Expression of Mason-Pfizer and simian type C viruses in the presence of 5-iododeoxyuridine and dexamethasone

Production of infectious Mason-Pfizer monkey virus (M-PMV) was enhanced after treatment of the CMMT cell line with 2.5 x 10(-5) M dexamethasone phosphate (DXM). The reverse transcriptase (RT) activity and infectivity titers of treated culture fluids were enhanced by five- and tenfold, respectively. Along with stimulation of M-PMV synthesis, a simian type C virus (SCV) was also detected by electron microscopic and RT analyses. The SCV was serologically related to the endogenous baboon type C virus. 5-iododeoxyuridine (IUDR) also activated the SCV in the CMMT cell line while significantly inhibiting the production of infectious M-PMV. The activation of endogenous SCV by IUDR or DXM was transitory, since removal of these compounds from the growth medium resulted in the disappearance of SCV buds and the related RT activity; however, low levels of specific viral structural proteins continued to be synthesized intracellularly. Similarly, the enhancement of M-PMV production seen with DXM was lost when the treated cells were subcultured for 2 weeks in the absence of the hormone.

Histiocytosis X and compulsive water drinking: report of a case

We describe a patient with histiocytosis X and compulsive water drinking. The association of diabetes insipidus with histiocytosis X is well recognized, and this patient was initially considered to have diabetes insipidus. It was only after further testing that the proper diagnosis was made.

Postprandial plasma glucose, insulin, glucagon and triglyceride responses to a standard diet in normal subjects

Postprandial plasma glucose, insulin and triglyceride responses were determined in 12 normal subjects (7 male and 5 female) fed a standard diet composed of typical American foods; the three meals were identical for each subject. A significant postprandial rise in glucose and insulin was observed. They were closely related temporally in the early postabsorptive period. However, in the late post-absorptive phase insulin decline was generally slower than the glucose decline. A considerable difference in the glucose and insulin response was observed between males and females. Fasting plasma glucose and insulin concentrations were lower in the women. Following each meal the peak plasma glucose was lower in the women, but the difference was significant only following breakfast (p less than 0.02). The area under the glucose curve following breakfast was also lower (p less than 0.01) in the women. In the men the maximal postprandial glucose concentration and the postprandial glucose area remained stable throughout the day, but there was an increase in peak insulin concentration and insulin area after dinner. In contrast, in the women the maximal postprandial glucose concentration and the postprandial glucose area increased throughout the day, but the peak insulin concentration and insulin area did not change. Plasma trigylcerides increased with breakfast and remained elevated throughout the day. Both fasting and postprandial mean triglycerides were higher in the men, but this did not reach statistical significance. The circulating pancreatic glucagon concentration, determined in 4 subjects, was unaffected by meals and remained stable throughout the day.

Practical considerations in the development of a human cancer vaccine

Factors involved in the development of a human oncornavirus vaccine are discussed. The isolation and purification of subviral gp69/71 antigenic components enhance the feasibility of developing safe vaccine. The recent isolation of a C-type virus (the HL-23) from a human leukemic patient and its similarity to the simian sarcoma virus presents us with a unique opportunity to test the safety and potency of a vaccine in nonhuman primates.

Extraction of digoxin and its metabolites from urine and their separation by Sephadex LH-20 column chromatography

The efficiency with which serveral solvent systems extract digoxin and its metabolites from urine has been studied and column chromatography using Sephadex LH-20 has been used to separate digoxin and its metabolites. These procedures have been evaluated and used to study the excretion of 3H-digoxin-12alpha and its metabolites in urines collected serially in 7 patients and in bile in one. The percentage of the radioactivity excreted as metabolites in urine and bile was found to reach a peak within the first day and then to gradualy decline to minimal amounts in patients with advanced renal failure as well as those with good renal function. The maximum percentage measured as metabolites in 4 patients with the most advanced renal failure was 10%.

Pathologic hypofunction of the renin-angiotensin-aldosterone system

The literature now contains reports of many cases of aldosterone deficiency. Usually, the presenting features are persistent hyperkalemia and tendencies to serious urinary sodium loss and hypotension. A classification of defects leading to pathologic hypofunction of the renin-angiotensin-aldosterone system (RAAS hypofunction) is presented, with emphasis on idiopathic hyporeninemia (probably the most common). Criteria for diagnosis are (1) normal adrenal glucocorticoid function, (2) low aldosterone excretion under basal and stimulated conditions, and (3) renal tubular responsiveness to exogenous mineralocorticoid. The condition is effectively managed with mineralocorticoid replacement therapy and should be considered in the presence of unexplained persistent hyperkalemia, hyponatremia, or postural hypotension.

Detection of simian type-C particles in Mason-Pfizer virus infected cultures

A simian type-C virus has been detected in cultures chronically infected with Mason-Pfizer monkey virus (M-PMV). Simultaneous budding of M-PMV and type-C virus particles from the same cells was observed in cultures incubated at 37 or 40 degrees C. However, the frequency of such cells was greater in cultures grown at 40 degrees C. Although clusters of type-C viral buds were seen at the surface of the cells, extracellular mature type-C particles in cell pellets or concentrated virus preparations were very rarely found. The increase in frequency of type-C buds was found to be transitory since cultures adapted to growing at the high temperature demonstrated budding type-C particles only occasionally. Cultures producing type-C buds were found to contain, in addition to M-PMV antigens, serological activity with polyvalent antisera produced against multiple structural components of endogenous baboon virus (BV) or simian sarcoma virus (SiSV). The reactivity, however, was found not to be serologically related to the major SiSV P28 core protein.

Interactions between endogenous baboon type-C virus and oncogenic viruses. I. Syncytium induction and development of infectivity assay

Cells releasing the endogenous baboon virus (BV) can interact with human KC cells containing the Rous sarcoma virus (RSV) genome, resulting in cell fusion and syncytium formation. This interaction has been utilized in the development of a sensitive infectivity assay for BV. The titration pattern is of a one-hit type, demonstrating a linear relationship between virus concentration and number of syncytial plaques obtained in the KC co-cultivation assay. Endpoint titration comparisons indicate that the KC test is as sensitive as the immunofluorescence or the RNA-directed DNA-polymerase assays. Attempts to develop an XC test for BV failed, indicating that while BV can interact with the RSV genome it will do so in the human KC cells and not in the rat XC cells. Syncytia are also induced when KC cells are directly exposed to cell-free BV; however, a linear dose relationship is not obtained. When syncytium-positive KC cultures are passaged, the syncytia disappear and a chronic BV infection is established. These KC-BV cells then lose the ability to interact with either the endogenous cat RD-114 virus or the Mason-Pfizer virus which are known to form syncytia with KC cells.

Jaundice due to carbimazole

On three occasions, a 63 year old housewife with hyperthyroidism developed a reaction which included fever, pruritus, malaise, and, on one occasion, jaundice one to 17 days after taking carbimazole. Challenge with carbimazole was followed within 12 hours by abdominal pain, pruritus, and increased serum transaminase levels. Light microscopy of a liver biopsy showed increase of portal zone cellularity over the control and the electron microscopy revealed fine structural changes compatible with drug-related liver injury.

Late results of aortic homograft reconstruction of the right ventricular outflow tract in infants and children

33 infants and children between 4 months and 14 years have undergone successful reconstruction of the right ventricular outflow tract with adult sized fresh aortic homografts. The late results have been analysed and it is concluded that satisfactory results can be obtained even in infants and that the operation should be performed early to prevent secondary changes in the heart and lungs.

Competition radioimmunoassay for mason-pfizer monkey virus: comparison with recent isolates

The major core protein of Mason-Pfizer monkey virus was purified by DEAE ion exchange column chromatography and shown to be 27,000 daltons (p27). Following the characterization of monospecific antisera prepared against p27, a radioimmunoassay was developed with these reagents and competition experiments were done with come of the recent M-PMY-like isolates as well as with other oncornaviruses. Results suggest that three of the viruses tested, AO, X-381 and FTP-1, are similar to M-PMV while J-96 virus is related, but not identical, to M-PMV. It is also shown that competition RIA can be used successfully to detect the presence of viral proteins in tissue homogenates and cell extracts.