 18 months of age and those with complex syndactyly.


Autoradiographic visualization of beta-adrenergic receptors in normal and denervated skeletal muscle.

Autoradiographic localization of beta-adrenergic receptors in rat skeletal muscle in vivo was achieved utilizing [125I]-iodohydroxybenzylpindolol, a potent beta-adrenergic blocker with high affinity and specificity for those receptors. In normal muscle the beta-adrenergic receptors were localized mainly to blood vessels, arterioles greater than venules, with much less concentration of grains over the fascicles of muscle fibers. One week after denervation there was an increase in binding both to blood vessels and muscle fibers, more so in soleus and gactrocnemius than in extensor digitorum longus. While these results parallel in vitro biochemical studies, they dictate caution when inferring cellular localization of beta-adrenergic receptors (and other molecules) solely on the basis of biochemical techniques applied to subcellular fractions of whole-organ homogenates.


Cytochemical bioassay and radioimmunoassay of ACTH in noise stressed rats.

Serum corticosterone and ACTH levels were measured in rats subjected to one and two 30 min intervals of noise (100 dB, 250--20,000 Hz). Both hormones were elevated immediately after noise exposure, dropped below pre-exposure levels after a 2 hr recovery interval and were again elevated with a second exposure. The ratio of immunoactive to bioactive ACTH was slightly depressed after one exposure and markedly depressed after two successive noise exposures (relative to controls) indicating that multiple exposure to auditory stimulation effects a proportionally greater output of bioactive ACTH.


Pathology of the endocrine pancreas.

An immunocytochemical analysis of 94 pancreatic endocrine tumors revealed that 73 tumors were multicellular. Significant amounts of somatostatin and human pancreatic polypeptide were found by radioimmunoassay in extracts of 19 and 17 tumors resp., in addition to the hormone causing the clinical syndrome. Numerous tumors contained ductular structures. In the surrounding pancreatic parenchyma a proliferation of small ducts and budding-off from the ductular epithelium of endocrine cells was often observed. These features are hallmarks of nesidioblastosis of the endocrine pancreas which is a hyperplasia. In multiple endocrine neoplasia I hyperplasia of the endocrine pancreas is combined with larger nodules, currently labeled tumors. On the basis of these findings it is conceivable that pancreatic endocrine tumors are not primarily neoplastic and autonomous but that they are rather of hyperplastic origin.


Comparison of immunofluorescence and radioimmunoassay for detecting IgM antibody in infants with the congenital rubella syndrome.

Immunofluorescence (IF) and radioimmunoassay (RIA) have been compared as methods for detecting IgM antibody in 124 infants with confirmed or suspected congenital rubella. IF was used to test sucrose density gradient fractions and RIA to test fractions and whole serum. When fractions were tested IF and RIA were equally specific and distinguished clearly between IgM and IgG, but RIA was the more sensitive method. The RIA titre in whole serum was always greater than in the peak IgM fraction and there was no evidence that testing the serum, rather than the fraction, could result in failure to detect IgM. With some sera RIA gave low titres which became negative after absorption with IgG-coated latex beads. The mechanism of this 'false positive' effect, which may have been due to IgM with anti-IgG activity, was not investigated, but if it can be removed by absorption it need not reduce the specificity of the test. During the first 6 months of life IgM antibody was detected by RIA in 30 out of 32 unfractionated sera and by IF in fractions from 28 of these. After the age of 6 months IgM was found progressively less frequently and the greater sensitivity of RIA became a more obvious advantage: 17 out of 60 specimens were positive by RIA and 11 of these were negative by IF. RIA testing of whole serum appears to be an economical, specific and sensitive method for detecting IgM antibody in congenital rubella, of particular value when the titre of antibody is low.


A blastogenic test for foot-and-mouth disease.

A blastogenic test to detect peripheral blood leukocytes specifically sensitized to foot-and-mouth disease virus antigen is described. The test is carried out in microtitre plates and optimum conditions were found by titration. These employed 7.5 x 10(5) cells/well and 20 complement fixing units of antigen. Peak [3H]thymidine incorporation was found to take place at 2-3 days.


Application of the enzyme linked immunosorbent assay to the detection and identification of foot-and-mouth disease viruses.

An indirect enzyme linked immunosorbent assay (ELISA) was applied to the detection and identification of foot-and-mouth disease (FMD) virus types. The test proved successful for the specific detection of virus from infected tissue culture, and from epithelial tissues from bovines suspected of having FMD. The ELISA compared favourably with the complement fixation (CF) test, being more sensitive and unaffected by anticomplementary factors.


Incidence of bluetongue virus precipitating antibodies in sera of some domestic animals in the Sudan.

To determine the presence and prevalence of bluetongue (BT) infection in a variety of domestic animal species in different geographical regions of the Sudan, a serological study using the agar gel precipitation technique was initiated. A total of 2142 serum samples were examined. Of the numbers tested approximately 28% of sheep, 11.2% of goats, 8% of cattle and 4.9% of camels were positive for group-specific antibodies to BT virus antigen, indicating previous exposure to BT infection. None of the samples tested from horses or donkeys were positive. The findings suggest that the disease is widely distributed in most parts of the Sudan where possible insect vectors prevail and may be endemic in sheep in Juba District, Equatoria Province, Southern Region. Goats appeared to have some degree of resistance to infection compared with sheep, and there seemed to be no significant differences in positive rates between farm and free-range cattle. It is concluded that BT infection may cause clinical disease in sheep, while it is probably subclinical or inapparent in goats, cattle and camels of the Sudan.


Possible origin of the bluetongue epidemic in Cyprus, August 1977.

Possible origins of an epidemic of bluetongue in Cyprus in August 1977 have been analysed. First outbreaks occurred simultaneously in the south-east of the Famagusta district and on the north coast of the Kyrenia district respectively. Although the epidemic was due to type 4, which had been responsible for the previous outbreak in 1969, no evidence of persistance of virus could be found. Imports of domestic animals in the past year were not implicated since the imported cattle were introduced only to the southern part and not to the northern part of the island. Easterly, north-easterly and northerly winds during the period 11-14 August could have brought infected midges at a height of 0.5--1.5 km from Syria and Turkey, and such a movement would fit well the dates of the first outbreaks (20-25 August). Temperatures at a height of 1.5 km were 20-25 degrees C and at 0.5 km 30 35 degrees C, and with wind speeds 10-20 km h-1 the distance from Turkey and Syria would have been covered in 5-20 h. It follows that, in addition to surface winds, winds at all levels warm enough for flight should be taken into account when the possibility of disease spread by windborne midges is being assessed.


Inhibition of human monocyte-macrophage and lymphocyte cytotoxicity to herpes simplex-infected cells by glucan.

The effect of short term in vitro incubation of glucan--a reticuloendothelial system stimulator--on subsequent cytotoxicity of human monocyte-macrophages (MP) and lymphocytes (L) to Herpes simplex virus-infected cells in a 51Cr-release assay was analyzed. Particulate, cell-associated glucan irreversibly inhibited MP antibody-dependent cellular cytotoxicity (ADCC). In contrast, the inhibition of L-ADCC and L-natural killer cytotoxicity could be reversed by dissociation of glucan and cells utilizing serum gradient centrifugation, a process which did not remove the glucan. These experiments reveal further basic differences between MP and L-ADCC using the reagent glucan.


Immobilization of viral antigens on filter paper for a [125I]staphylococcal protein A immunoassay: a rapid and sensitive technique for detection of herpes simplex virus antigens and antiviral antibodies.

A new technique is described for the rapid detection and quantitation of herpes simplex virus (HSV) antigens and antiviral antibodies. It involves immobilization of HSV antigens on filter paper discs and subsequent analysis by 125I-labeled staphylococcal protein A (SPA) radioimmunoassay. A specially designed 96-well filtration device is employed which serves both as an incubation chamber and as a filtration manifold. It is rapid, simple, sensitive and specific, and requires only small volumes of antiserum and few target cells. The results may be readily and objectively quantitated. This technique permits the simultaneous assay of a large number of specimens in less than 1 h. Its sensitivity is considerably greater than that of other currently used immunologic techniques, and it is amenable to automation. These characteristics suggest that this [125I]SPA immunofiltration technique may be applicable to the rapid diagnosis of viral infections.


Incidence of infectious mononucleosis at the Universities of California and Hawaii.

The observed rates of heterophil-positive infectious mononucleosis at the University of California at Davis and the University of Hawaii at Manoa were 1,212 and 37 per 100,000 students per academic year, respectively. The data collected suggest that the extraordinarily low incidence at the University of Hawaii may be due to the following factors: (1) underutilization of the student health service by students with infectious mononucleosis; (2) low proportion of Epstein-Barr virus-seronegative students; (3) high proportion of Asian students who appear to be less likely to develop heterophil-positive infectious mononucleosis; and (4) possible low efficiency in the transmission of primary Epstein-Barr virus infections.


Specific cell-mediated immunity in children with congenital and neonatal cytomegalovirus infection and their mothers.

Cell-mediated immunity (CMI) to cytomegalovirus (CMV) and herpes simplex virus type 1 (HSV-1) was examined in 35 mothers and 30 of their offspring with congenital or neonatal CMV infection by means of the lymphocyte transformation assay. Eleven offspring did not respond to CMV antigen, and 15 of the 19 positive children displayed lower responses than those of normal immune adults. Productive infection in the younger children at the time of assay and the presence of disease correlated strongly with the absence of responses. The mothers as a group also demonstrated impaired CMI to CMV while reacting normally to HSV-1 antigen. Neither time after transmission of infection nor viral excretion was significantly associated with impaired CMI, although a trend toward diminished responses was evident among women who were shedding virus. Mitogen stimulation was normal in all test subjects. These findings imply that deficient specific CMI may play a role in the genesis of persistent CMV infection and fetal pathology.


Impaired cellular immunity to cytomegalovirus in congenitally infected children and their mothers.

Cell-mediated immunity to cytomegalovirus (CMV) was determined in congenitally infected children and their mothers by use of assays for CMV-specific lymphocyte blastogenesis and interferon production. Six viruric children responded poorly in both assays. Two older nonviruric children responded in the blastogenesis assay, and lymphocytes from one of them produced interferon. Mothers of older children usually responded in the blastogenesis assay, but only one of them produced interferon. Mothers whose infected infants were younger than nine months of age responded poorly in both assays, while control seropositive postpartum women generally responded normally. The cell-mediated immune defects detected in this study may play a role in the pathogenesis of congenital CMV infection.


A comparative study of hepatitis B viral markers in the family members of Asian and non-Asian patients with hepatitis B surface antigen-positive hepatocellular carcinoma and with chronic hepatitis B infection.

Serologic tests for evidence of hepatitis B virus (HBV) infection were performed on family members of Asian and non-Asian patients with either hepatitis B surface antigen (HBsAg)-positive hepatocellular carcinoma or chronic HBV infection. Asian family members had a significant increase of HBsAg (34% higher) and of antibody to HBsAg or of antibody to hepatitis B core antigen (50% higher) when they were compared with non-Asian family members. In the Asian group, viral markers were detected more frequently in blood relatives than in nonblood relatives of the index cases. Within this group, birthplace did not influence the frequency of antigenemia, since HBsAg was positive in 55 (44%) of 125 Asians born in Asia and in 36 (38%) of the 94 Asians who were born in the United States. Also, HBsAg positivity frequently was seen in offspring from HBsAg-positive carrier mothers as well as from HBsAg-positive carrier fathers whose spouses were either HBsAg-negative or who had antibody. The e antigen was found more often in individuals 30 years of age or younger than in older individuals. This study indicates that intrafamilial spread of HBsAg in Asian families plays an important role in the perpetuation of HBV infection and in the eventual development of chronic liver disease in this ethnic group.


Ocular infection with herpes simplex virus type 1: prevention of acute herpetic encephalitis by systemic administration of virus-specific antibody.

The effects of virus-specific antibody on the pathogenesis of infection due to herpes simplex virus type 1 (HSV-1) following corneal inoculation of young adult mice were studied. HSV-1 was inoculated onto the corneal surface immediately after trephination with a capillary pipette. After inoculation, virus spread to the trigeminal ganglion and brain within two days and caused acute herpetic encephalitis, which killed infected animals eight to 10 days after infection. Rabbit hyperimmune antisera to HSV-1 were prepared, diluted to contain antibody at a titer of 1:150, and administered intraperitoneally to mice 8 hr after corneal infection. Administration of antisera did not interfere with the spread of HSV-1 from the site of infection to the trigeminal ganglion and brain but did reduce the multiplication of virus within the central nervous system. Reduction in viral replication resulted in complete recovery of the animals that were given antibody to HSV-1. however, the animals were not protected if they were irradiated with 390 rad 24 hr prior to administration of antibody. This observation suggested that antibody-mediated protection was not the result of in vivo neutralization of virus but instead required the presence of antibody as well as one or more radiation-sensitive components.


Lethal effect of complement and lysozyme on polymyxin-treated, serum-resistant gram-negative bacilli.

When genetically serum-resistant Escherichia coli, Klebsiella pneumoniae, and Citrobacter freundii, but not Pseudomonas aeruginosa or Proteus mirabilis, were exposed to polymyxin B, they became susceptible to the bactericidal action of normal human and rabbit sera. In constrast, beta-lactam and aminoglycoside antibiotics did not render any serum-resistant bacteria serum-sensitive. Synergy between polymyxin B and the serum bactericidal system could be demonstrated by the addition of polymyxin B to bacteria in vitro, as well as to bacilli in serum from rabbits injected with the antibiotic. Polymyxin B-treated bacteria were killed by normal, lysozyme-depleted, C2-deficient, and hypogammaglobulinemic sera, but not by heated or C6-deficient sera. These findings indicate that polymyxin B-treated bacteria can be killed via the alternative complement pathway. However, C3 and C3b were detected on the surface of serum-resistant E. coli, regardless of whether the bacteria had been treated with polymyxin B. This observation suggests that a change in susceptibility to the alternative complement pathway was not the only explanation for the acquired serum sensitivity. Polymyxin B may also affect a step in the complement sequence beyond the activation of C3, a step that is apparently blocked in serum-resistant gram-negative bacteria.


Indirect immunofluorescence test for detection of IgM antibodies to cytomegalovirus.

A technique for the detection of IgM antibodies to cytomegalovirus (CMV) by immunofluorescence was developed. In order to prevent interference by rheumatoid factor in the sera, IgG was removed by prior immunoabsorption with antiserum to gamma Fc. Sera from 63 patients with a rise in titer of antibody to CMV, indicated by complement fixation, were IgM-positive, but yielded negative results on the Paul-Bunnell-Davidsohn test for infectious mononucleosis. Convalescent-phase serum samples from 20 patients with a seroconversion to herpes simplex virus and from 20 patients with a seroconversion to varicella-zoster virus also had no IgM antibodies to CMV. Sera from six of 10 patients with infectious mononucleosis and two of 100 normal blood donors were positive for IgM antibodies to CMV. In 38 of 63 patients, the diagnosis of CMV infection could be made several weeks earlier by the immunofluorescence test than by the complement-fixation test. IgM antibodies to CMV persisted for more than two months after onset of symptoms of the infection.


Antibody to varicella-zoster virus-induced membrane antigen: immunoperoxidase assay with air-dried target cells.

A technique using indirect immunoperoxidase antibody to membrane antigen (IPAMA) was developed for detection of IgG antibody to varicella-zoster virus (VZV). The IPAMA technique utilizes glass slides with air-dried VZV-infected cells, which can be stored at -70 C and used for several months without loss of sensitivity. Antibody titers measured by the IPAMA technique were comparable to those measured by the technique using indirect fluorescent antibody to membrane antigen (IFAMA) for sera obtained from 63 medical students as well as sera from three patients with chicken pox and nine with herpes-zoster infection, and the sensitivity of the IPAMA was equal to that of the IFAMA technique. No cross-reactivity with antibodies to other herpesviruses was observed.


Malignant pleomorphic fibrous histiocytoma of the larynx. (Further observations).

An exceptional case of pleomorphic malignant fibrous histiocytoma of the larynx occurring in a 68-year-old male patient is reported. A significant histological documentation is given. Problems connected with histogenesis, treatment and prognosis are dealt with. Stress is laid on the need to establish differential diagnosis from other neoplasms, in particular liposarcoma and spindle-cell carcinoma.


Granular cell myoblastoma in the parotid gland.

Granular cell myoblastomas develop most commonly in the head and neck region, but their occurrence in the salivary glands has been reported in only one case, in the submaxillary gland. The authors report a case of granular cell myoblastoma in a previously undescribed localization, the parotid gland.


Modern trends in surgical treatment of trigeminal neuralgia.

From 1955 to July 1978, 560 patients suffering from trigeminal neuralgia, who had not responded to medical treatment underwent various alternative procedures. Considering some of these to be out of date, some as showing too high a number of relapses and some as having potentially unjustified risks in an affection in itself not fatal, the authors report only the results observed in a series of 175 patients operated on by retrogasserian rhizotomy according to Frazier (1931), and the results of a series of 184 patients treated by controlled thermocoagulation according to Sweet and Wepsic (1974).


Effects of surgical stress and corticotrophin on the peripheral metabolism of thyroid hormones in rabbits.

The effect of surgical stress and ACTH injection on the peripheral monodeiodination of thyroxine (T4) was studied in the rabbit. These stimuli resulted in a switch from the peripheral formation of tri-iodothyronine (T3) to reverse T3 in normal rabbits and in rabbits whose thyroidal secretion was suppressed by administration of T4. This is analogous to the situation in man. These changes were not due to alterations in the serum binding capacity for thyroid hormones.


The glycolytic oscillator.

The glycolytic oscillator, mainly studied in yeast, is described with respect to its overall dynamic and biochemical properties and the kinetics of its master enzyme phosphofructokinase. Biochemical and kinetic analyses are complemented by analysis of mathematical models. In addition to the discussion of structure and function of the glycolytic oscillator under homogeneous spatial conditions, recent theoretical and biochemical experiments demonstrating spatial pattern formation are also discussed, followed by a presentation of physiological viewpoints.


A transmissible avian neoplasm. (Sarcoma of the common fowl) by Peyton Rous, M.D., Experimental Medicine for Sept. 1, 1910, vol. 12, pp.696-705.

In this paper is reported the first avian tumor that has proved transplantable to other individuals. It is a spindle-celled sarcoma of the hen, which thus far has been propagated into its fourth tumor generation. This was accomplished by the use of fowls of pure blood from the small, intimately related stock in which the growth occurred. Market-bought fowls of similar variety have shown themselves insusceptible, as have fowls of mixed breed, pigeons and guinea-pigs. The percentage of successful transplantations has been small, but in the individuals developing a tumor its growth has been fairly rapid. Young chickens are more susceptible than adults. The reinoculation of negative fowls has never resulted in a growth. Throughout, the sarcoma has remained true to type. It is infiltrative and destructive. Metastasis has been observed once (to the heart). Experiments to determine whether the growth may be transmitted by cell-fragments have not yet been made. Repeated bacteriological examinations have yielded negative results. In its general behavior, so far as tested, this avian tumor closely resembles the typical mammalian neoplasms that are transplantable.


Absence of allogeneic restriction in human T-cell-mediated cytotoxicity to Epstein-Barr virus-infected target cells. Demonstration of an HLA-linked control at the effector level.

Peripheral T lymphocytes from patients with infectious mononucleosis (IM) are sensitized in vivo against the Epstein-Barr virus (EBV). The expression of HLA-A, B, or C molecules at the target cell surface is necessary for the cytotoxic reaction because (a) EBV-positive Daudi cells lacking HLA-A, B, and C determinants are resistant to anti-EBV T-cell lysis, (b) cytolysis of EBV-positive target cells can be consistently inhibited by anti-HLA-A, B, and C and anti-beta 2 microglobulin antibodies. However, no evidence for allogeneic restriction in this system was apparent as (a) cytotoxic T lymphocytes (CTL) from one given individual could exert a cytotoxicity of a similar magnitude on different EBV-positive target cells, regardless of the number of HLA-A or B specificities shared by the effectors and targets; (b) CTL from IM patients were able to kill target cells without any HLA-A or B antigen in common; and (c) T5-1 variants lacking one or two HLA antigens at the A, B, or D locus are killed to the same extent as the parental cells. 7 of the 9 IM patients with detectable circulating anti-EBV CTL carried the HLA-A1 antigen, whereas none of the 16 IM patients lacking detectable peripheral CTL were HLA-A1 positive (mean specific lysis of T5-1 target cells by T cells from HLA-A1 positive patients: 29.3 vs. 0.6% in HLA-A1-negative patients) (P less than 10(-9)). These data suggest an HLA-A1-linked gene control of the magnitude of the anti-EBV CTL response. Thus, the HLA region appears to act at two different level sin the T-cell-mediated lysis of EBV-infected cells by controlling first, the development of anti-EBV and second, the expression of HLA-A, B, and C molecules involved as recognition structures at the target cell surface.


In vitro induction of T-lymphocyte-mediated cytotoxicity by infectious murine type C oncornaviruses.

We have developed a system to induce oncornavirus-specific secondary cytotoxic response in vitro. When Moloney strain of murine sarcoma virus-immune spleen cells were cultivated with purified infectious Moloney murine leukemia virus (M-MuLV) or with supernates of tissue culture cells containing infectious virus, a virus-specific secondary cytotoxic response directed against type-specific determinant(s) of M-MuLV was generated in vitro, as determined by a 4-h 51Cr-release assay. The effector cells were susceptible to the treatment with anti-Thyl.2 plus complement, but were unrelated to natural killer cells (NK), because they could not lyse some target cells specific for M-MuLV in both the induction phase and the interaction between effector cells and target cells. Furthermore, a product of the env gene of M-MuLV, perhaps gp70, appeared to be responsible for this response, because viruses with recombinations in the env gene between ecotropic M-MuLV and a xenotropic virus failed to induce a response. When infectious M-MuLV was exposed to UV-light at different doses, the ability of UV-treated M-MuLV to induce a secondary cytotoxic response decreased in parallel with infectivity, indicating that infectivity was necessary for the induction of this response.


Inhibition of collagen synthesis by mononuclear cell supernates.

Mononuclear cell infiltration and alteration in the connective tissues are prominent features of the inflammatory response in a number of diseases. To determine whether mononuclear cell products can modulate collagen synthesis, human peripheral mononuclear cells from normal donors were isolated by Ficoll-Hypaque gradient centrifugation and then incubated for 48 h with or without phytohemagglutinin. Confluent cultures of normal, human skin fibroblasts were incubated with [14C]proline and various amounts of dialyzed supernates from the mononuclear cell cultures. Labeled, newly synthesized collagen was estimated by [14C]hydroxyproline analysis, collagenase digestion, and chromatography on Agarose A-5m in sodium dodecyl sulfate. The total incorporation of [14C]proline was not significantly affected by addition of the mononuclear cell supernates, but as much as 90% decrease in the synthesis by the fibroblasts of labeled collagen was found relative to controls. Supernates from the phytohemagglutinin-stimulated cultures were more active than those from nonstimulated cells. These results suggest that mononuclear cells can synthesize a factor(s) which can selectively inhibit collagen synthesis.


Lymphocyte transformation induced by autologous cells. VIII. Impaired autologous mixed lymphocyte reactivity in patients with acute infectious mononucleosis.

The autologous mixed lymphocyte reaction (MLR) is severely impaired in patients with acute infectious mononucleosis. Reactivity returned during the course of convalescence. The allogeneic MLR was not impaired in these patients. B cells from patients with infectious mononucleosis do not stimulate autologous T-cell proliferation, and this observation appears to explain the cellular basis of the impaired autologous MLR in infection. Two explanations for the B-cell defect were considered: (a) the influence of serum factors on B-cell function and (b) the effect of Epstein-Barr virus infection.


The role of natural killer cells and antibody-dependent cell-mediated cytotoxicity during murine cytomegalovirus infection.

Definition of the functions by which the cellular immune system contributes to control of cytomegalovirus (CMV) infection should permit determination of the specific defects which result in the increased susceptibility to infection of immunosuppressed individuals. Using a murine model, we studied the cytotoxic lymphocyte response to murine CMV infection. This response was found to be biphasic. The initial phase extended from the 3rd to the 6th d after infection, was not genetically restricted, and correlated to a rise in numbers of natural killer (NK) and antibody-dependent killer (K) cells in spleens. The NK- and K-cell responses were preceded, by 24 h, by a rise in serum interferon levels, and occurred before the time when antibody could be measured in serum by neutralization. NK and K cells appear to develop the capacity for specific recognition of CMV-infected cells and the potential to contribute to control of the acute phase of CMV infection.


Expression of endogenous xenotropic retrovirus by methylcholanthrene-induced squamous cell carcinoma of the mouse respiratory tract.

As a model for human lung cancer, squamous cell carcinomas were induced by 3-methylcholanthrene in mouse tracheas which had been explanted to a subcutaneous site. The tumors that developed were examined for both ecotropic and xenotropic infectious murine leukemia virus (MuLV). From all squamous carcinomas--six out of six--a xenotropic MuLV was isolated. From some of the fibrosarcomas that occurred incidentally in our induction system, ecotropic MuLV was isolated. However, in the fibrosarcomas, no xenotropic MuLV at all was found.


Cyclic AMP derivatives stimulate the chondrogenic differentiation of the mesoderm subjacent to the apical ectodermal ridge of the chick limb bud.

Recent studies indicate that one of the major functions of the apical ectodermal ridge (AER) of the embryonic chick limb bud is to maintain mesenchymal cells directly subjacent to it (i.e., cells extending 0.4-0.5 mm from the AER) in a labile, undifferentiated condition. Furthermore, when mesenchymal cells are freed from the AER's influence, either artifically or as a result of normal polarized proximal-to-distal limb outgrowth, they are freed to commence cytodifferentiation. In a preliminary attempt to investigate at a molecular level the mechanism by which the AER exerts its "negative" effect on the cytodifferentiation of subridge mesenchymal cells, we have examined the effect of a variety of agents that elevate cyclic AMP levels on the chondrogenic differentiation of the unspecialized subridge mesoderm of the limb bud in an organ culture system. Dibutyryl- and 8-hydroxy-cyclic AMP elicit a dose-dependent increase in the rate and amount of cartilage matrix formation and a corresponding dose-dependent increase in sulfated glycosaminoglycan accumulation by subridge mesoderm explants. The stimulatory effect of suboptimal concentrations of cyclic AMP derivatives is potentiated by the addition of theophylline. The stimulatory effect is limited to cyclic AMP derivatives, since dibutyryl-cyclic GMP and 5'-AMP have no effect. Thus agents that elevate intracellular cyclic AMP levels stimulate the chondrogenic differentiation of the unspecialized subridge mesoderm of the embryonic chick limb bud.


Interspecific heterokaryons between oocytes and blastomeres of the mouse and the bank vole.

Interspecific hybrid cells were produced using Sendai-virus-mediated fusion of interphase blastomeres from 2-cell embryos with ovulated oocytes of the mouse and bank vole. Under the influence of the cytoplasm of oocytes (arrested in metaphase II) premature chromosome condensation occurs in the nuclei of blastomeres, thus implying that the cytoplasmic factor which induces chromosome condensation is not species specific, at least not between these two species.


Light-induced dephosphorylation of two proteins in frog rod outer segments: influence of cyclic nucleotides and calcium.

Two minor proteins of frog rod outer segments become phosphorylated when retinas are incubated in the dark with 32Pi. The proteins, designated component I (13,000 daltons) and component II (12,000 daltons), are dephosphorylated when retinas are illuminated. The dephosphorylation is reversible; the two proteins are rephosphorylated when illumination ceases. Each outer segment contains approximately 10(6( molecules of components I and II. These remain associated with both fragmented and intact outer segments but dissociate from the outer segment membranes under hypoosmotic conditions. The extent of the light-induced dephosphorylation increases with higher intensities of illumination and is maximal with continuous illumination which bleaches 5.0 x 10(5) rhodopsin molecules/outer segment per second. Light which bleaches 5.0 x 10(3) rhodopsin molecules/outer segment per second causes approximately half-maximal dephosphorylation. This same intermediate level of illumination causes half-suppression of the light-sensitive permeability mechanism in isolated outer segments (Brodie and Bownds. 1976. J. Gen Physiol. 68:1-11) and also induces a half-maximal decrease in their cyclic GMP content (Woodruff et al. 1977. J. Gen. Physiol. 69:667-679). The phosphorylation of components I and II is enhanced by the addition of cyclic GMP or cyclic AMP to either retinas or isolated rod outer segments maintained in the dark. Several pharmacological agents which influence cyclic GMP levels in outer segments, including calcium, cause similar effects on the phosphorylation of components I and II and outer segment permeability. Although the cyclic nucleotide-stimulated phosphorylation can be observed either in retinas or isolated rod outer segments, the light-induced dephosphorylation is observed only in intact retinas.


Walk-in patients' decisions about follow-up care.

This study examined the decisions patients made about obtaining follow-up care after an initial visit to a psychiatric walk-in clinic. Sixty-nine randomly selected patients who received a variety of ambulatory referrals were questioned by means of structured and ured to, and 70 per cent of the patients given medication took it substantially as prescribed. Completion of the referral was associated with being employed, not abusing drugs and alcohol, having a positive view of the walk-in clinic, and adherence to the medication regimen. Referral success was unrelated to sociodemographic characteristics, social integration, the nature of the intended disposition, or prior medical or psychiatric care. Patients who adhered to the disposition did not necessarily adhere to the medication regimen, and vice versa. Referrals were more successful when the patient had preceded the clinical encounter with an active appraisal of his situation. The decision to adhere was a complex and prolonged one in which the patient weighed many factors, of which the physician's suggested disposition was only one.


Neuroendocrine function in long-term pinealectomized male rats, following visual and audiogenic stress.

Intact, sham-pinealectomized and pinealectomized adult male rats were maintained for 10 weeks on a light : dark (L : D) cycle of 12 : 12,with lights on at 6 a.m. Subsequently they were acutely exposed to (1) visual or (2) audiogenic stress for periods of 2 or 30 min, immediately following which they were decapitated and serum ACTH, corticosterone, FHS, LH, PRL and TSH concentrations were determined. Serum ACTH and corticosterone levels were similar in control and operated groups following both types of stresses. Serum FSH and LH concentrations were elevated in pinealectomized animals as compared to controls, following 30 min of exposure to visual stimulation; no difference in these parameters was observed between the groups following audiogenic stress. Serum PRL levels tended to be lower in pinealectomized animals following both stresses. Serum TSH concentrations following visual stimulation were similar in all groups, but audiogenic stimulation resulted in elevated TSH levels as compared to controls. These data demonstrate that the pineal gland plays an integral role in the responses of the parvicellular neuroendocrine axes to acute neurogenic stress. Possible molecular bases for this involvement are discussed.


Models for ferric cytochrome P450. Characterization of hemin mercaptide complexes by electronic and ESR spectra.

Hemin coordinated with mercaptide sulfur as fifth ligand and various sixth ligands were investigated as models for cytochrome P450 in its native ferric low-spin state and its ligand complexes. Mixing the hemin with its ligands below -60 degrees C prevented the reduction of the hemin by mercaptide and made it possible to characterize each sample both by electronic and ESR spectra. Excess of mercaptide formed hemin-dimercaptide complexes with hyperporphyrin spectra with two Soret bands around 380 and 370 nm. The second mercaptide could be exchanged by other ligands with hydroxyl, phosphine, thioether, isocyanide, amine, imidazole, and pyridine groups. The comparison of these spectral data with cytochrome P450 substantiates mercaptide as the fifth ligand and makes a hydroxyl group a more likely candidate for the native sixth ligand than an imidazole group.


Catalysis of the disproportionation of superoxide by metalloporphyrins.

The efficiencies of several metalloporphyrin complexes at catalyzing the disproportionation of superoxide have been determined at pH 10 in both carbonate and borate buffer systems. Catalytic rate constants were obtained for the iron(III) and cobalt(III) derivatives of tetrakis(4-N-methylpyridyl) porphine, for tetraphenylporphinesulfonatoferrate(III) and for hemin. In addition, the effects of added bovine serum albumin and imidazole were studied. The order of catalytic efficiency is FeTMpyP greater than FeTMpyP(Im)2 greater than FeTPPS(Im)2 approximately FeTPPS approximately FeTPPS.BSA approximately Fe(EDTA) greater than or approximately CoTMpyP greater than hemin(Im)2 greater than or approximately hemin.


Ultrastructural basis for different pertechnetate uptake patterns by various human brain tumours.

Patterns of pertechnetate uptake were correlated with ultrastructural properties of the endothelial wall in 14 human brain tumours. In tumours with reduced uptake of the radionuclide, intercellular tight junctions were observed whereas absence of intercellular tight junctions was characteristic of all tumours with an increased uptake of pertechnetate. In some tumours with increased uptake, fenestrated endothelial wall was seen while in others non-fenestrated wall was evident. We concluded that intercellular junctions and not fenestrations affect the permeability of brain tumours to pertechnetate.


Morphological, immunocytochemical and biological characteristics of experimental rabbit brain tumors in tissue culture.

Brain tumors were induced in 3-month-old rabbits of either sex by repeated intravenous injections of N-methyl-N-nitrosourea. Twelve brain tumors (6 pleomorphic gliomas, 5 grade 2--3 astrocytomas, 1 grade 2--3 oligodendroglioma) were established in culture and, with the exception of 2 neoplasms, were propagated in vitro as permanent cell lines. The glial nature of all cell lines was ascertained at several passage levels by testing the cells for the production of S-100 and GFA. It could be shown that most cells of all lines fluoresced positively for the S-100 protein, albeit differences in intensity of fluorescence were clearly noted between cells of the same culture and between different cultures. In general, astrocytoma cell lines had the strongest fluorescence. Pleomorphic glioma cells but especially astrocytoma cells reacted positively also for the GFA protein. Surprisingly enough, isolated cells of the oligodendroglioma line also showed evidence of GFA production. Exposure of cultures of rabbit glioma cells to db-cAMP for 8--10 hr resulted in inhibition of cell proliferation and stimulation of process formation. Furthermore, positive fluorescence for the S-100 and GFA proteins was more intense in cells treated with db-cAMP than in untreated cells. The latter observation may indicate that production and/or accumulation of glial proteins also was enhanced during the stationary phase of cell cultures.


Involvement of calcium and cyclic AMP in controlling ixodid tick salivary fluid secretion.

Catecholamine-stimulated salivary fluid secretion (in vitro) by ixodid ticks is reduced by deletion or lowering the concentration of exogenous bathing medium Ca++. The Ca++ antagonist, verapamil, reversibly inhibits dopamine-stimulated secretion. Ionophore A-23187 is unable to induce glands to secrete. Studies in which labeled and unlabeled Ca++ flux were measured indicate that catecholamines induce release of calcium from intracellular stores during secretion. Cyclic AMP/theophylline-stimulated secretion is inhibited by verapamil, and the exclusion of calcium from the support medium. It is concluded that the primary catecholamine stimulus induces cyclic AMP formation and mobilization of Ca++ (intra- and extracellular). Cyclic AMP and calcium are thought to interact to control secretion within the fluid transporting cells of types II and III alveoli.


Pathogenicity of axenically cultivated Entamoeba histolytica, strain 200:NIH, in the hamster.

Entamoeba histolytica strain 200:NIH cultured axenically for about 15 years produced lesions and abscesses in inbred adult hamsters following intrahepatic, intraperitoneal, and intradermal inoculation. These amebae, even in much higher doses, inoculated into the ceca of adult and young hamsters failed to produce lesions or to become established there. On the other hand, 200:NIH axenic amebae passaged through hamster liver (substrain 200:NIH-L) were able to become established and to produce lesions in the ceca of very young hamsters (1- and 3-week-old), the degree of pathogenicity appearing to be inversely proportional to age of the hamster.


Renal transplantation in patients with bilateral Wilm's tumor.

Review of cases and of published reports of patients with bilateral Wilms' tumor revealed a significantly higher mortality rate in those who had received a renal transplant than in those who had not. The increased mortality is attributed to overwhelming sepsis resulting from chemotherapy, radiotherapy and immunosuppression. Growth of the tumor did not appear to be accelerated by immunosuppression and transplantation.


The effects of two analogs of dopamine on ganglionic transmission in the sympathetic nervous system.

Two aminotetralin analogs of dopamine were studied for their effects on ganglionic transmission in the sympathetic nervous system. Nerve activity (spontaneous firing or evoked action potentials) was recorded on a preganglionic nerve (splanchnic), a mixed nerve (lumbar chain) and several postganglionic nerves (external carotid branch and renal nerve). 6,7-Dihydroxy-2-dimethylaminotetralin and 5,6-dihydroxy-2-dimethylaminotetralin were observed to markedly inhibit spontaneous firing in the renal nerve, external carotid branch and lumbar chain. Splanchnic nerve activity was unaltered, 6,7-Dihydroxy-2-dimethylaminotetralin also depressed evoked responses to submaximal stimulation in the external carotid branch and lumbar chain. These results suggest a ganglionic site of action. Since functional vasomotor activity in the isolated perfused canine forelimb in response to preganglionic nerve stimulation was unaltered, it was concluded that 6,7-dihydroxy-2-dimethylaminotetralin may depress transmission only at certain ganglionic pathways.


Re-evaluation of the relationship between the positive inotropic effect of ouabain and its inhibitory effect on (Na+ + K+)-dependent adenosine triphosphatase in rabbit and dog hearts.

Previous studies have shown that in the ouabain-exposed rabbit heart, although positive inotropy and inhibition of (Na+ + K+)-dependent adenosine triphosphatase are induced concomitantly, the extent of inhibition of the enzyme remains constant when positive inotropy is washed out; and in the dog heart, if positive inotropy without arrhythmias is induced by ouabain, inhibition of the enzyme is not detected. The purpose of this work was the re-evaluation of these previous findings. Rapid recovery of the enzyme from small tissue samples was achieved by homogenization in 1 M KCl and centrifugation. When the enzyme was prepared by this method from ouabain-exposed rabbit and dog hearts, ouabain remained bound to the enzyme. The extent of inhibition of the enzyme was measured by the fluorimetric assay of K+-dependent 3-O-methylfluorescein phosphatase before and after removal of bound ouabain. Correlation between the extent of inhibition of this activity and that of (Na+ + K+)-dependent adenosine triphosphatase activity was established. Utilizing these refined methods, the following results were obtained. In the rabbit heart, positive inotropy and enzyme inhibition occurred concomitantly. Washout of the effect resulted in partial reactivation of the enzyme. In the dog heart, the previous findings were confirmed. The results are not inconsistent with the hypothesis that enzyme inhibition is the cause of the positive inotropic effects. They do suggest, however, the need for further testing of the hypothesis.


The kinetics of tubocurarine action and restricted diffusion within the synaptic cleft.

1. The kinetics of tubocurarine inhibition were studied at the post-synaptic membrane of frog skeletal muscle fibres. Acetylcholine (ACh) and (+)-tubocurarine were ionophoresed from twin-barrel micropipettes, and the membrane potential of the muscle fibre was recorded intracellularly. Tubocurarine-receptor binding was measured by decreases in the response to identical pulses of ACh. 2. The responses to both ACh and tubocurarine had brief latencies and reached their maxima rapidly. It is suggested that under these conditions the kinetics of tubocurarine action are not slowed by diffusion in the space outside the synaptic cleft. 3. After a pulse of tubocurarine, recovery from inhibition proceeds along a roughly exponential time course with a rate constant, 1/tau off approximately equal to 0.5 sec-1. This rate constant does not depend on the maximal level of inhibition and varies only slightly with temperature (Q10 = 1.25). 4. After a sudden maintained increase in tubocurarine release, the ACh responses decrease and eventually reach a new steady-state level. Inhibition develops exponentially with time and the apparent rate constant, 1/tau on, is greater than 1/tau off. When the steady-state inhibition reduces the ACh response to 1/n of its original level, the data are summarized by the relation, 1/tau on = n(1/tau off). 5. When the ACh sensitivity is reduced with cobra toxin, both 1/tau on and 1/tau off increase. Thus, the kinetics of tubocurarine inhibition depend on the density of ACh receptors in the synaptic cleft. 6. After treatment with collagenase, part of the nerve terminal is displaced and the post-synaptic membrane is exposed directly to the external solution. Under these circumstances, 1/tau off increases more than tenfold. 7. Bath-applied tubocurarine competitively inhibits the responses to brief ionophoretic ACh pulses with an apparent equilibrium dissociation constant, K = 0.5 microM. 8. In denervated frog muscle fibres, extrasynaptic receptors have a lower apparent affinity for tubocurarine. After a pulse of tubocurarine, inhibition decays tenfold more rapidly at these extrasynaptic sites than at the synapse. 9. It is suggested that each tubocurarine molecule binds repeatedly to several ACh receptors before escaping from the synaptic from the synaptic cleft and that the probability of this repetitive binding is enhanced because the nerve terminal presents a physical barrier to diffusion out of the cleft. Consequently, the receptor transiently buffer the concentration of tubocurarine in the cleft, and the macroscopic kinetics of inhibition are much slower than the molecular binding rates for tubocurarine.