Experimental investigation of geologically produced antineutrinos with KamLAND

The detection of electron antineutrinos produced by natural radioactivity in the Earth could yield important geophysical information. The Kamioka liquid scintillator antineutrino detector (KamLAND) has the sensitivity to detect electron antineutrinos produced by the decay of 238U and 232Th within the Earth. Earth composition models suggest that the radiogenic power from these isotope decays is 16 TW, approximately half of the total measured heat dissipation rate from the Earth. Here we present results from a search for geoneutrinos with KamLAND. Assuming a Th/U mass concentration ratio of 3.9, the 90 per cent confidence interval for the total number of geoneutrinos detected is 4.5 to 54.2. This result is consistent with the central value of 19 predicted by geophysical models. Although our present data have limited statistical power, they nevertheless provide by direct means an upper limit (60 TW) for the radiogenic power of U and Th in the Earth, a quantity that is currently poorly constrained.

Three efflux pumps are required to provide efficient tolerance to toluene in Pseudomonas putida DOT-T1E

In Pseudomonas putida DOT-T1E multidrug efflux pumps of the resistance-nodulation-division family make a major contribution to solvent resistance. Two pumps have been identified: TtgABC, expressed constitutively, and TtgDEF, induced by aromatic hydrocarbons. A double mutant lacking both efflux pumps was able to survive a sudden toluene shock if and only if preinduced with small amounts of toluene supplied via the gas phase. In this article we report the identification and characterization in this strain of a third efflux pump, named TtgGHI. The ttgGHI genes form an operon that is expressed constitutively at high levels from a single promoter. In the presence of toluene the operon is expressed at an even higher level from two promoters, the constitutive one and a previously unreported one that is inducible and that partially overlaps the constitutive promoter. By site-directed mutagenesis we constructed a single ttgH mutant which was shown to be unable to survive sudden 0.3% (vol/vol) toluene shocks regardless of the preculture conditions. The mutation was transferred to single and double mutants to construct mutant strains in which two or all three pumps are knocked out. Survival analysis of induced and noninduced cells revealed that the TtgABC and TtgGHI pumps extruded toluene, styrene, m-xylene, ethylbenzene, and propylbenzene, whereas the TtgDEF pump removed only toluene and styrene. The triple mutant was hypersensitive to toluene, as shown by its inability to grow with toluene supplied via the vapor phase.

A therapeutic benefit from combining normobaric carbogen or oxygen with nicotinamide in fractionated X-ray treatments

The ability of normobaric oxygen and carbogen (95% O2 + 5% CO2) combined with nicotinamide to enhance the radiosensitivity of two rodent adenocarcinomas and of mouse skin and kidneys, using a 10 fraction radiation schedule, was compared with the effect of radiation in air with and without the drug. Tumour response was assayed using local control and regrowth delay, and compared with acute skin reactions, decreased renal 51Cr-EDTA clearance and reduction in haematocrit. Nicotinamide increased the radiation sensitivity of CaNT tumours under all three different oxygen concentrations tested (21, 95 and 100% oxygen). The effect was statistically significant for oxygen and carbogen but not for air; the combination of nicotinamide with carbogen gave the greatest increase in tumour radiosensitivity. Relative to treatments in air without the drug, the enhancement ratios (ER) at the TCD50 level were 1.17, 1.65 and 1.83 for CaNT tumours irradiated in air, oxygen or carbogen and injected with nicotinamide 1 h before each fraction. The ER in CaRH tumours irradiated in carbogen plus the drug was 1.83, which was greater, but statistically not significantly different, to that seen with carbogen alone (ER = 1.68). In skin, relative to air without the drug, the increase in radiosensitivity by nicotinamide was greater in oxygen and carbogen than in air (1.29, 1.36 and 1.08, respectively). The ERs for both assays of renal damage were similar and lower than those in skin: less than or equal to 1.07, less than or equal to 1.13 and less than or equal to 1.16 for irradiations done in air, oxygen and carbogen plus nicotinamide, relative to air alone. A comparison of these results in the tumours and normal tissues showed that a significant therapeutic benefit was obtained with normobaric oxygen and carbogen combined with nicotinamide. This benefit is greater than observed with other radiosensitizers tested so far. Toxic side effects of the treatment are unlikely in a clinical situation, since prolonged administration of nicotinamide is well tolerated in man. The combination of normobaric carbogen with nicotinamide could be an effective method of enhancing tumour radiosensitivity in clinical radiotherapy where hypoxia limits the outcome of treatment.

Myocardial parasite persistence in chronic chagasic patients

The persistence of Trypanosoma cruzi tissue forms was detected in the myocardium of seropositive individuals clinically diagnosed as chronic chagasic patients following endomyocardial biopsies (EMBs) processed by immunohistochemical (peroxidase-anti-peroxidase [PAP] staining) and molecular (polymerase chain reaction [PCR]) techniques. An indirect immunofluorescent technique revealed antigenic deposits in the cardiac tissue in 24 (88.9%) of 27 patients. Persistent T. cruzi amastigotes were detected by PAP staining in the myocardium of 22 (84.6%) of 26 patients. This finding was confirmed with a PCR assay specific for T. cruzi in 21 (91.3%) of 23 biopsy specimens from the same patients. Statistical analysis revealed substantial agreement between PCR and PAP techniques (k = 0.68) and the PCR and any serologic test (k = 0.77). The histopathologic study of EMB specimens from these patients revealed necrosis, inflammatory infiltrates, and fibrosis, and made it possible to detect heart abnormalities not detected by electrocardiogram and/or cineventriculogram. These indications of myocarditis were supported by the detection of T. cruzi amastigotes by the PAP technique or its genome by PCR. They suggest that although the number of parasites is low in patients with chronic Chagas' disease, their potential for heart damage may be comparable with those present during the acute phase. The urgent necessity for testing new drugs with long-term effects on T. cruzi is discussed in the context of the present results.

Synergism between Phyllobacterium sp. (N(2)-fixer) and Bacillus licheniformis (P-solubilizer), both from a semiarid mangrove rhizosphere

Mangrove seedlings were treated with a mixture of two bacterial species, the slow-growing, N(2)-fixing bacterium Phyllobacterium sp. and the fast-growing, phosphate-solubilizing bacterium Bacillus licheniformis, both isolated from the rhizosphere from black, white, and red mangroves of a semiarid zone. Nitrogen fixation and phosphate solubilization increased when the mixture was used compared to the effects observed when adding individual cultures, notwithstanding that there was no increase in bacterial multiplication under these conditions. Inoculation of black mangrove seedlings in artificial seawater showed the mixture performed somewhat better than inoculation of the individual bacterium; more leaves were developed and higher levels of (15)N were incorporated into the leaves, although the total nitrogen level decreased. This study demonstrates that interactions between individual components of the rhizosphere of mangroves should be considered when evaluating these bacteria as plant growth promoters.

Screening for antimicrobial activity of crude drug extracts and pure natural products from Mexican medicinal plants

Preliminary antimicrobial screening against Candida albicans and selected Gram-positive and Gram-negative bacteria of methanol extracts prepared from eight Mexican medicinal plants, noted for their antiseptic properties, was conducted. The significant activity exhibited for extracts of Ratibida latipalearis, Teloxys graveolens, Dodonaea viscosa, Hyptis albida, H. pectinata, H. Suaveolens and H. verticillata tends to support their traditional use as anti-infective agents. Only the extract of Hintonia latiflora was inactive. The antimicrobial activities of 44 pure natural compounds and two derivatives were determined. Of these, only 23 compounds were effective in inhibiting the growth of the tested organisms (MIC less than or equal to 100 micrograms/ml).

CHART (continuous, hyperfractionated, accelerated radiotherapy): a tale of two disciplines

Zingiberaceae rhizomes commonly used in the Malaysian traditional medicine were screened for anti-tumour promoter activity using the short-term assay of inhibition of 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced Epstein-Barr virus early antigen (EBV-EA) in Raji cells. The inhibition of TPA-induced EBV-EA was detected using the indirect immunofluorescence assay (IFA) and Western blot technique. The indirect IFA detected the expression/inhibition of EBV-EA-D (diffused EA antigen), whereas the Western blot technique detected the expression/inhibition of both EBV-EA-D and EA-R (restricted EA antigen). Seven rhizomes were found to possess inhibitory activity towards EBV activation, induced by TPA; they are: Curcuma domestica, C. xanthorrhiza, Kaempferia galanga, Zingiber cassumunar, Z. officinale, Z. officinale (red variety), and Z. zerumbet. A cytotoxicity assay was carried out to determine the toxicity of the Zingiberaceae rhizome extracts. The rhizome extracts that exhibited EBV activation inhibitory activity had no cytotoxicity effect in Raji cells. Therefore, the present study shows that several Zingiberaceae species used in Malaysian traditional medicine contain naturally occurring non-toxic compounds that inhibit the EBV activation, which, if further investigated, could contribute in the development of cancer prevention methods at the tumour-promoting stage. © 1999 Cancer Research Campaign

Regulation of endothelial nitric oxide synthase expression by albumin-derived advanced glycosylation end products

We examined whether albumin-derived advanced glycosylation end products (AGEs) downregulate the expression of endothelial nitric oxide synthase (NOS). Significant reductions in NOS activity and cGMP levels in bovine aortic endothelial cells were observed when exposed to different concentrations of albumin-derived AGEs. Western and Northern blot analyses showed significant decreases at the protein and transcript levels. Both reductions became evident after 24 hours of exposure. Nuclear run-on assays showed that AGE-BSA did not modify the transcription rate of the NOS III gene; however, AGE-BSA treatment markedly reduced the half-life of NOS III mRNA. In addition, AGE-treated endothelial cells displayed significant reduction on their antiplatelet properties. These results indicate that NOS expression is reduced by AGEs by increasing the rate of mRNA degradation and may be relevant to the impairment of some endothelial functions observed in diabetes and aging. The full text of this article is available at http://www.circresaha.org.

Treatment of Trypanosoma cruzi-infected children with nifurtimox: a 3 year follow-up by PCR

Patients suffering from Chagas' disease, as determined by positive serological results, were tested for further evidence of Trypanosoma cruzi infection by xenodiagnosis and PCR. The patients included 67 children aged from 0 to 10 years and 75 adults. All children were positive by PCR on their pre-therapy sample, while only 69% of the seropositive adults and none of the 78 seronegative control adults were PCR positive. Xenodiagnosis was positive in 79% of the children, but only in 21% of the adults. A group of 66 children was treated with nifurtimox, and followed up every 3 months during the first year and every 6 months during the second and third year post-therapy, by PCR, xenodiagnosis and serology. We concluded that PCR was the most effective test to monitor children for 3 years post-chemotherapy, when all the cases converted from positive to negative. Conventional serology, however, remained positive after that period in most cases. In contrast, conversion to negative xenodiagnosis occurred very early after treatment.

Tracheal sleeve pneumonectomy for bronchogenic carcinoma: report of 55 cases

From 1966 to 1986, a total of 55 patients underwent a tracheal sleeve pneumonectomy (53 right and 2 left) for bronchogenic carcinoma. Preoperative radiotherapy was given in only 5 patients. The overall operative death rate was 10.9%, but no patient has died since 1975 (32 survivors). Seven patients had a postoperative empyema (12.7%); 4 of these patients had a bronchopleural fistula. Twenty-five patients had postoperative radiotherapy, 5 of whom also had chemotherapy. The actuarial survival rate, after exclusion of the 6 operative deaths, was 38% at 3 years and 23% at 5 years. Survival was correlated to regional lymph node involvement. The actuarial survival rate among patients with tumoral spread to bronchial lymph nodes was 43% at 3 years. Among the 13 patients with only subcarinal involvement, the actuarial survival rate was 34% at 3 years. None of the 8 patients with paratracheal lymph node involvement survived more than 30 months. These results indicate that tracheal sleeve pneumonectomy for bronchogenic carcinoma with extension to the carina is now fully justified considering the low operative mortality and the good results observed when lateral tracheal lymph nodes were not involved.

Vasoactive and antioxidant activities of plants used in Mexican traditional medicine for the treatment of cardiovascular diseases

This study demonstrated that the aqueous extracts of plants employed in Mexican traditional medicine for the treatment of cardiovascular diseases are able to modify the tone of arterial smooth muscle. Agastache mexicana (Kunth) Lint & Epling (Labiatae), Chenopodium murale L. (Chenopodiaceae), Chirantodendron pentadactylon Larreat (Sterculiaceae), Dracocephalum moldavica L. (Labiatae), Psittacanthus calyculatus G. Don (Loranthaceae), Prunus serotina ssp. capuli (Cav. ex Spreng) McVaugh (Rosaceae), and Sechium edule Sw. (Cucurbitaceae) contain secondary metabolites that promote vascular relaxation and display antioxidant activities. As expected, their antioxidant effects showed a significant correlation with the polyphenolics content. However, a lower correlation was found between the antioxidant activity and the maximum vasodilatory effect, suggesting that the vasodilatation elicited by the plant extracts could be only partly attributed to their antioxidant properties. The extract of P. calyculatus, which displayed a maximum vasorelaxant effect that was higher than that of acetylcholine, induced endothelium-dependent vasodilatation. Futhermore, the vasorelaxant response to the P. calyculatus extract was reduced after adding an inhibitor of soluble guanylate cyclase activity, providing evidence that the NO/cGMP pathway is involved. On the other hand, the extracts of Bocconia frutescens L. (Papaveraceae), Magnolia grandiflora L. (Magnoliaceae), and Solanum rostratum Dunal (Solanaceae) induced concentration-dependent contraction of rat aortic rings, suggesting that these plants have potential health benefits for the treatment of ailments such as venous insufficiency. The pharmacological activities of the extracts studied provide scientific support for their ethnomedical use.

Pharmacokinetics of nicotinamide and its effect on blood pressure, pulse and body temperature in normal human volunteers

The pharmacokinetics of nicotinamide were studied in four human volunteers after oral doses of 1-6 g. Plasma concentrations and clearance rates of the vitamin were found to be dose-dependent, with a half-life of approximately 7-9 h for the two highest doses administered (4 and 6 g), approximately 4 h with 2 g and approximately 1.5 h with a 1-g dose. Peak concentrations ranged from 0.7 to 1.1 mumol.ml-1 after a 6-g dose. The time to reach peak plasma concentration was dose independent with a broad range from 0.73 to 3 h. In this study, nicotinamide had no detectable effect on blood pressure, pulse or body temperature.

Measurement of neutrino oscillation with KamLAND: evidence of spectral distortion

We present results of a study of neutrino oscillation based on a 766 ton/year exposure of KamLAND to reactor antineutrinos. We observe 258 nu (e) candidate events with energies above 3.4 MeV compared to 365.2+/-23.7 events expected in the absence of neutrino oscillation. Accounting for 17.8+/-7.3 expected background events, the statistical significance for reactor nu (e) disappearance is 99.998%. The observed energy spectrum disagrees with the expected spectral shape in the absence of neutrino oscillation at 99.6% significance and prefers the distortion expected from nu (e) oscillation effects. A two-neutrino oscillation analysis of the KamLAND data gives Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2). A global analysis of data from KamLAND and solar-neutrino experiments yields Deltam(2)=7.9(+0.6)(-0.5)x10(-5) eV(2) and tan((2)theta=0.40(+0.10)(-0.07), the most precise determination to date.

[Loxoscelism in Chile. Epidemiologic, clinical and experimental studies]

A panoramic sight of epidemiological, clinical and experimental studies, referring to Loxosceles laeta and loxoscelism, carried out in 1955-1988, in Santiago, Chile is presented. Two-hundred and sixteen cases of loxoscelism were studied. The most relevant features were: 84.3% corresponded to cutaneous loxoscelism (CL) and 15.7% to viscerocutaneous loxoscelism (VCL); 73.6% occurred in hot season; in 86.6% of cases the accident happened in the house, particularly in bedrooms, while the people were sleeping or dressing. The spider was seen in 60.2% of cases and identified in the laboratory as L. laeta in 10.6% of all cases. The sites more frequently bitten were the limbs with 67.6%; a burning-stinging was the most frequent initial symptom. Pain, edema and livedoid plaque, which developed later into a necrotic eschar, were the predominant local manifestations. In VCL, hematuria and hemoglobinuria were constant, while jaundice, fever and sensorial involvement were present in most of the cases. CL patients were parenterally treated with antihistaminic drugs or corticoids, while VCL ones were treated with corticoids by injection. The condition of patients in the last follow up was: complete cure in 75.5%, cure with a scarfed sequela in 8.3%, death in 3.7% (all VCL) and abandonment in 12.5%. Additionally, a series of experimental studies, both in vivo and in vitro, has been performed in order to clarify basic aspects on L. laeta venom and the treatment of loxoscelism.

ARCON: accelerated radiotherapy with carbogen and nicotinamide in head and neck squamous cell carcinomas. The experience of the Co-operative group of radiotherapy of the european organization for research and treatment of cancer (EORTC)

BACKGROUND

Since there is increasing evidence that both acute (perfusion-limited) and chronic (diffusion-limited) hypoxia, and tumor repopulation may prejudice the outcome of radiotherapy, the combination of carbogen (95% oxygen-5% carbon dioxide) and nicotinamide with accelerated radiotherapy (ARCON) should reduce the impact of these factors of radioresistance.

AIM

This clinical study was aimed at determining the feasibility, as well as the qualitative and quantitative toxic effects of a therapeutic approach based on ARCON, and assessing the tumor response rates that can be achieved with this regime in patients with locally advanced tumors of the head and neck.

METHODS

A phase I/II study conducted between 1993 and 1996 by the Co-operative Group of Radiotherapy of the EORTC included three consecutive steps: accelerated fractionation (AF) combined with carbogen (11 analyzable patients), AF combined with the daily administration of nicotinamide (n=10), and AF with both carbogen and nicotinamide (n=17). Radiotherapy was based on an accelerated regime (72 Gy in 5.5 weeks). Nicotinamide was delivered 90 min before the first irradiation session, at a daily dose of 6 g. Carbogen breathing started 5 min before irradiation and lasted throughout the entire radiotherapy sessions.

RESULTS

No significant difference in loco-regional toxicity was found among the three study steps, when carbogen and nicotinamide, either alone or in combination, were combined with AF. The feasibility of the ARCON protocol, as proposed in the present EORTC study, appears to be significantly impaired when nicotinamide is added, at a daily dose of 6 g, to AF and carbogen, in an unselected group of patients. More than 20% of patients experienced grade 2 or 3 emesis. It also demonstrates, in unselected groups of patients, no significant difference in tumor response and local control when carbogen and nicotinamide, either alone or in combination, are added to accelerated radiotherapy. The percentages of objective response at 2 months were 81, 70 and 87%, respectively.

CONCLUSION

Future ARCON trials should target selected head and neck tumor localizations and stages, and a lower nicotinamide dose is needed to reduce severe upper gastro-intestinal toxicity.

The influence of dose per fraction on repair kinetics

The use of multiple fractions per day (MFD) in radiotherapy requires information about the rate of repair of radiation injury. It is important to know the minimum interval between fractions necessary for maximum sparing of normal tissue damage, whether rate of repair is dependent on the size of dose per fraction and if it is different in early and late responding tissues and in tumours. To address these questions, the rate of repair between radiation dose fractions was measured in mouse skin (acute damage), mouse kidney (late damage) and a mouse tumour (carcinoma NT). Skin and kidney measurements were made using multiple split doses of X-rays, followed by a neutron top-up. For skin, faster recovery was obtained with 4.4 Gy fractions (t1/2 = 1.29 +/- 0.35 h, 95% CL) than with 10.5 Gy fractions (t1/2 = 3.46 +/- 0.88 h). In contrast, kidney showed slower recovery at a low dose per fraction of 2 Gy (t1/2 = 1.69 +/- 0.39 h) than at a higher dose of 7 Gy per fraction (t1/2 = 0.92 +/- 0.1 h). These data show that repair rate is dependent on the size of dose per fraction, but not in a simple way. T1/2 values now available for many different tissues generally lie in the range of 1-2 h, and are not correlated with proliferation status or early versus late response to treatment. At the doses used currently in clinical MFD treatments, these data indicate that damage in almost all normal tissues would increase if interfraction intervals less than 6 h were used.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Chagas' disease in western Venezuela: a clinical, seroparasitologic, and epidemiologic study

A clinical, parasitologic, and serologic study carried out between 1988 and 1996 on 59 acute-phase patients in areas of western Venezuela where Chagas' disease is endemic showed 19 symptomatic patterns or groups of symptoms appearing in combination with different frequencies. The symptomatic pattern with the highest frequency was that showing simultaneously fever, myalgia, headache, and Romaña's sign, which was detected in 20% of the acute-phase patients. Asymptomatic individuals and patients with fever as the only sign of the disease made up 15% and 11.9% of the total acute cases, respectively. Statistical correlation analysis revealed that xenodiagnosis and hemoculture were the most reliable and concordant of the five parasitologic methods used; these two methods also showed the highest proportions in detecting any clinical symptomatic pattern in acute-phase patients. A similar high reliability and concordance was obtained with a direct agglutination test, an indirect immunofluorescent antibody test, and an ELISA as serologic tests, which also showed a higher proportion of positive detection of clinical patterns than parasitologic methods (P < 0.001). It is recommended that individuals coming from endemic areas showing mild and/or severe clinical manifestations should be suspected of being in contact or having been in contact with Trypanosoma cruzi, be referred for parasitologic and serologic evaluations to confirm the presumptive clinical diagnosis of acute Chagas' disease, and start specific treatment. The epidemiologic implications of the present findings are discussed and the use of similar methodology to evaluate other areas where Chagas' disease is endemic is suggested.

Carbogen and nicotinamide as radiosensitizers in a murine mammary carcinoma using conventional and accelerated radiotherapy

PURPOSE

To compare the radiosensitivity of mouse tumors treated in air with conventional and accelerated radiotherapy with that of tumors treated in carbogen alone or carbogen combined with nicotinamide.

METHODS AND MATERIALS

CaNT mammary tumors were irradiated with either 30 x-ray fractions in 6 weeks or 40 fractions in 26 days in air, carbogen alone, or carbogen combined with 120 mg/kg of nicotinamide (NAM), the latter given intraperitonealy 30 min before each fraction. The response to treatment was assessed using local control, weight loss, and metastasis-free survival.

RESULTS

Both carbogen and carbogen plus nicotinamide significantly increased tumor radiosensitivity; enhancement ratios (ERs) in the 6-week regimen were similar to those seen in the accelerated schedule. The majority of the effect was achieved by carbogen alone but the addition of NAM further enhanced tumor radiosensitization (ERs of 1.5 and 1.4 for carbogen in the conventional and accelerated schedule, respectively, were significantly lower than ERs of 1.7 and 1.6 obtained with carbogen plus nicotinamide; p < or = 0.005). Treatment protraction significantly increased radioresistance, especially when tumors were treated under air. An extra 1.5 Gy per day was required in air to counterbalance proliferation; in carbogen alone and carbogen plus nicotinamide a dose loss of 0.9 and 0.6 Gy per day was observed, respectively. Compared with treatments in air alone delivered in 6 weeks, acceleration of treatment combined with carbogen and nicotinamide gave the greatest increase in tumor radiosensitization (ER = 1.9). No toxic side effects and no detrimental changes in body weight were encountered when the sensitizers were administered 30 times (one fraction per day) or 40 times (two fractions per day). In both regimens, the incidence of metastases in mice treated with carbogen or carbogen plus nicotinamide was similar to that seen in animals treated in air. There was, however, a nonsignificant trend of a higher proportion of mice with metastasis in the accelerated schedule compared with the 6-week schedule.

CONCLUSIONS

In both conventional and accelerated experimental radiotherapy, carbogen alone or combined with a small clinically relevant dose of NAM were well tolerated, achieved large and significant increases in radiosensitization, and did not affect the incidence of metastases. The sparing of damage, resulting from extending the overall treatment time, was less when the sensitizers were administered than when irradiations were performed in air. The study suggests that clinical radiotherapy regimens, which aim to reduce hypoxic and/or tumor clonogen proliferation, would benefit from the use of carbogen, especially if the gas is combined with nicotinamide and treatment acceleration.

Experience with dose escalation using CHARTWEL (continuous hyperfractionated accelerated radiotherapy weekend less) in non-small-cell lung cancer

Results from the multicentre randomized trial of CHART (continuous, hyperfractionated, accelerated radiotherapy) in non-small-cell lung cancer (NSCLC) showed a significant increase in survival (P=0.004) compared with conventional radiotherapy and a therapeutic benefit relative to late radiation-induced morbidity. However, 60% of patients died because of failure to control locoregional disease. These findings have stimulated interest in assessing the feasibility of dose escalation using a modified CHART schedule. Acute and late morbidity with a CHARTWEL (CHART WeekEnd Less) schedule of 54 Gy in 16 days was compared with that observed with 60 Gy in 18 days in patients with locally advanced NSCLC. The incidence and severity of dysphagia and of analgesia were scored using a semiquantitative clinical scale. Late radiation-induced morbidity, namely pulmonary, spinal cord and oesophageal strictures, were monitored using clinical and/or radiological criteria. Acute dysphagia and the analgesia required to control the symptoms were more severe and lasted longer in patients treated with CHARTWEL 60 Gy (P< or = 0.02). However, at 12 weeks, oesophagitis was similar to that seen with 54 Gy and did not lead to consequential damage. Early radiation pneumonitis was not increased but, after 6 months, there was a higher incidence of mild pulmonary toxicity compared with CHARTWEL 54 Gy. No cases of radiation myelitis, oesophageal strictures or of grade 2 or 3 lung morbidity have been encountered. CHARTWEL 60 Gy resulted in an enhancement of oesophagitis and grade 1 lung toxicity compared with CHARTWEL 54 Gy. These were of no clinical significance, but may be important if CHARTWEL is used with concomitant chemotherapy. These results provide a basis for further dose escalation or the introduction of concurrent chemotherapy.

Adrenal rest tumor of the liver causing Cushing's syndrome: treatment with ketoconazole preceding an apparent surgical cure

Ketoconazole, an imidazole derivative known to inhibit cytochrome P450-dependent adrenal enzymes was given to a patient with a functioning adrenal rest tumor of the liver in preparation for surgery. The drug was administered in a stepwise manner for 42 days starting with 400 mg and reaching 1 g the last 4 weeks of the trial. Clear clinical improvement was evident early in the trial and was associated with evidence of amelioration of her hypercortisolism and striking changes in serum and urinary levels of steroid hormones and metabolites. Sex steroids in serum and urine fell dramatically from the first day to the end of the trial. Urinary 17-ketosteroid excretion fell from a basal average of 139 mg/24 h to near normal levels within a week of therapy; serum testosterone fell from a basal level of 2.4 to 0.18 ng/ml; serum 17 beta-estradiol fell likewise from 1096 to 150 pg/ml. In contrast, cortisol levels in serum and urine increased in the first 2 weeks of the trial and subsequently fell to values below the basal levels. Similarly, serum 17 alpha-OH-progesterone levels increased 63% above the basal levels by day 6 of the trial and declined afterwards. Nine months after successful tumor resection the patient is apparently cured as judged by steroid hormone levels and physical appearance. We conclude that ketoconazole was effective in blocking tumoral steroidogenesis which resulted in clinical benefit.

Carbogen and nicotinamide in the treatment of bladder cancer with radical radiotherapy

Carbogen and nicotinamide have been evaluated in a phase II study as hypoxia-modifying agents during radical radiotherapy for bladder cancer using a standard daily 20-fraction schedule. Three groups of patients have received (a) nicotinamide alone, given orally in a dose of 80 mg kg(-1) daily with 52.5 Gy in 20 fractions over 4 weeks, (b) carbogen alone, with 50 Gy in 20 fractions over 4 weeks, and (c) carbogen and nicotinamide, with 50-52.5 Gy in 20 fractions over 4 weeks. Ten patients were treated in each group. All patients completed carbogen and radiotherapy as prescribed, but only 45% completed daily nicotinamide over the 4-week treatment period. The end points of this study were acute bowel and bladder morbidity and local control at cystoscopy 6 months after treatment. An expected level of acute bowel and bladder morbidity was seen that reverted to normal in most patients by 12 weeks with no difference between the three treatment groups. Complete response rates at 6 months were seven out of ten (100%) in the nicotinamide alone group, nine out of ten (90%) in the carbogen alone group and seven out of ten (70%) in the carbogen and nicotinamide group. It is concluded that carbogen and nicotinamide may improve the results of daily fractionated radiotherapy in bladder cancer and that further evaluation is required.

Glutathione depletion in tissues after administration of buthionine sulphoximine

Buthionine sulphoximine (BSO) an inhibitor of glutathione (GSH) biosynthesis, was administered to mice in single and repeated doses of 0.5, 1 and 5 mmol kg-1 (i.p.). The resultant pattern of GSH depletion was studied in liver, kidney, skeletal muscle and three types of murine tumor. Liver and kidney exhibited a rapid depletion to GSH levels of ca. 20% of controls after single doses of 1-5 mmol kg-1 BSO. Muscle was depleted to a similar level, but at a slower rate after a single dose. All three tumors required repeated administration of BSO over several days to obtain a similar degree of depletion to that shown in the other tissues.