Early neoplastic and metastatic mammary tumours of transgenic mice detected by 5-aminolevulinic acid-stimulated protoporphyrin IX accumulation.

A photodynamic technique for human breast cancer detection founded upon the ability of tumour cells to rapidly accumulate the fluorescent product protoporphyrin IX (PpIX) has been applied to transgenic mouse models of mammary tumorigenesis. A major goal of this investigation was to determine whether mouse mammary tumours are reliable models of human disease in terms of PpIX accumulation, for future mechanistic and therapeutic studies. The haeme substrate 5-aminolevulinic acid (5-ALA) (200 mg kg(-1)) was administered to mouse strains that develop mammary tumours of various histological subtypes upon expression of the transgenic oncogenes HRAS, Polyoma Virus middle T antigen, or Simian Virus 40 large T antigen in the mammary gland. Early neoplastic lesions, primary tumours and metastases showed consistent and rapid PpIX accumulation compared to the normal surrounding tissues, as evidenced by red fluorescence (635 nm) when the tumours were directly illuminated with blue light (380-440 nm). Detection of mouse mammary tumours at the stage of ductal carcinoma in situ by red fluorescence emissions suggests that enhanced PpIX synthesis is a good marker for early tumorigenic processes in the mammary gland. We propose the mouse models provide an ideal experimental system for further investigation of the early diagnostic and therapeutic potential of 5-ALA-stimulated PpIX accumulation in human breast cancer patients.

Changes in patterns of acute medical receiving in Scotland 1996 to 2001.

The purpose of this study was to review changes in working practises of physicians and hospitals from 1996 to 2001 in the light of rising medical admissions and published reports into the organisation of acute admissions. Information was gathered by direct discussion with the appropriate lead doctor for each hospitals acute service in February 2001. The results were compared with a previously published study, which recorded the situation as of October 1996. The hospitals which were studied were the twenty seven Scottish hospitals which admit more than 3000 acute medical patients each year. There has been a 25% increase in number of consultants carrying out receiving duties. Nearly all hospitals now have an acute admission unit. Four hospitals have appointed acute care physicians. Triage of appropriate patients to more specialised ward based care has increased. There has been a rise in geriatricians involvement in acute receiving from four to fifteen hospitals. New developments include early discharge for chronic obstructive airway disease, outpatient management of venous thrombosis, discharge planning and streamlining investigation of chest pain. Two hospitals have specific alcohol support services. There continues to be progress and changes within medical and geriatric services over the last five years stimulated by the continuing rise in number of medical admissions.

Homocysteine-dependent alterations in mitochondrial gene expression, function and structure. Homocysteine and H2O2 act synergistically to enhance mitochondrial damage.

Mitochondrial abnormalities have been identified in hepatocytes of patients with hyperhomocysteinemia and in endothelial cells from the aortas of rats with diet-induced hyperhomocysteinemia. However, the mechanism by which homocysteine affects mitochondria is unknown. In this report, homocysteine-induced expression of the mitochondrial electron transport chain gene, cytochrome c oxidase III/ATPase 6,8 (CO3/ATPase 6,8), was identified in a human megakaryocytic cell line DAMI using mRNA differential display. Steady-state mRNA levels of CO3/ATPase 6,8, as well as other mitochondrial transcripts, were increased in DAMI cells by homocysteine in a concentration- and time-dependent manner. Despite an increase in mitochondrial RNA levels and changes in mitochondrial ultrastructure, no effect on either cell growth or mitochondrial respiration rates was observed in DAMI cells exposed to homocysteine at concentrations up to 1 mM. In contrast, 1 mM homocysteine in the presence of Cu2+, which is known to generate H2O2, significantly decreased mitochondrial RNA levels, caused gross morphological changes in mitochondrial ultrastructure, and inhibited both cell growth and mitochondrial respiration rates. However, precursors of cellular glutathione and preexposure to heat shock blocked the decrease in mitochondrial RNA levels caused by homocysteine and Cu2+. The observations that (i) homocysteine and H2O2, but not H2O2 alone, caused a decrease in mitochondrial RNA levels, (ii) intracellular levels of H2O2 were significantly increased in the presence of homocysteine and Cu2+, and (iii) catalase, but not free radical scavengers, prevented a decrease in mitochondrial RNA levels, provide evidence that homocysteine and H2O2 act synergistically to cause mitochondrial damage. Furthermore, our findings suggest that intracellular glutathione and heat shock proteins play a role in protecting mitochondria against the adverse effects elicited by homocysteine and H2O2.

Mitochondrial contributions to cancer cell physiology: redox balance, cell cycle, and drug resistance.

Alterations in the biochemistry of mitochondria have been associated with cell transformation and the acquisition of drug resistance to certain chemotherapeutic agents, suggesting that mitochondria may play a supportive role for the cancer cell phenotype. Mitochondria are multifunctional organelles that contribute to the cellular adenosine triphosphate (ATP) pool and cellular redox balance through the production of reactive oxygen intermediates (ROI). Our laboratory has focused on these mitochondrial functions in the context of cancer cell physiology to evaluate the potential role of mitochondria as controllers of tumour cell proliferation. Low concentrations of ROI have been implicated as messengers in intracellular signal transduction mechanisms; thus an imbalance of ROI production from the mitochondria may support cancer cell growth. In addition, suppression of mitochondrial ATP production can halt cell cycle progression at two energetic checkpoints, suggesting that the use of tumor-selective agents to reduce ATP production may offer a therapeutic target for cancer growth control.

Patterns of acute medical receiving in Scotland.

The study reviews the patterns of acute medical receiving in Scottish hospitals. Physicians from hospitals with an accident and emergency department and more than 3,000 medical discharges per year were questioned on consultant working behaviour, acute bed usage, the presence of triage and type of geriatric liaison service. The situation as of October 1996 in 26 hospitals is described. In six Trusts consultants have time off other duties to help with acute admissions. In five there is consultant responsibility for acute patients for more than 24 hours, up to a week. Six units have a policy of triage to specialty wards. Eighteen of the 26 units have an Acute Admission Unit (AAU). The needs related geriatric service predominates, but many geriatricians now visit the medical AAU daily. Acute medical receiving systems have been stressed by competing demands and the rise in medical admissions. Most medical units in Scotland have developed new ways of working or are looking at adaptations of their receiving systems.

Coping with the inexorable rise in medical admissions: evaluating a radical reorganisation of acute medical care in a Scottish district general hospital.

OBJECTIVE: To describe radical changes in acute medical care in a district general hospital and assess their impact on staff and patients. DESIGN: A before and after comparison of structure, process and outcome indicators in the year preceding and following reorganisation. SETTING: The Adult Medicine Clinical Directorate of the Royal Alexandra Hospital in Paisley, Scotland. SUBJECTS: Staff in the Medical Directorate and a random sample of 400 patients. INTERVENTIONS: The main stimulus for reorganisation was the pressure caused by a relatively steep rise in admissions. In response, the six existing general medical wards were converted into a 38-bed Medical Admissions Unit and five more specialised wards. A new acute receiving rota allowed each consultant to concentrate almost exclusively on acute receiving for one week at a time. RESULTS: The boarding of patients in non-medical wards was eliminated through improved bed management. The needs of patients became better matched to the specialism of their consultant. The cardiologist's share of in-patients with cardiological problems rose from 34% of 2,877 cases to 58% of 3,085 cases (p < 0.001) and the respiratory physicians' share of respiratory in-patients grew from 53% of 1,281 cases to 67% of 1,287 cases (p < 0.001). After the reorganisation, medical staff had significantly fewer concerns about losing track of patients (p < 0.01) or about boarding (p < 0.01), however, concern about 'blocked beds' became greater (p < 0.05). Nurses reported more time for health promotion (p < 0.01) but also a rise in stress (p < 0.05). More patients reported that staff had time to explain their treatment (85/109 (79%) before, 93/105 (89%) after, p < 0.05) and a higher proportion felt ready for discharge (91/108 (84%) before, 99/106 (93%) after, p < 0.05). CONCLUSIONS: Radical reorganisation of medical care in response to rising acute medical admissions is achievable and may lead to improvements in care.

Energetic characteristics of cisplatin resistant ovarian carcinoma cells.

An elevated mitochondrial membrane potential coincides with cisplatin resistance in the 2008, C13* and RH4 ovarian carcinoma cell system. Since the mitochondrial membrane potential is a component of the overall proton motive force which drive mitochondrial ATP production, we evaluated the energetic characteristics of these cells with biochemical and pharmacologic assays. Our data shows that the cisplatin resistant C13* cells have reduced mitochondrial respiratory function and enhanced sensitivity to oligomycin, a specific inhibitor of oxidative phosphorylation, compared to the cisplatin sensitive 2008 parental line. This suggests that the chronic cisplatin exposures used to generate C13* cells debilitated mitochondrial functions. This characteristic, however, seems unrelated to cisplatin resistance since the impairment persist in the RH4 variant despite its returned cisplatin sensitivity. We suggest that mitochondrial membrane potential influences cellular processes distinct from energy production and that these processes are relevant to cisplatin resistance.

Activity of erythrocyte delta-aminolevulinic acid dehydratase in the female cynomolgus monkey (Macaca fascicularis): kinetic analysis in control and lead-exposed animals.

Kinetic analysis of erythrocyte delta-aminolevulinic acid dehydrase (delta-ALAD) from female cynomolgus monkeys revealed differences in pH optimum and Michaelis constants according to their exposure to lead. In vitro incubation of delta-ALAD with 5 mM dithiothreitol (DTT) or 100-200 microM zinc resulted in an enhanced enzyme activity being expressed. These effects were additive. Activation with DTT or zinc resulted in the abolition of pH differences between control and exposed animals and revealed an increased quantity of enzyme in exposed animals. delta-ALAD in control monkeys was observed to be very sensitive to inhibition by lead in vitro with an apparent inhibition constant (Ki) of 0.12 microM. The effect of lead on monkey delta-ALAD enzyme kinetics is similar to that seen with human samples and thus is a useful model for measuring biological response to lead exposure.

Airway responses to deep inspiration in diabetic autonomic neuropathy.

The role of vagal mechanisms in the reversal of pharmacologically-induced bronchoconstriction by deep inspiration is unclear. We examined the effect of lung inflation on methacholine-induced bronchoconstriction in six patients with severe diabetic autonomic neuropathy compared with five patients with diabetes mellitus and normal tests of autonomic function. The effect of deep inspiration on bronchomotor tone was expressed as the ratio of maximal flow rates at 70% of expiratory vital capacity (V30) calculated from complete (V30(c)) and partial (V30(p)) flow-volume curves (V30(c)/V30(p)). In patients with autonomic neuropathy the mean (range) of this ratio was 1.31 (1.19-1.47) and was not significantly different from the control patients with a mean ratio of 1.69 (1.28-2.13). These results suggest that the reversal of methacholine-induced bronchoconstriction by a deep inspiration is not mediated via vagal nerves.

Phase II studies of mitozolomide in melanoma, lung and ovarian cancer.

Seventy-seven patients were treated with oral mitozolomide to assess the activity of this drug in melanoma, lung and ovarian cancer. Partial responses were seen in five of 18 evaluable patients with small cell lung cancer (SCLC) and three of 20 with melanoma. No activity was apparent in non small cell lung or epithelial ovarian cancer. The major toxicity was myelosuppression which necessitated reduction in the initial dosage from 115 to 90 mg/m2. However, even at this dose level, unpredictable WHO grade 4 toxicity occurred in non-pretreated patients. Thrombocytopenia was more common than leucopenia and eight patients required platelet transfusion for spontaneous or tumour-related haemorrhage. Myelotoxicity was considered responsible for two deaths and was a significant contributory factor in a further three. Non-haematological toxicity was minor. Thus, despite demonstrable activity in SCLC and melanoma, unpredictable myelosuppression is likely to preclude further assessment in combination chemotherapy regimes in these tumours.

Effect of house dust mite avoidance measures on adult atopic asthma.

Twenty one adult patients with asthma, with positive skin test responses to the European house dust mite, Dermatophagoides pteronyssinus, were randomly allocated to a control group or to a group applying house dust mite avoidance measures. These included an initial application of liquid nitrogen to mattresses and bedroom carpets to kill the live house dust mite population. Histamine airway responsiveness, symptom scores, peak expiratory flow rates (PEF), and house dust mite numbers were determined during the two week pretrial and eight week trial periods. Nine patients in each group completed the study. By the end of the study there was a significant reduction in live mites in the "avoidance" group but not in the control group. The avoidance group showed a significant improvement in symptom scores measured on a linear analogue scale, in the number of hours each day spent wheezing (mean reduced from 8.6 to 4.5 hours), and in PEF (l/min) both in the morning (from 364 to 388) and in the evening (from 368 to 392). These changes were not found in the control group. The provocative concentration (PC) of histamine causing a 20% fall in FEV1 (PC20FEV1) had increased significantly in the avoidance group at eight weeks (from 0.58 to 2.3 mg/ml), whereas no change was seen in the control group (from 0.93 to 1.21 mg/ml). These results show that house dust mite avoidance, combined with initial killing of the mite by liquid nitrogen, diminishes airway responsiveness and improves asthma symptom control over an eight week period in adult asthmatic patients with house dust mite allergy.

Short duration combination chemotherapy in the treatment of small cell lung cancer.

Ninety five patients (57 with limited disease and 38 with extensive disease) with previously untreated small cell lung cancer were entered into a study of short duration combination chemotherapy with intravenous cyclophosphamide (750 mg/m2) on day 1, adriamycin (40 mg/m2) on day 1, and etoposide VP-16 (100 mg/m2) on days 1, 2, and 3, with the addition on day 10 of methotrexate 50 mg/m2 with folinic acid rescue and vincristine 2 mg. The treatment was repeated on day 22 and only three courses were given. No maintenance chemotherapy was given, though patients with a complete response received radiotherapy (30-40 Gy (3000-4000 rads] to the primary site in most cases. Forty nine patients (86%) with limited disease achieved a response, with 26 (46%) complete remissions. Twenty five patients (66%) with extensive disease had a response, but only eight (21%) had a complete response. Actuarial survival analysis for the whole patient population showed a median survival of 13 months for patients with limited disease and seven months for those with extensive disease. The median survival was 14 months for those patients with limited disease who achieved a complete response, but only 10 months for non-responders. Myelosuppression was the major expression of toxicity. There were three deaths related to treatment and seven patients had febrile episodes during neutropenia that required antibiotics. Mucositis, which was usually mild, occurred in 49% of patients. The primary site was the main site of initial relapse in 56% of the patients who relapsed. Among patients with limited disease who achieved a complete response, relapses at the primary site were less common in those who received radiotherapy (five out of 12) than in those who did not (all eight). The results indicate that this short duration chemotherapy in small cell lung cancer gives response rates and the potential for long term survival similar to those obtained in other series while allowing patients the maximum time free from treatment.

Effect of nedocromil sodium on histamine airway responsiveness in grass-pollen sensitive asthmatics during the pollen season.

We examined the effect of nedocromil sodium on histamine airway responsiveness in twelve grass-pollen sensitive patients during the 1984 pollen season. The study was a randomized double-blind crossover comparison of nedocromil sodium administered by a pressurized aerosol (4 mg b.d.) with placebo. Crossovers were made at 14-day intervals throughout 8 weeks of the grass pollen season. Histamine airway responsiveness was assessed twice before the pollen season and at the end of each 14-day treatment period. Results were expressed as the provocation concentration (PC) producing a 10% fall in FEV1 (PC10 FEV1) and a 40% fall in flow at 30% of the vital capacity (PC40 V30(P]. During the pollen season all patients developed hay fever and seven had symptoms of asthma. The observed lowest values of PC10 FEV1 and PC40 V30(P) during the placebo treatment periods were significantly lower than mean preseasonal values although not significantly lower than theoretical expected values. Geometric means PC10 FEV1 and PC40 V30(P) were significantly higher during nedocromil sodium treatment compared with placebo. These results indicate that nedocromil sodium has a small but statistically significant effect reducing histamine airway responsiveness in grass-pollen sensitive patients during the pollen season.

Inhaled ketotifen in exercise-induced asthma--a negative report.

The effects of 2 concentrations of inhaled ketotifen (0.25 g/l and 0.5 g/l) were compared with saline in 7 extrinsic asthmatics with exercise induced asthma (EIA). Inhaled ketotifen produced bronchodilatation with a significant increase of 15.4% on mean baseline FEV1 at the higher concentration (p less than 0.05). After exercise the mean percentage fall in FEV1 was 38.4% in the saline group, with no significant difference in the ketotifen pretreated groups, although 2 patients did not have EIA after inhalation of either ketotifen concentrations.

The role of VP-16 in the treatment of small-cell lung cancer: studies of the West of Scotland Lung Cancer Group.

Reviews of published studies indicate that the incorporation of VP-16 (Vepesid) into combination chemotherapy for small-cell lung cancer may improve overall response rates from 50% to between 65% and 80%. In addition, high-dose VP-16 may yield a higher response rate than that obtained with conventional doses. The West of Scotland Lung Cancer Group has therefore conducted studies to examine the effects of VP-16 both in a combination regimen as induction therapy and (together with high-dose cyclophosphamide) as late intensification therapy in high dose, aimed at preventing relapse in responding patients. Response to induction treatment improved with the addition of VP-16, compared to earlier studies carried out by the group, yielding an overall response rate of 80% for patients with limited disease and 62% for those with extensive disease. Although induction therapy comprised only three courses (lasting 9 weeks), the median response duration of 9.5 months for complete responders and the median survival of 14 months for complete responders (limited disease) were in keeping with those obtained using more prolonged induction therapy. The intensification therapy with high-dose cyclophosphamide and high-dose VP-16, however, yielded no improvement in overall survival in those responding patients who received it compared with those who did not. Radiotherapy following late-dose intensification prevented local tumor recurrence but appeared to have no effect on overall survival. Resistance to VP-16 and other drugs is a possible deterrent to successful therapy in small-cell lung cancer, and it is suggested that research focus on a possible role for calcium channel blockers in circumventing drug resistance.

High-dose cyclophosphamide and VP 16 as late dosage intensification therapy for small cell carcinoma of lung.

This study investigated the use of late dose intensification therapy (LDIT) with cyclophosphamide (180 mg/kg) and VP 16 (1 g/m2) plus autologous bone marrow rescue in 22 patients with small cell lung cancer (SCLC). These patients were selected from a group of 95 patients who received three courses of a five-drug induction regimen comprising cyclophosphamide (750-1000 mg/m2), adriamycin (40 mg/m2), VP 16 (100 mg/m2) for 3 days, methotrexate (50 mg/m2) and vincristine (2 mg) (CAVMO). There were 16 patients with limited disease, 8 of whom were in complete remission (CR) and 8 in partial remission (PR) after the induction therapy. The other 6 patients had extensive disease; 3 of these achieved CR and 3 PR after induction therapy. Of the 11 patients in PR, 5 responded to LDIT; 3 had a further PR, and 2 CR. Subsequent to LDIT radiotherapy 4000 cGy was given to the primary site in 10 of the 22 patients. Since the start of the study, 19 of the 22 patients have relapsed and died (median survival 11 months), while 3 remain alive and in remission at 11, 11, and 24 months. Comparison of the survival of patients receiving LDIT with that of an equivalent group (with respect to staging and response to induction chemotherapy) of patients who received induction chemotherapy alone showed no significant difference. In this study, LDIT following conventional induction therapy in patients with chemosensitive tumours did not improve survival.

A comparison of the clinical and immunological effects of an alum-precipitated five-grass extract with a conjugated two-grass extract in the desensitization of hay fever.

Thirty-nine patients with pollen hay fever were randomly allocated to receive either an alum-precipitated five-grass extract (Allpyral) or a two-grass conjugated extract (Conjuvac) prior to the 1982 pollen season. Efficacy was assessed by means of symptom scores, drug usage and specific IgE and IgG antibody response. Both nasal and eye symptom scores were significantly higher during the pollen season in those patients receiving Allpyral. Specific IgE and IgG measured after the pollen season showed similar rises in each group. Seven patients showed a marked elevation in specific IgE and nine a marked elevation in specific IgG, but no patient showed both. Those with a high specific IgE level tended to be younger. Symptom scores bore no relation to either specific IgE or IgG antibodies. Side-effects were mainly local and were equal in both groups.