A preliminary study of the superoxide dismutase content of some human tumors.

The cell cytosol superoxide dismutase (SODase) content of 46 human tumors was investigated. The extraction procedure of McCord and Fridovich was used with the epinephrine assay of Misra and Fridovich (J. Biol. Chem., 247; 3170-3175, 1975). The purpose of the study was to determine whether SODase could be reliably assayed from small, biopsy-sized pieces of tumor (0.5 to 1.0 g). In most cases it was possible to examined larger masses of tumor, which served as a control of the methodology. In this preliminary study SODase values, calculated from a standard curve derived from purified bovine blood SODase with a specific activity of 2584 units/mg, ranged from as little as 0.23 to as much as 160.5 units/g of tumor. These findings suggested that the procedures used might be feasable on a routine basis to determine the SODase content of tumors and its possible relationship to the radiation sensitivity of the tumors.

Plasma lactoferrin levels in pregnancy and cystic fibrosis.

Plasma lactoferrin levels were determined by radioimmunoassay for the different weeks of normal pregnancy, in normal healthy adults and in children with and without cystic fibrosis. The lactoferrin levels were higher in pregnancy than in both male and female normal adults and showed a slight progressive increase up to week 29 and thereafter remained high. Five our of seven children with cystic fibrosis had markedly raised plasma lactoferrin levels from six to 16 times higher than the mean of a control group of children.

Treatment of acute lymphoblastic leukemia-induced extreme hypercalcemia with pamidronate and calcitonin.

OBJECTIVE: To describe extreme hypercalcemia as the presenting feature of acute lymphoblastic leukemia in an 8-yr-old girl and the combined use of pamidronate and calcitonin for its treatment. DESIGN: Case report. SETTING: Pediatric intensive care unit. PATIENT: An 8-yr-old girl with 20.0 mg/dL serum calcium (reference range, 8.8-10.4 mg/dL) and 2.66 mmol/L ionized calcium (reference range, 1.13-1.32 mmol/L). INTERVENTION: Intravenous pamidronate and subcutaneous calcitonin. MEASUREMENTS AND MAIN RESULTS: Our patient presented with nausea, vomiting, lethargy, weight loss, fatigue, and weakness but, remarkably, did not exhibit electrocardiographic changes. Initial treatment with hydration at 8 mL x kg(-1) x hr(-1) and furosemide was ineffective. A single dose of 1 mg/kg intravenous pamidronate given over 24 hrs complemented by three doses of 5 units/kg subcutaneous calcitonin over 36 hrs lowered serum calcium to a normal range within 3 days. Side effects noted were hypocalcemia, hypomagnesemia, and hypophosphatemia. They were most pronounced 7-9 days after treatment, stabilized with supplementation, and returned to acceptable ranges by 1 month without need for ongoing electrolyte supplements. A renal computed tomographic scan did not show nephrocalcinosis. The patient remained free from recurrence of hypercalcemia 6 wks after initiating chemotherapy for acute lymphoblastic leukemia. CONCLUSIONS: Extreme hypercalcemia can be a presenting feature of acute lymphoblastic leukemia, but it may not result in life-threatening organ dysfunction. Combined treatment with pamidronate and calcitonin should be considered for treating hypercalcemia that does not respond to conventional therapy with hydration and furosemide.

High serum concentrations of aflatoxin in Nepal as measured by enzyme-linked immunosorbent serum assay.

1 Sera from 28 Nepalis, both patients and workers in a hospital in Banepa, Nepal were examined for AFB1 by enzyme-linked immunosorbent assay (ELISA). 2 This assay, previously validated using spiked sera, provides a sensitive rapid determination of serum aflatoxin (B1, G1 and Q1). 3 All 28 sera were positive with concentrations from 60 pg ml-1 to 10 ng ml-1. 4 These results suggest that consumption of aflatoxin in Nepal is high (greater than 50-800 ng kg-1 d-1). 5 No reports of the degree of contamination of food, human consumption or body fluid concentrations of aflatoxin in Nepal have been previously published. 6 Aflatoxin may contribute to the development of hepatocellular carcinoma, which is probably a common tumour in Nepal.

Intracellular Treponema pallidum in cells of a syphilitic lesion of the uterine cervix.

In an electron microscopic study of biopsy tissue from an ulcer of the human cervix uteri, organisms morphologically identical to T. pallidum were observed. Large numbers of the organisms were seen lying among collagen fibrils and between cells. T. pallidum was seen within vacuoles of some fibroblasts and epithelial cells. Within the nucleoplasm of several cells, treponemes were observed, surrounded by a clear zone which might represent a mucopolysaccharide outer layer. The siameter of the organisms was 171 nm., and the diameter of the external axial filaments was 25 nm., dimensions similar to those reported by others for T. pallidum.

Intracellular location of Treponema pallidum (Nichols strain) in the rabbit testis.

During investigations designed to obtain purified suspensions of virulent Treponema pallidum (Nichols strain), infected rabbit testicular tissue was routinely examined in the electron microscope. Morphologically typical T. pallidum were found intracellularly within the cytoplasmic substance of fibroblasts, interstitial and Leydig cells, and of spermatocytes. The importance of these observations to latency and treatment is discussed.

Ultrastructural studies of treponemes: location of axial filaments and some dimensions of Treponema pallidum (Nichols strain), Treponema denticola, and Treponema reiteri.

Ultrathin sections of Treponema pallidum (Nichols strain), T. denticola (microdentium), and T. reiteri have been studied in the electron microscope to determine the location of the axial filaments and some of the dimensions of these organisms. The axial filaments of T. pallidum (Nichols strain) have been seen to be tubular in cross section with an overall diameter of 21.0 +/- 0.73 nm, and an electron-lucent core of 8.0 nm. The filaments were found to lie on the outside of the organism which had only one membranous structure surrounding the protoplasmic core. These findings were in contrast to those obtained for T. denticola and T. reiteri where the axial filaments did not exhibit a hollow core and were located between an outer membrane and an inner membrane surrounding the protoplasmic core. The outside diameter of T. denticola was determined to be 224.9 +/- 2.83 nm, and that of T. reiteri as 331.0 +/- 4.15 nm, contrasting with T. pallidum (Nichols strain) which had a diameter of 163.0 +/- 1.9 nm.

Intranuclear crystalline zebra structures induced in human tumour cells by adenovirus type 5.

Intranuclear crystalline inclusions with leaf-like striated appearance, i.e. zebra structures, were observed by electron microscopy in adenovirus type 5-infected human cervical and bladder carcinoma cells at 4 to 6 days after infection.

Long-term incorporation of tritiated adenine into deoxyribonucleic acid and ribonucleic acid by Treponema pallidum (Nichols strain).

Treponema pallidum (Nichols strain), extracted in medium containing Eagle minimal essential medium 50% fresh, heat-inactivated normal rabbit serum, and 1.0 mM dithiothreitol, was incubated under 3% oxygen in the presence of tritiated nucleic acid precursors. [8-3H]adenine was incorporated with high efficiency into trichloroacetic acid-insoluble material; 2'-deoxyadenosine and uridine were incorporated in lower quantities, and thymine and thymidine were not incorporated. Incorporation of [3H]adenine was inhibited by penicillin G, mitomycin C, actinomycin D, and erythromycin, but was not affected by cycloheximide. Partial purification of nucleic acids from T. pallidum incubated with [8-3H]adenine for 36 to 72 h and subsequent treatment with ribonuclease and deoxyribonuclease revealed that 15 to 20% of the trichloroacetic acid-precipitable counts were resistant to ribonuclease but susceptible to deoxyribonuclease. A simple assay was developed in which NaOH treatment was used to distinguish incorporation into ribonucleic acid and deoxyribonucleic acid. Both ribonucleic acid and deoxyribonucleic acid synthesis continued for 6 days of incubation under 3% O2, whereas incorporation was limited to the first day of incubation in samples incubated under aerobic or anaerobic conditions. T. pallidum thus appears to be capable of significant de novo deoxyribonucleic acid and ribonucleic acid synthesis under microaerobic conditions.

Treponema pallidum (Nichols strain) in tissue cultures: cellular attachment, entry, and survival.

The interaction of Treponema pallidum (Nichols strain) with cultured cells was investigated under aerobic conditions. Cell monolayers derived from rabbit testicular tissue extended the survival of treponemes as indicated by active motility. Large numbers of organisms rapidly attached to cultured cells. Within 3 h, one to twelve actively motile treponemes were attached to 25 to 50% of the cells. In addition, T. pallidum attained intracellularity as early as 30 min after inoculation of the cell monolayers. In sharp contrast, T. phagedenis biotype Reiter and T. denticola did not attach and did not enter cultured cells. Most importantly, intracellular and/or attached T. pallidum retained virulence for at least 24 h. Similar observations of attachment and retention of virulence were detected with ME-180, a cell line derived from a human cervical carcinoma. Preliminary studies with superoxide dismutase indicated that this enzyme prolonged treponemal motility and retention of virulence in the presence of cultured cells. These data provide guidelines for further investigations of in vitro cultivation of T. pallidum.

Treponema pallidum (Nichols strain) in tissue cultures: cellular attachment, entry, and survival.

The interaction of Treponema pallidum (Nichols strain) with cultured cells was investigated under aerobic conditions. Cell monolayers derived from rabbit testicular tissue extended the survival of treponemes as indicated by active motility. Large numbers of organisms rapidly attached to cultured cells. Within 3 h, one to twelve actively motile treponemes were attached to 25 to 50% of the cells. In addition, T. pallidum attained intracellularity as early as 30 min after inoculation of the cell monolayers. In sharp contrast, T. phagedenis biotype Reiter and T. denticola did not attach and did not enter cultured cells. Most importantly, intracellular and/or attached T. pallidum retained virulence for at least 24 h. Similar observations of attachment and retention of virulence were detected with ME-180, a cell line derived from a human cervical carcinoma. Preliminary studies with superoxide dismutase indicated that this enzyme prolonged treponemal motility and retention of virulence in the presence of cultured cells. These data provide guidelines for further investigations of in vitro cultivation of T. pallidum.

Influence of oxygen tension, sulfhydryl compounds, and serum on the motility and virulence of Treponema pallidum (Nichols strain) in a cell-free system.

The motility and virulence of Treponema pallidum (Nichols strain) were monitored during incubation in a modified tissue culture medium to study the effects of oxygen tension and medium composition on survival of the organism. A basal medium of Eagle minimal essential medium with 50% fresh, heat-inactivated normal rabbit serum was used inasmuch as better survival occurred with 50% normal rabbit serum than with lower concentrations. Addition of 0.5 to 2.0 mM dithiothreitol or 2.0 mM dithioerythritol to the basal medium led to significantly longer retention of T. pallidum viability in the presence of 3% oxygen than under aerobic or anaerobic conditions. The results of this investigation lend support to the classification of T. pallidum as a microaerophilic organism and provide direction for the design of potentially successful culture systems, with or without tissue culture cells.