Age-related changes in responsiveness of various rat tissue lymphocytes to mitogens

The effect of age on the mitogen responses of rat lymphoid tissues was investigated. Evaluation was based on using the in vitro proliferative response of lymphocytes from various tissues of Fischer-344 rats (2, 7, 13, 19 and 25 months) using concanavalin A (Con A), phytohemagglutinin-P (PHA-P), pokeweed mitogen (PWM) and Mycoplasma neurolyticum. The stimulation index (S.I.) for cervical, mesenteric, thymic and splenic lymphocytes treated with Con A and PHA-P was greatest for 2-month-old rats and lowest for 19-month-old rats; however, no age-related change was observed with either PWM or M. neurolyticum. The levels of mitogenic responses for lymph nodes in the two different anatomical sites paralleled one another, with the cervical lymphocytes showing a greater response. The splenic lymphocytes responded less than either lymph node lymphocyte population. When PHA-P treatment of splenic lymphocytes followed the removal of the plastic adherent population, the S. I. of the resulting non-adherent population was comparable to the S. I. of other tissue lymphocytes; however, an age-related decrease was still observed. The PHA-P proliferative response of either the 7- or 19-month non-adherent population was suppressed by the 7-month adherent population and not by the 19-month adherent population i.e., adherent population interaction with non-adherent population decreases with age.     

Effect of selected antimutagens on the genotoxicity of antitumor agents

Cyclophosphamide (CP), bleomycin (BL), doxorubicin (DOX) and cisplatin (CISP) are potent antitumor drugs used worldwide against many forms of human cancer. As with most such agents, there can be physiological side-effects and the possible induction of mutations and other genotoxic effects in non-tumor cells. It is common for patients to ingest a host of food supplements to diminish the discomforting side-effects of therapy. Because these food supplements are often also rich in antimutagens that could also affect the biological efficacy of the antitumor drugs, we investigated if such antimutagenic agents were indeed antimutagenic to these antitumor drugs. Using the Salmonella/microsome bioassay, we tested CP, BL, DOX, and CP for mutagenicity in the presence and absence of the antimutagens ascorbic acid (AA), chlorophyllin (CHL) and (+)-catechin (CAT). AA was a very effective antimutagen against CISP and less effective against BL and DOX. It was not antimutagenic to CP. CHL was effective as an antimutagen against all four antitumor drugs, and CAT was a strong inhibitor of DOX mutagenicity, but had little effect on BL, CP and CISP. These data now provide a basis for future in vivo antitumor/antimutagen combination studies to determine if these antimutagens function in a manner to reduce genetic effects without having concomitant effects on intended antitumorogenicity of these therapeutic agents.     

Immunological responsiveness and adjunct immunotherapy in lung cancer

Immunocompetency was assessed before and after the operation in 40 patients with lung cancer by skin reaction against tuberculin (PPD) and dinitrochlorobenzene (DNCB), lymphocyte response to PHA, proportion of T-cells, macrophage migration inhibition test (MIT) and the presence of blocking factor. MIT was positive in 27 per cent and blocking factor was positive in 42 per cent. Immune response paralleled the clinical stage of the lesion. In curative resection cases, the immune response rose postoperatively, but declined in non-resectable or recurrent cases. The influence of postoperative radiation therapy, cancer chemotherapy and host mediated agents on the patients was observed. The feasibility of adjuvant specific immunotherapy is discussed.     

Retinoic acid and interferon alpha act synergistically as antiangiogenic and antitumor agents against human head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is an aggressive malignancy in which multiple independent lesions develop over time throughout the mucosa of the upper aerodigestive tract. Therefore, the comprehensive treatment of this neoplasm must include a chemopreventive arm to hold premalignant lesions in check, a role well-suited to antiangiogenic agents. Retinoic acid (RA) and interferon alpha (IFN-alpha), drugs with known biological activity against HNSCC when used individually, are also inhibitors of angiogenesis. Here we show that they are remarkably synergistic antiangiogenic agents able to inhibit both the growth and the neovascularization of HNSCC injected into the floor of the mouth of nude mice. The mechanism of action of these drugs as antiangiogenic agents was 2-fold. They decreased the angiogenic activity of the tumor cells, and they caused the endothelial cells to become refractory to inducers of angiogenesis. When tumor cells were treated in vitro with IFN-alpha A/D, there was a dramatic drop in their secretion of interleukin-8, the major angiogenic factor produced by these tumors. When combined with RA, which causes tumor cells to secrete an inhibitor of angiogenesis, there was a synergistic inhibition of both tumor cell growth and secreted angiogenic activity. The combination of RA and IFN-alpha also acted synergistically on endothelial cells by reducing their responsiveness to both interleukin-8 and tumor conditioned media. Doses of each drug could be reduced by two logs without loss of activity. When animals bearing human HNSCC tumor cells were treated systemically with a combination of RA and IFN-alpha A/D at doses that were ineffective when used alone, dramatic decreases in both tumor growth and tumor angiogenesis were seen. These data suggest that the use of antiangiogenic mixtures may be a particularly effective way to design future chemoprevention protocols against HNSCC.     

Effects of long-term intrarenal angiotensin II infusion on renal vascular responsiveness to vasoactive agents

1. We tested whether chronic intrarenal angiotensin II (AngII) infusion altered renal vascular responsiveness to vasoactive agents, which would provide evidence of vascular structural changes. 2. The renal blood flow (RBF) responses to renal arterial administration of bolus doses of acetylcholine, glyceryl trinitrate, AngII and noradrenaline were measured before commencement of and 1 day after cessation of 28 days intrarenal AngII infusion (0.5 ng/kg per min) in chronically instrumented conscious dogs. 3. The RBF responses to these vasoactive agents were unaltered by chronic intrarenal AngII infusion in conscious dogs. 4. These functional studies provide no evidence for renal vascular hypertrophy in response to chronic intrarenal AngII infusion in conscious dogs.     

Treatment of accidental extravasation of antitumor agents with dimethylsulfoxide and alpha-tocopherol

INTRODUCTION: The aim of this study was to test topical applications of dimethylsulfoxide and alpha-tocopherol for the prevention of ulcerations after antimitotic extravasation. METHODS: An open prospective study was conducted in 10 patients in 4 different chemotherapy wards who had experienced infusion accidents leading to phlebitis (4 cases) or cellulitis (8 cases) including 2 at implant sites. Topical application of the dimethylsulfoxide alpha-tocopherol combination was initiated within the first hours and continued for 3 to 15 days. One patient was given dimethylsulfoxide alone. RESULTS: Necrosis was never observed. The implant sites were preserved and remained functional. CONCLUSION: The absence of secondary ulcerations and the preservation of the implant sites are clear advantages of this topical combination which should be used as first line treatment. Favorable results have been reported in the literature while other techniques used depend on the antimitotic agent and give variable results.     

Aza and diaza bioisosteric anthracene-9,10-diones as antitumor agents

We compared 115 female and 115 male Brazilian alcoholics in terms of their social and demographic characteristics, as well as other characteristics associated with alcohol consumption. Women both began drinking and increased their consumption later than men. The incidence of attempted suicide was higher among women. Females used less illicit drugs. Male alcoholics were more frequently born in the city of S?o Paulo. As for adherence to treatment in an out-patient clinic, no significant differences were found between the sexes 3, 6, 9 and 12 months after initiation of treatment.     

Bronchioloalveolar carcinoma of the lung

Iodine-123-iodobenzamide (IBZM) is a specific antagonist of dopamine D2 receptors and usually is used to study neuropsychiatric disorders. It also has a substantial affinity for malignant melanomas. This has been attributed to specific dopamine D2 receptor binding on melanoma cells because melanocytes and dopaminergic neurons share the same ectodermal origin and are both able to produce melanin. However, IBZM binding to melanoma metastases occurs predominantly 24 hr after injection, which is much later than maximal specific D2 receptor binding is expected. Furthermore, IBZM binding is not consistent in melanoma patients. This points to another mechanism of IBZM binding to melanoma cells. The aim of this study was to characterize IBZM-binding metastatic melanoma patients clinically and histologically to shed light on the nature of this mechanism. METHODS: Twenty-one patients with proven or suspected metastases of a malignant melanoma entered this prospective study after surgical removal of the primary tumor. Whole-body scans, planar scintigrams and SPECT scans were performed 2-5 hr and 1 day after intravenous injection of 185 MBq IBZM. RESULTS: The suspected diagnosis of metastatic cancer was later confirmed in 17 patients by histology, clinical follow-up, x-ray, CT or other radiologic methods. Four patients were free of tumor tissue at the time of investigation and remained stable for 2 yr thereafter. Twelve of the 17 patients had a melanotic and 5 had an amelanotic subtype of the tumor. Iodine-123-IBZM accumulation occurred in the metastases of 10 of the 12 patients with melanotic melanoma and in 0 of the 5 patients with the amelanotic tumor type (p < 0.01; chi-square test). Furthermore, IBZM accumulation occurred in 0 of the 11 amelanotic metastases but in 20 of the 25 melanotic metastases (p < 0.001). The sensitivity is, thus, 83% for the detection of melanotic melanoma metastases on a patient basis and 80% on a lesion basis. Iodine-123-IBZM scintigraphy demonstrated one previously unknown metastasis. Six initially suspected lesions were not due to melanoma metastases and were IBZM-negative. No false-positive IBZM accumulations occurred in our patients. CONCLUSION: Iodine-123-IBZM binds to melanotic malignant melanomas with high specificity and moderate sensitivity but not to amelanotic melanomas. Our data suggest that the tracer does not bind to membrane dopamine receptors of the tumor but is built in or closely bound to intracellular melanin.     

Large cell carcinoma of the lung metastatic to nuchal muscle

An attempt to achieve problem-based examining by the structured assessment of presentations is described. Students can choose to participate in the scheme in teams and then elect to use their awarded mark instead of part of the formal examination assessment. The element of choice of the study or examination method is seen as being a valuable element of the scheme. The scheme can be introduced without radical revision of existing curricula or substantial investment of staff time, and meets some of the expressed desires of the UK General Medical Council in terms of the introduction of novel methods of assessment.     

Association of macrophage activation with antitumor activity by synthetic and biological agents

Treatment of normal BALB/c mice i.p. with a number of adjuvants, including pyran copolymer, the copolymer of polyinosinic and polycytidylic acids, Bacillus Calmette-Guérin, glucan, and dextran sulfate, rendered macrophages nonspecifically cytostatic for syngeneic tumor cells. Macrophage activation was highly dose dependent. The validity of the inhibition of DNA synthesis assay for measuring macrophage-induced cytostasis of target cells was proven by demonstrating a concurrent decrease in RNA synthesis and a reduction in viable tumor cell number. Moreover, conditioned supernatants from pyran-activated macrophages did not significantly decrease [3H]thymidine incorporation by freshly added leukemia cells. Biological or synthetic agents that activated macrophages were generally effective systemic antitumor agents against the M109 lung carcinoma. Drugs that did not activate macrophages, such as typhoid vaccine, tilorone, levamisole, WY-13876, and thymosin, were ineffective in prolonging the life of tumor-bearing mice. Pyran treatment i.p. was the most effective antitumor adjuvant in two separate tumor models, and suppression of tumor growth appeared to be related not only to an increase in macrophage tumoricidal function, but also to a larger influx of macrophages responding at the tumor site.     

Photodynamic antitumor agents: beta-methoxyethyl groups give access to functionalized porphycenes and enhance cellular uptake and activity

Porphycene photosensitizers bearing two or four methoxyethyl side chains were synthesized in nine steps from commercially available starting materials. Ether cleavage led to (hydroxyethyl)- and (bromoethyl)porphycenes that were converted to vinyl and benzo derivatives. Five of the side chain-functionalized porphycenes were biologically studied in comparison with two tetra-n-propylporphycenes. Porphycenes were incorporated in small unilamellar liposomes and incubated with cultivated SSK2 murine fibrosarcoma cells. Cellular uptake and phototoxicity 24 h after 5 J/cm2 laser light treatment were determined. The porphycenes tested were between 17 and 220 times more photodynamically active than the currently clinically used sensitizer Photofrin, although extinction coefficients of the porphycenes' irradiated bands are only approximately 10-fold higher. The LD50 concentration for SSK2 cells in the incubation medium was as low as (8.5 +/- 2.8) x 10(-9) M for tetrakis(methoxyethyl)porphycene. Two methoxy or hydroxy groups enhanced cellular uptake, three or four methoxy groups both enhanced and accelerated cellular uptake of tetraalkylporphycenes. Half-life times of the uptake processes varied between (0.14 +/- 0.04) and (14 +/- 4) h and cellular saturation levels between (1.2 +/- 0.2) and (26 +/- 3) pmol/10(5) cells. When individual uptake rates were accounted for, all porphycenes had a similar "cellular" phototoxicity, pointing toward a common mechanism of action. Evidence is presented for the assumption that cell membranes are the primary targets of the tested porphycenes and that membrane solubility may play a critical role in their photodynamic efficiency. The results show that nonionic polar side chain functionalities can strongly enhance cellular uptake and antitumor activity of lipophilic porphyrinoids and thus that the known lipophilicity/activity relationship can be reversed for very hydrophobic sensitizers.     

Multidisciplinary approach to potentially curable non-small cell carcinoma of the lung

The management of patients with non-small-cell lung cancer (NSCLC) is still evolving. Newer third-generation chemotherapy (paclitaxel [Taxol]-based; vinorelbine [Navelbine]/ cisplatin [Platinol]) is more effective than second-generation cisplatin-based chemotherapy for patients with stage IIIB and IV disease. The combined use of cisplatin-based chemotherapy with sequential or concurrent radiation therapy has improved the survival of patients with unresectable stage IIIA disease. Neoadjuvant cisplatin-based chemotherapy has improved the survival of patients with resectable stage IIIA disease compared to surgery alone. Combined-modality therapy is a fertile area of innovative clinical investigations for the majority of stage III resectable and potentially curable NSCLC patients, as well as those with locally advanced unresectable stage III disease. We expect therapy to substantially improve over the next few years. Cooperative groups should move quickly to incorporate third-generation chemotherapy into large randomized trials in order to redefine the standard of therapy for patients with this disease.     

Endothelin expression and responsiveness in human ovarian carcinoma cell lines

To elucidate the potential role of endothelins (ETs) as growth regulators in ovarian carcinoma cells in culture, expression of endothelins and their receptors were measured in two ovarian cancer cell lines (PEO4 and PEO14), together with the effect of the exogenous addition of endothelins on the growth of these cell lines in vitro. RT-PCR analysis of mRNA prepared from PEO4 and PEO14 indicated the presence of ET-1 and ET-3 mRNA. Immunoreactive ET-1-like peptide was found in media from cultures of both PEO4 (1.7 +/- 0.4 fmol/10(6) cells/72 h) and PEO14 (20.2 +/- 6.8 fmol/10(6) cells/72 h) cell lines. Radioligand binding studies using 125I-ET-1 and membrane fractions were consistent with PEO4 cells having two receptor sites of either high affinity (Kd = 0.065 nM, Bmax = 0.047 pmol/mg protein) or lower affinity sites (Kd = 0.49 nM, Bmax = 0.23 pmol/mg protein). Studies using membrane fractions of PEO14 cells indicated that this cell line has only a single lower affinity binding site (Kd = 0.56 nM, Bmax = 0.31 pmol/mg protein). However, RT-PCR analysis indicated the presence of mRNA from both ETA and ETB receptors in PEO4 and PEO14 cell lines. Exogenous addition of ETs to PEO4 and PEO14 cells at concentrations of 10(-10)-10(-7)M resulted in specific dose-dependent increases in cell number for ET-1 (with maximum effects at 10(-10) and 10(-9)M for PEO4 and PEO14, respectively) and ET-2 (maximum effects at 10(-8) and 10(-9)M for PEO4 and PEO14, respectively) but not for ET-3. Experiments on the growth of PEO14 cells using BQ123 (ETA-R) antagonist and "antisense" oligonucleotide against the ETA-R, in the absence of exogenous ETs, suggested that immunoreactive ET-1-like material secreted by PEO14 cells can affect their growth in an autocrine manner. These results would be consistent with ET-1 acting as a possible autocrine growth regulator in human ovarian carcinoma cells.     

Small bowel perforation secondary to metastatic lung carcinoma

Since 1961, there have been a total of seven patients with small bowel perforation caused by metastatic lung carcinoma reported in the literature. Perforation of the small bowel to metastatic lung carcinoma must be considered when evaluating older patients who have histories of heavy cigarette smoking and signs and symptoms suggestive of pulmonary neoplasia. Primary resection and end-to-end anastomosis of the perforated bowel is the treatment of choice. No patient with small bowel perforation secondary to lung carcinoma has survived more than four months.     

Comparative study of susceptibilities of germinated and ungerminated conidia of Aspergillus fumigatus to various antifungal agents

Conidia are used as inocula for the in vitro susceptibility testing of Aspergillus fumigatus. Since the MIC is defined on the basis of visible mycelial growth, conidia should germinate and produce sporelings (germinated conidia) for monitoring of the growth inhibition and fungicidal activity of a drug. If a compound is capable of inhibiting germination of conidia while affecting or not affecting the growth of the organism, the MIC obtained will be the concentration of the drug required for the inhibition of conidial germination but not necessarily that required for inhibition of the growth of the organism. We investigated the susceptibility of germinated and ungerminated conidia to amphotericin B, itraconazole, voriconazole, and SCH56592. The MICs of various antifungal agents for germinated conidia were almost identical to those obtained for ungerminated conidia. In addition, both the germinated and ungerminated conidia were killed with almost equal efficiency by all of the compounds tested when exposed to the drugs for 24 h. These results suggest that either germinated or ungerminated conidia could be used as inocula for in vitro susceptibility studies of A. fumigatus with identical results.     

Interference of bronchographic agents with lung surfactant

Dionosil Oily (a suspension of propyliodone crystals in peanut oil and powdered tantalum were introduced into the right principal bronchi of rabbit lungs. The left lungs were used as controls. Pressure-volume characteristics of excised lungs with Dionosil Oily or peanut oil demonstrated significantly reduced compliance on inflation at a pressure of 3-4 cm H2O. These lungs also retained less air on deflation and therefore demonstrated a significantly reduced stability index. Histological sections revealed microatelectasis closely associated with crystals and/or peanut oil. Lungs with tantalum powder were not measurably influenced by the bronchographic agents. Surface balance experiments with lung surfactant and synthetic dipalmitoyl phosphatidylcholine (DPPC) demonstrated an increased minimum surface tension due to the oil suspension of propyliodone, peanut oil and particles (propyliodone and tantalum). There is good evidence that the oil suspension of propyliodone reduced the surface activity of lung surfactant in situ. Particles also may prevent the minimum surface tension from reaching relatively low values if they enter the alveoli in sufficient quantities.