Modelled evaluation of multi-component meningococcal vaccine (Bexsero®) for the prevention of invasive meningococcal disease in infants and adolescents in the UK.

Neisseria meningitidis is the main cause of bacterial meningitis and sepsis in the UK, and can potentially be lethal or cause long-term sequelae. Bexsero® (4CMenB) is a new multi-component vaccine approved by the European Commission for use in individuals aged ⩾2 months. A theoretical transmission model was constructed to assess the long-term effectiveness of Bexsero compared to standard care. The model was populated with UK-specific demographic data and calibrated to ensure that the transmission dynamics of meningococcal disease in the UK were adequately simulated. The model showed the best strategy to be a routine vaccination programme at ages 2, 3, 4, 12 months and 14 years combined with a 5-year catch-up programme in toddlers aged 12-24 months and adolescents aged 15-18 years. This would lead to a 94% reduction in meningococcal cases or 150 000 cases and 15 000 deaths over a 100-year time-frame.

Trans-crustal structural control of CO2-rich extensional magmatic systems revealed at Mount Erebus Antarctica.

Erebus volcano, Antarctica, with its persistent phonolite lava lake, is a classic example of an evolved, CO2-rich rift volcano. Seismic studies provide limited images of the magmatic system. Here we show using magnetotelluric data that a steep, melt-related conduit of low electrical resistivity originating in the upper mantle undergoes pronounced lateral re-orientation in the deep crust before reaching shallower magmatic storage and the summit lava lake. The lateral turn represents a structural fault-valve controlling episodic flow of magma and CO2 vapour, which replenish and heat the high level phonolite differentiation zone. This magmatic valve lies within an inferred, east-west structural trend forming part of an accommodation zone across the southern termination of the Terror Rift, providing a dilatant magma pathway. Unlike H2O-rich subduction arc volcanoes, CO2-dominated Erebus geophysically shows continuous magmatic structure to shallow crustal depths of < 1 km, as the melt does not experience decompression-related volatile supersaturation and viscous stalling.

A randomized targeted amino acid therapy with behaviourally at-risk adopted children.

BACKGROUND: Increasing numbers of children are at-risk for behavioural and emotional disorders, a phenomenon contributing to increased use of pharmacological interventions for paediatric clients. Adverse side effects and other risks associated with pharmacological approaches have helped fuel interest in nutritional interventions for behaviourally at-risk children. METHODS: The current randomized clinical trial evaluates the efficacy of a neurochemical intervention involving the glutamine and glutamate analogue L-theanine and 5-hydroxytryptophan, the precursor for serotonin, with children adopted from traumatic backgrounds. RESULTS: Results include significant increases in urinary levels of the biomarkers for serotonin and gamma-aminobutyric acid, coupled with significant decreases in parent reports of the children's behaviour problems. CONCLUSIONS: While further research is needed, these initial findings are encouraging and are consistent with a growing number of studies indicating the efficacy of nutritional approaches to help behaviourally at-risk children.

Effect of scheduling of combinations of 5-(3,3-dimethyl-1-triazeno)-imidazole-4-carboxamide and 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea on the Harding-Passey and Cloudman S91 mouse melanomas.

Harding-Passey mouse melanoma (HP) cells (10(6)) were administered i.p. to female BALB/c x DBA/2 F1 (hereafter called CD2F1) mice on Day 0. We showed earlier (H. Z. Hill, et al., Arch Surg., 114: 135-138, 1979) that a single dose of 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) administered on Day 0 or on subsequent days was equally effective regardless of the day of administration. We now show that a single dose of 10 mg of 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU) per kg was most effective in prolonging survival of HP-bearing CD2F1 mice when administered on Day 0. There was then a decline in effectiveness to Day 10, at which time the increase in survival of the drug-treated animals was no longer significant. The effect of sequential scheduling of DTIC and MeCCNU on HP was studied. The first drug was given on Day 0 or on Day 10. The second drug followed on the same day or on subsequent days. The greatest enhancement of survival was seen when DTIC was administered on Day 0 and MeCCNU on Day 1. Nine of 10 mice on this schedule were cured. When treatment of HP was started on Day 10, the most enhancement was again seen for DTIC on Day 10 and MeCCNU on the next day. Reversal of the order of the two drugs produced less prolongation of survival and fewer cures. The effect of scheduling two doses of DTIC was also studied using the HP model. The first dose was given on Day 0 or on Day 10. The second dose produced the greatest enhancement of survival when administered 3 to 4 days after the first dose, but the enhancement was less than that seen when DTIC was followed by MeCCNU. For comparison, the two drugs were also studied in female DBA/2 mice carrying the Cloudman S91 melanoma. In combination, on Day 0, in only one of three experiments was survival prolonged beyond the controls. Other schedules were ineffective. The enhancement seen when HP-bearing CD2F1 mice are treated with the best combination of the two drugs is clearly not seen with S91. The results imply that dosage scheduling in the treatment of murine melanomas must be individualized. Extrapolation to the human situation suggests the same conclusion.

Failure of amygdalin to arrest B16 melanoma and BW5147 AKR leukemia.

Parenteral amygdalin was found to be ineffective in C57BL/6 mice with B16 melanoma and in AKR mice with BW5147 lymphatic leukemia, in doses ranging from 50 to 5000 mg/kg.

Effects of 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide, 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea, and L-phenylalanine mustard on B16, Cloudman S91, and Harding-Passey mouse melanomas.

The effects of 5-(3,3-Dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC), 1-(2-chloroethyl)-3-(4-methylcyclohexyl)-1-nitrosourea (MeCCNU), and L-phenylalanine mustard (L-PAM) have been compared by using three i.p. transplanted mouse melanomas: the B16 melanoma in C57BL/6 mice; the Harding-Passey (HP) malanoma in BALB/c X DBA/2F1 (hereafter called CD2F1) mice; and the Cloudman S91 melanoma in DBA/2 mice. HP melanoma responds well to all three drugs. S91 responds only to L-PAM and MeCCNU. DTIC may accelerate death in mice bearing this tumor. B16 responds well to L-PAM and moderately well to MeCCNU and to multiple injections of DTIC. The best response to DTIC and MeCCNU is given by HP, while the best response to L-PAM is given by S91. Tumor cell-doubling times were found to be 1.5 days for B16, 2 DAYS FOR HP, and 3 days for S91. HP would seem to be the most responsive malanmoma with respect to the 3 agents studied. This may be due to an interaction between the chemotherapeutic agents and the host immune response, since the HP tumor arose in a noninbred mouse and is thus nonsyngeneic with the CD2F1 host. All three tumors appear to be interesting biological models for studying drug combinations and combined therapeutic modalities against melanoma.

A prospective evaluation of 5-fluorouracil plus cisplatin in advanced squamous-cell cancer of the head and neck.

Recent studies have shown improved efficacy of chemotherapy in patients with advanced squamous-cell cancer of the head and neck. Our purpose was to evaluate prospectively the activity of cisplatin plus 5-fluorouracil (5FU) in 37 patients with advanced stage IV squamous-cell cancer of the head and neck. There were two groups. Group 1 consisted of 19 previously untreated patients with either T4 or N3 disease. They received 100 mg/m2 cisplatin (days 1 and 28) and 120-hour infusion of 1,000 mg/m2/24 hours 5FU (days 1 to 5 and 28 to 32). They subsequently were offered preoperative radiotherapy (RT) and surgery. Group 2 consisted of 18 previously treated patients. They received 5FU and cisplatin in the same dosage every 28 days for either recurrent or metastatic disease. It was found that in group 1 there was an 84% response rate (five complete responses (CR) and 11 partial responses (PR) ). Three of those with PR achieved a CR after RT. Seven patients have had RT plus surgery and are disease free at 8 to 27 month follow-up. Six patients (one CR, five PR) refused surgery and progressed within 4 months. In group 2 there was an 11% response rate after two cycles (two PR), three patients had a minimal response (MR, less than 50% response) and received a mean of four cycles of treatment. Three patients with stable disease received a mean of four cycles of chemotherapy until progression. Two of 11 patients who had received previous chemotherapy plus RT showed an MR; nine of these patients had shown a response to their previous chemotherapy. Only one of 14 patients who had RT plus chemotherapy had a PR, and three had MR. Of five patients who had previous surgery, only one had a PR. All five had received chemotherapy as well. It was concluded that 5FU plus cisplatin is an effective combination in previously untreated patients. In previously treated patients with recurrent disease, there is a substantially lower response rate.

Activity of cancer chemotherapeutic agents against human colorectal carcinomas grown as primary tissue culture.

Improved procedures are described for the seeding of primary cultures from human colon adenocarcinoma and for the use of these cultures in the evaluation of drug effects. Two of the specimens studied were xenografts maintained in athymic (nude) mice, while the other six were biopsies obtained directly from patients. Tumor cells obtained directly from the patients proliferated in defined hormone-supplemented medium to the exclusion of other cells. In drug-response studies with cultures from a colon tumor biopsy all four drugs studied (4'-deoxydoxorubicin, 4'-O-methyldoxorubicin, 5-fluorouracil, and 1,3-bis-[chloroethyl]-1-nitrosourea) inhibited growth of the cells within 3-6 days after drug treatment. On an equitoxic dose basis (LD10 in mice), 4'-deoxydoxorubicin appeared to be the most active drug. This drug also showed dose-dependent activity against one of the xenografted tumors in vitro. In dose-response studies with cultures from another patient's colon tumor, doxorubicin and 5-fluorouracil showed significant activity against the tumor 10 days after the drug treatment with concentrations at 1X and 10X average peak plasma levels.

Irradiation of cells attached or suspended by rubber policeman or by trypsin influences the extent of DNA strand breaks induced by ionizing radiation.

Chilled B16CL4 mouse melanoma cells in phosphate-buffered saline were exposed to ionizing radiation before or after harvesting by gently scraping with a rubber policeman. Cells irradiated when attached had fewer DNA strand breaks than cells that were irradiated in suspension. Dose-response studies indicate that the rate of induction of DNA strand breaks by ionizing radiation is 1.5-fold greater in suspended cells. Irradiation after release of the cells by trypsinization also results in more breaks than irradiation when attached, but this method of harvest is not as damaging as release by rubber policeman. Strand breaks in unirradiated cells are unaffected by the method of cell harvest. These studies suggest that, in radiation studies, care should be exercised to avoid the introduction of artifacts resulting from the methods used to harvest and irradiate cells.

A radiation resistance factor in cultured Cloudman S91 mouse melanoma cells.

The gamma-ray survival of a radiation-sensitive amelanotic subclone of Cloudman S91 mouse melanoma, S91/amel, is increased by the presence in the tissue culture dishes of heavily irradiated cells from the same cell line (amel-HRCells) and from clonally related melanotic S91/I3 radioresistant cells (I3-HRCells). The D0 of the target S91/amel cells increases from 1.25 to 2.08 Gy in the presence of 60,000 heavily irradiated S91/amel cells per dish. The presence of I3-HRCells in dishes of target S91/I3 cells does not increase their radioresistance. Comparable numbers of I3-HRCells are more effective than amel-HRCells at increasing survival of target S91/amel cells irradiated with 3 Gy of gamma rays. Conditioned medium from the S91 melanoma cells also increases the radioresistance of S91/amel, but is not as effective as the HRCells. Unirradiated cells can condition the medium as effectively as irradiated cells. It is concluded that the radiosensitive mouse melanoma cell line is made significantly more resistant by a diffusible cellular factor(s) elaborated more proficiently by radiation-resistant cells.

Melanin both causes and prevents oxidative base damage in DNA: quantification by anti-thymine glycol antibody.

The present study employs immunological methods to measure modified bases in DNA. A polyclonal antibody specific for thymine glycol was used to quantify the level of thymine glycol in calf thymus DNA gamma-irradiated in solutions containing varying concentrations of DOPA-eumelanin. Melanin decreased the number of thymine glycols produced by 200 Gy at low melanin concentrations. At high melanin concentrations, the number of thymine glycols increased. Thymine glycol was also produced in unirradiated DNA-eumelanin mixtures. DOPA-eumelanin was found to produce single-strand breaks in supercoiled phi X174 RF DNA. The breaks were measured by conversion of form I to form II as detected by agarose gel electrophoresis. The level of damage produced by melanin could be modulated by agents known either to stabilize or to scavenge active oxygen species. These studies demonstrate that melanin can both scavenge and generate active free radicals.

Dacarbazine and melphalan. Enhancement by dosage scheduling of the effect in combination treatment on the Harding-Passey melanoma in C3D2F1 mice.

The best combination and schedule for dacarbazine and melphalan with the Harding-Passey melanoma in C3D2F1 mice is achieved when dacarbazine is administered first, followed by melphalan, given on either the day of dacarbazine therapy or the first three days after dacarbazine is given. When dacarbazine is given first, followed by melphalan on day 0, 1, 2, or 3, the effect of the two drugs is considerably more than additive. Other schedules reduce the outcome to a simple additive effect, or to an outcome that is less than additive, in which the combination is less effective than melphalan used alone. The effect of variations in the order and schedule of drug administration should be investigated in future trials of cancer chemotherapeutic agents, since profound effects may occur with these variations.

Effects of sodium cyanate in mice bearing B16 melanoma.

Sodium cyanate injected IP at a dose level of 200 or 250 mg/kg caused a 90% or greater inhibition of the incorporation of [3H]thymidine into DNA of B16 melanoma transplanted SC in mice. Despite the inhibitory effect of sodium cyanate on precursor incorporation into DNA, no significant effect on host survival was observed when sodium cyanate was administered as a single agent in the diet, in drinking water, or by IP injection to mice that had received IP transplants of B16 melanoma. The action of melphalan and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) in prolonging the survival time of melanoma-bearing mice was not enhanced by combined treatment with sodium cyanate. However, combined injections of sodium cyanate and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) increased the survival of tumor-bearing mice significantly more than injections of BCNU alone at a lower dose than the maximum tolerated one. These data and other studies suggest that B16 melanoma may be less responsive to the action of sodium cyanate than are murine leukemic cells or rat hepatomas.

Adjuvant chemotherapy in large-bowel cancer: demonstration of effectiveness of single agent chemotherapy in a prospectively controlled,, randomized trial.

In a prospectively randomized study, the effect of adjuvant chemotherapy with 5-FU on survival and recurrence rates was analyzed in 299 evaluable patients with colorectal carcinoma who either underwent a curative or a palliative resection. In the treatment group, chemotherapy consisted of the intravenous administration of 12 mg/kg daily of 5-FU for 4 consecutive days, then 6 mg/kg on alternate days, to the point of toxicity, or to a maximum of five doses, followed by 12mg/kg weekly for 1 year. Some degree of drug toxicity was seen in the majority of patients, was rarely severe, and there have been no drug-related deaths. Analysis of the survival curves and disease-free interval curves reveal definite evidence of drug benefit in two unfavorable subgroups, namely patients with Dukes C tumors and in patients whose tumor was located in the rectum. In the chemotherapy groups, patients who were treated to toxicity (WBC less than 4000 mm3), the disease-free interval was significantly longer than the nonleukopenic patients. We conclude that the addition of 5-FU to the surgical treatment of colorectal carcinoma provides a small, but significant benefit in patients with colorectal cancer in certain unfavorable subgroups, namely patients with Dukes C lesions and patients with rectal carcinoma.

A multitherapy resistance factor from melanoma reveals that killing by near UV is different from genotoxic agents.

A diffusible multitherapy resistance factor (MTRF) is produced by Cloudman S91 melanoma cells in vitro. The MTRF decreases sensitivity of the target cell line, S91/amel, to gamma-irradiation, UVC (200-280 nm) and mitomycin C (MMC). In the present study, we demonstrate that MTRF also increases the survival of S91/amel after exposure to actinomycin D (AMD) and vinblastine (VBL). The MTRF is thus effective when target cells have been exposed to five genotoxic agents that act by different mechanisms. It does not alter the response to the same five agents of the S91/I3 producer cells, which are presumably saturated with the factor. The factor has no effect on the survival of S91/amel cells that have been exposed to lethal doses of near monochromatic UVB (280-320 nm) or UVA (320-400 nm) or to polychromatic FS20 lamps. The lack of effectiveness of MTRF after cells have been exposed to near (300-400 nm) UV radiation indicates that in this wavelength range, S91 melanoma cells are killed by mechanisms that are different from the lethal effects of the five genotoxic agents (gamma-irradiation, UVC, MMC, AMD and VBL) to which the target cells demonstrate a response.

Comparative action spectrum for ultraviolet light killing of mouse melanocytes from different genetic coat color backgrounds.

The photobiology of mouse melanocyte lines with different pigment genotypes was studied by measuring colony-forming ability after irradiation. The cell lines were wild-type black (melan-a) and the mutants brown (melan-b) and albino (melan-c). Four lamps emitting various UV wavelengths were used. These were germicidal (UVC, 200-280 nm), 82.3% output at 254 nm, TL01 (UVB, 280-320 nm), 64.2% at 310-311 nm, FS20, broadband with peak output at 312 nm and Alisun-S (UVA, 320-400 nm), broadband with peak output at 350-354 nm. Appropriate filtration reduced the contaminating UVC to nonlethal levels for the longer waverange lamps. Wild-type melan-a was resistant to UVC and UVA compared to the other two cell lines, but the differences were small. The melan-c cell line was more resistant to UVB and markedly more resistant to FS20 than the pigmented lines. With the exception of FS20 responses, melan-b was more sensitive than melan-a to killing by the various UV lamps. There were more pyrimidine dimers (cyclobutane dimers and 6-4 photoproducts) produced in melan-a than in melan-c cells by UVC, UVB and FS20 lamps. Unlike melan-c, melan-a and melan-b showed a strong free radical signal of melanin character with a detectable contribution of pheomelanin-like centers. The contribution of pheomelanin was higher in melan-b than in melan-a, while the total melanin content in these two cell lines was comparable. The abundant melanin granules of wild-type melan-a melanocytes were well melanized and ellipsoidal, whereas those of melan-b melanocytes tended to be spherical. In the albino line (melan-c) the melanocytes contained only early-stage melanosomes, all of which were devoid of melanin. The results indicate that pigment does not protect against direct effect DNA damage in the form of pyrimidine dimers nor does it necessarily protect against cell death. High pigment content is not very protective against killing by UVC and UVA, and it may photosensitize in UVB the very wavelength range that is of greatest concern with respect to the rising incidence in skin cancer, especially melanoma. It is clear from these studies that, in pigment cells, monochromatic results cannot predict polychromatic responses and that cell death from solar irradiations is a complex phenomenon that depends on more than DNA damage.

Influence of an autocrine multitherapy resistance factor on radiation responses of melanoma cells.

An autocrine multitherapy resistance factor (MTRF) produced by a radioresistant subclone of S91 mouse melanoma (S91/I3) causes an increase in radioresistance of a radiosensitive subclone (S91/amel). MTRF has no effect on the survival of S91/I3, which is already relatively resistant to gamma-irradiation. In this study, we examined the effect of MTRF in the form of S91/I3 conditioned medium or as S91/I3 heavily-irradiated cells (I3-HRCells) on cellular responses of S91/amel cells after exposure to gamma-rays. Target S91/amel cells retained more than half of their ability to respond to rescue by MTRF on day 4 after exposure to 3 Gy. Continuous presence of MTRF during colony formation was necessary for maximum plating efficiency. Although the extent of double strand DNA breakage and repair was the same in S91/amel and S91/I3, split-dose recovery experiments with MTRF revealed previously undetected repair of sublethal damage in S91/amel cells. MTRF did not alter the extent of potentially lethal damage repair (PLDR) in S91/I3 or S91/amel. S91/amel cells were more responsive to MTRF if they had been harvested from confluent dishes, while S91/I3 cells produced a more effective factor if they had been harvested in exponential phase. These findings demonstrate that MTRF has unique properties. It does not appear to be involved in genome repair since it does not alter the extent of PLDR and it is effective when added to cells after complete split-dose recovery has occurred.

Influence of an autocrine diffusible resistance factor on cell survival after exposure to therapeutic agents.

A subclone of Cloudman mouse melanoma cells (S91/I3) produces a resistance factor (RF) that increases the survival of a different but related subclone, S91/Amel, after exposure to either ultraviolet C (UVC) radiation or to mitomycin C (MMC). The presence of RF was deduced from experiments in which heavily irradiated S91/I3 cells were plated with the target S91/Amel cells. The effect of RF was also present in cell-free conditioned tissue culture medium (CM) from S91/I3 cultures. These results extend previous findings that both subclones produce an autocrine resistance factor (RF) that alters the radiation response of target S91/Amel cells making them less sensitive to death by low linear energy transfer (LET) ionizing radiation. S91/I3 cells are radioresistant relative to S91/Amel and produce the RF more effectively than S91/Amel. S91/I3 cells do not respond to the RF, being themselves, presumably, maximally stimulated. The significant findings are (1) the RF is effective at decreasing the killing of the target cells using cytotoxic agents that operate by different mechanisms; (2) The relative sensitivities of S91/Amel and S91/I3 to the toxic agents is not a factor in the responses of these cells to the RF: S91/Amel survivals are increased by the RF, those of S91/I3 are not; (3) the RF is elaborated by the melanoma cells whether or not they have been irradiated; it is, apparently, a normal cell product; (4) the RF is effective when added after the cytotoxic insult; its presence is not required during irradiation or drug treatment. The RF appears to act by novel mechanisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapeutic resistance: characterization and inactivation by specific antiserum of a putative protein family produced by tumour cells.

A multitherapy resistance (MTR) factor produced by Cloudman S91 mouse melanoma cells rescues a responsive cell line after gamma-irradiation, short wavelength ultraviolet light, mitomycin C, vinblastine and actinomycin D. A similar activity with respect to ionizing radiation is now shown to be produced by human melanoma cells and by both human and mouse breast cancer cells but not by five normal cell lines. In these studies, the factor produced in serum-free conditioned medium (SFCM) by Cloudman S91/I3 cells is further characterized. Its activity in a clonogenic assay using related Cloudman S91/amel cells is destroyed by trypsin but not by DNase and is stable for at least 8 days at a variety of temperatures including 37 degrees C. Molecules greater than 30 kDa from SFCM collected from S91/I3 cells were concentrated and separated by preparative zonal electrophoresis (PZE). Bioactivity was present in both the cathode- and the anode-running fractions. The active acidic (anode) fractions were analysed by preparative isoelectric focusing. Bioactivity was present between pI 3.5 and 4.2. These PZE fractions were also used to immunize two rabbits, both of which produced antiserum that abrogated the bioactivity of SFCM and of the PZE cathode fractions. Antiserum also decreased the survival of irradiated S91/I3 producer cells that do not respond to SFCM but nonetheless must require MTR proteins for the expression of radiation resistance. These studies present a model for the production of rescue factors by non-clonogenic tumour cells that may persist in some tumours for considerable periods of time.