The protein kinase C inhibitor CGP41251 suppresses cytokine release and extracellular signal-regulated kinase 2 expression in cancer patients

Components of cell signaling pathways provide important targets for anticancer drugs. Protein kinase C (PKC) is a serine/threonine-specific kinase that regulates cell growth and differentiation. It is also implicated in tumor promotion. The staurosporine analogue CGP41251 is a PKC inhibitor, and it is currently in a Phase I clinical trial for treatment of advanced cancer. However, it is difficult to define its biological activity. We have used two approaches to measure the in vivo biological response to CGP41251: (a) sequential whole blood samples were taken from 27 patients before and during treatment and incubated with mitogen (PHA), and cytokine [tumor necrosis factor (TNF)-alpha and interleukin (IL)-6] release was measured ex vivo; and (b) peripheral blood lymphocytes were isolated from seven of these patients, and the levels of extracellular signal-regulated kinase 2 were measured by Western blotting. Response to PHA was significantly lowered during treatment (P < 0.001 for TNF-alpha production; P < 0.03 for IL-6). This was most evident at 7 and 28 days after the start of treatment in patients receiving higher doses (150-300 mg/day; P = 0.002 and P = 0.02, respectively, for TNF-alpha and P = 0.001 and P = 0.003, respectively, for IL-6 release). Whole blood cytokine production returned to pretreatment levels after drug administration ceased. The levels of extracellular signal-regulated kinase 2 were reduced by 50-97% during treatment in all seven patients tested. These results show for the first time that a PKC inhibitor can block in vivo signaling pathways in cancer patients. The assays we describe complement toxicity studies in selecting relevant doses for Phase II trial of novel agents, particularly when biological activity occurs at doses below those that cause obvious side effects.

Neonatal examination and screening trial (NEST): a randomised, controlled, switchback trial of alternative policies for low risk infants

OBJECTIVE

To evaluate the effectiveness of one rather than two hospital neonatal examinations in detection of abnormalities.

DESIGN

Randomised controlled switchback trial.

SETTING

Postnatal wards in a teaching hospital in north east Scotland.

PARTICIPANTS

All infants delivered at the hospital between March 1993 and February 1995.

INTERVENTION

A policy of one neonatal screening examination compared with a policy of two.

MAIN OUTCOME MEASURES

Congenital conditions diagnosed in hospital; results of community health assessments at 8 weeks and 8 months; outpatient referrals; inpatient admissions; use of general practioner services; focused analysis of outcomes for suspected hip and heart abnormalities.

RESULTS

4835 babies were allocated to receive one screening examination (one screen policy) and 4877 to receive two (two screen policy). More congenital conditions were suspected at discharge among babies examined twice (9.9 v 8.3 diagnoses per 100 babies; 95% confidence interval for difference 0.3 to 2.7). There was no overall significant difference between the groups in use of community, outpatient, or inpatient resources or in health care received. Although more babies who were examined twice attended orthopaedic outpatient clinics (340 (7%) v 289 (6%)), particularly for suspected congenital dislocation of the hip (176 (3.6/100 babies) v 137 (2.8/100 babies); difference -0.8; -1.5 to 0.1), there was no significant difference in the number of babies who required active management (12 (0.2%) v 15 (0.3%)).

CONCLUSIONS

Despite more suspected abnormalities, there was no evidence of net health gain from a policy of two hospital neonatal examinations. Adoption of a single examination policy would save resources both during the postnatal hospital stay and through fewer outpatient consultations.

Elemental composition of human milk from mothers of premature and full-term infants during the first 3 months of lactation

To examine longitudinal and gestational effects of mineral content in human milk, we analyzed human milk from lactating mothers of premature (PRT, n = 24, < 2000 g birth weight, < 37 wk gestation) and full-term (FT, n = 19, > 2500 g, 39-41 wk gestation), living in Newfoundland, Canada. Samples were collected once a week for 8 wk with one final sample collected at 3 mo. Milk samples collected in acid-washed containers were wet ashed with concentrated HNO3, and barium, cadmium, calcium, cesium, cobalt, copper, cerium, lanthanum, magnesium, manganese, molybdenum, nickel, lead, rubidium, tin, strontium, and zinc were measured using inductively coupled plasma-mass spectrometry. Data were analyzed using standard multiple-regression procedures with correlated data analyses to take account of the relationship between successive weeks. Results indicated lower Ca and Pb in PRT milk. Calcium was the only nutritionally significant element to differ between groups. Molybdenum in both PRT and FT milk showed a definite decrease with time, suggesting that the Mo content in milk is homeostatically regulated. However, Ce, La, Ba, and Sn did not display any pattern indicative of biological regulation and potential human requirement.

Phase I/pharmacokinetic study of the topoisomerase I inhibitor GG211 administered as a 21-day continuous infusion

BACKGROUND

Preclinical results support a prolonged schedule of administration for topoisomerase I inhibitors, and we have previously demonstrated the safety and activity of the novel water-soluble topoisomerase I inhibitor GG211 when given as a 72-hour continuous infusion to cancer patients.

PATIENTS AND METHODS

In a three-center international phase I trial, 38 patients received GG211 doses from 0.3 to 0.5 mg/m2/day by continuous intravenous infusions for seven, 14, and 21 days. Patients' median performance status was 1; nearly half had colorectal cancer, and 35 patients had prior chemotherapy.

RESULTS

The first patient cohort received 0.3 mg/m2/day for seven days with no significant toxicities. Subsequent cohorts received continuous infusions for 14 and 21 days at this dose level with only mild myelosuppression noted. Dose-escalation on the 21-day schedule was then performed. No dose-limiting toxicity occurred at the 0.4 mg/m2/day dose level. Thrombocytopenia was dose-limiting with 0.5 mg/m2/day dosing but was not cumulative. Other grade 3 4 toxicities included neutropenia, nausea, vomiting, diarrhea, and fatigue. Partial responses occurred with 21-day infusion in two patients with breast and ovarian cancer at the 0.3 and 0.4 mg/m2/day dose levels, respectively. Mean GG211 lactone Css ranged from 0.17 to 0.64 ng/ml.

CONCLUSION

The maximum tolerated dose of GG211 administered as a 21-day continuous infusion is 0.4 mg/m2/day with antitumor activity noted at tolerable doses.

AIDS diagnoses at higher CD4 counts in Australia following the introduction of highly active antiretroviral treatment

OBJECTIVES

To assess whether AIDS cases in Australia have been diagnosed at higher CD4 counts since the widespread availability of highly active antiretroviral treatment (HAART) in mid-1996.

METHODS

Data on the CD4 count at AIDS diagnosis for AIDS cases diagnosed between 1 January 1992 and 31 December 1997, and reported to the National AIDS Registry in Australia by 31 March 1998, were analysed. The median CD4 count at AIDS diagnosis, and the proportions of AIDS diagnoses with a CD4 count above 100 cells/microl, and above 200 cells/microl, were calculated by the year of diagnosis, both for all AIDS-defining illnesses, and for each illness separately. Analyses were also stratified by the time interval between HIV and AIDS diagnoses (less than or equal to, or more than, 3 months) because people diagnosed with HIV close to the diagnosis of AIDS would generally not have received any antiretroviral treatment before the diagnosis of AIDS, and so no trends in CD4 counts at the diagnosis of AIDS would be expected in this group.

RESULTS

There was an increase in CD4 count at AIDS diagnosis in 1996 and 1997, although this increase was only apparent for AIDS-defining illnesses other than Pneumocystis carinii pneumonia (PCP), and was limited to AIDS cases diagnosed with HIV more than 3 months before AIDS. In cases of AIDS other than PCP, and diagnosed with HIV more than 3 months before AIDS, the median CD4 count increased from 50 cells/microl in 1995 to 80 cells/microl in 1996 and 134 cells/microl in 1997.

CONCLUSIONS

There has been an increase in the CD4 count at AIDS diagnosis for most AIDS-defining illnesses in Australia coincident with the widespread availability of HAART.

Efficacy and safety of an over-the-counter transdermal nicotine patch as an aid for smoking cessation

OBJECTIVE

To evaluate the efficacy and safety of a transdermal nicotine patch as an aid for smoking cessation in an over-the-counter setting.

DESIGN

Multicenter, double-blind, randomized, placebo-controlled trial of 6-week duration with 18 weeks of follow-up.

SETTING

Four shopping mall precincts.

PARTICIPANTS

The randomized sample consisted of 802 adults (mean age, 39 years) and was 89% white and 54% female. A smoking history of at least 20 cigarettes per day for 1 year and a score of 5 (on a 10-point scale) on a motivational assessment questionnaire were required for enrollment. Poststudy follow-up was limited to those who had quit smoking at the end of 6 weeks.

INTERVENTION

Nicotine patches were provided at the shopping mall. Guidance consisted only of package instructions and a smoking cessation self-help booklet.

MAIN OUTCOME MEASURES

Quit rates were defined as total abstinence from smoking for 4 consecutive weeks (treatment weeks 3-6), point prevalence smoking status at week 6, or nonsmoker at week 6 and week 24 (6-month postquit date). Smoking status was assessed by diaries, and verification for the first 2 quit rates was obtained by confirmation of carbon monoxide of 8 ppm or less in expired breath. Safety was evaluated by self-reported adverse events.

RESULTS

Quit rate was 12% for the active treatment group and 5.5% for the placebo group, based on total abstinence for 4 consecutive weeks (P = .001) compared with quit rates of 19.5% and 7.5% for active treatment and placebo groups, respectively, based on point prevalence data at week 6. At 24 weeks, 8.2% of nonsmokers in the active treatment group and 4.0% in the placebo group remained nonsmokers. At least 1 adverse event was reported by 57% receiving the nicotine patch and 39% receiving placebo (P<.001).

CONCLUSIONS

When the nicotine patch was used in an over-the-counter setting, quit rates were comparable to those reported for medical settings. A 2:1 quit rate advantage was achieved at week 6 and was maintained at 24 weeks.

Torsion of an intra-abdominal testicle in a neonate. Case report and review of the literature

The thirty-ninth reported case of torsion of an intra-abdominal testicle is described in a neonate. The gonad was excised as is recommended because of the high incidence of malignancy (60% of 37 cases). Torsion of an intra-abdominal testicle should be considered where an abdominal mass with calcification is found in an infant with undescended testis. Ultrasonography improves the diagnostic accuracy in infants because of the cystic nature of these masses in this age group.

Factors to consider while treatment planning dental implants in the partially edentulous patient

Although short-term studies of dental implants in the partially edentulous patient appear very promising, multicenter long-term studies are not yet available. Since the differences between dental implants and teeth are significant, treatment planning for the partially edentulous patient is more difficult. This paper will discuss important areas to be examined in treatment planning the partially edentulous patient.

Setting air quality standards for carcinogens: an alternative to mathematical quantitative risk assessment-discussion paper

It has been accepted in many countries that the regulation of ambient air quality should involve the use of health-based air quality standards. Setting standards for air pollutants which are genotoxic carcinogens presents difficult problems to the regulator, in that the prediction of the effects on health of low levels of exposure is suspected to be inaccurate, and is not currently amenable to either experimental or epidemiological verification. In some countries, techniques of mathematical quantitative risk assessment have been adopted to calculate acceptable levels of exposure to, or the unit risk factors for, genotoxic carcinogens. We regard these approaches as unsatisfactory. An alternative approach, based upon a number of argued premises, a strategy which identifies decision points and the cautious application of uncertainty factors, is described.

Community participation within an Irish Health Board area

This article gives a brief analysis of the concept of community participation followed by an account of a small study exploring the views and practices of two populations. Public health nurses have implemented their 'community as client' role and under favourable conditions would wish to develop further this aspect of their work. Women in the community are aware of the primary healthcare services available to them and as demonstrated by their comments have a holistic understanding of health. The study shows that both public health nurses and women in the community are interested and willing to take part in actions to improve health and welfare. Before genuine community partnership is developed a more defined leadership role which incorporates the skills of both community empowerment and community organization is needed.

Phase I and pharmacokinetic study of tirapazamine (SR 4233) administered every three weeks

Tirapazamine (SR 4233; 3-amino-1,2,4-benzotriazine-1,4-di-N-oxide) is a bioreductive agent exhibiting up to 200 x greater toxicity for hypoxic cells as compared to oxygenated cells. In murine studies, a selective increase in tumor kill was observed when tirapazamine was coadministered with other agents, notably cisplatin. A Phase I study of single-agent tirapazamine administered i.v. every 3 weeks was conducted to determine the toxicity of a schedule for use with systemic chemotherapy. A total of 28 patients were given 50 courses of tirapazamine at doses ranging from 36-450 mg/m2. No tumor responses were observed. Reversible deafness and tinnitus were dose-limiting, with ototoxicity observed in 1 of 6 patients treated at 330 mg/m2, 1 of 4 patients treated at 390 mg/m2, and 3 of 3 patients treated at 450 mg/m2. Muscle cramps, nausea, and vomiting were also observed. Pharmacokinetic studies revealed a greater than dose-proportional increase in the area under the plasma concentration x time curve (AUCs) of the two major metabolites. Patients who developed ototoxicity generally showed higher plasma AUC values for the parent drug and metabolites. The mean plasma tirapazamine AUC at 330 mg/m2 was 1026.5 microgram/ml x min (range 863. 8-1252.3), but no pharmacokinetic data are available for the solitary patient who developed otoxicity at this dose level. These AUC values were in the (estimated) range required for therapeutic effect in murine studies. Ototoxicity was not observed when the AUC of tirapazamine was equal to or less than 1252 microgram/ml x min. The dose of 330 mg/m2 was therefore chosen as an appropriate level for combination chemotherapy studies.

The use of back projection to estimate HIV prevalence among pregnant women in Australia

A statistical method similar to back projection was used to estimate the number of children infected with HIV perinatally from the number of children with AIDS due to perinatal HIV infection. By 31 December 1994 there were 18 children born in Australia and reported to have AIDS due to perinatal HIV infection. Based on these 18 AIDS cases, it was estimated that to the end of 1994 there were between 35 and 57 children born in Australia and infected with HIV perinatally, with a preferred estimate of 43 children. Assuming that the transmission rate of HIV from infected mothers to their babies was in the range 15 to 35%, it was estimated that the prevalence of HIV infection among women giving birth in Australia had increased from 0.03 per 1000 (range 0.02-0.07 per 1000) in 1983-1985 to 0.09 per 1000 (range 0.05-0.20 per 1000) in 1992-1994. This range for the prevalence of HIV infection among pregnant women in 1992-1994 was consistent with estimates of the prevalence from screening studies, and suggests that the prevalence of HIV infection in pregnant women in Australia remains low.

Methanol potentiation of carbon tetrachloride hepatotoxicity: the central role of cytochrome P450

Evidence to explain the enhanced hepatotoxicity of carbon tetrachloride (CCl4) following methanol exposure by inhalation is presented. Hepatic microsomes prepared from male F344 rats exposed to methanol at concentrations up to 10,000 ppm showed increased p-nitrophenol hydroxylase activity but no increase in pentoxyresorufin-O-dealkylase or ethoxyresorufin-O-deethylase activities. Hepatic antioxidant levels, glutathione levels and glutathione-S-transferase activity in methanol-treated animals were not different from controls. In vitro metabolism of CCl4 was also increased in microsomes from methanol-treated animals. Pretreatment with allyl sulfone, a specific chemical inhibitor of cytochrome P450 2E1, abolished the difference in microsomal metabolism between exposed and control animals. This study shows that methanol exposure induces cytochrome P450 2E1, which appears to be the principal toxicokinetic mechanism responsible for the increased metabolism and thus the increased hepatotoxicity of CCl4.

Pulmonary aspiration in a long-term care setting: clinical and laboratory observations and an analysis of risk factors

OBJECTIVE

To determine the incidence and risk factors associated with aspiration in a high risk group in a long-term care setting.

DESIGN

A prospective study of demographic, nutritional, clinical, dental, and survival characteristics in 69 patients who suffered 98 aspirations events from May 1, 1990, to December 31, 1990. Demographic and nutritional data from 192 patients who did not aspirate were collected from September 1991 to December 1991.

SETTING

A long-term care VA facility.

PATIENTS

Long-term care residents, most of whom were neurologically debilitated.

MEASUREMENTS

The incidence of aspiration was measured and the clinical and microbiological characteristics of aspiration-associated nosocomial pneumonia described. Mortality and demographic, clinical, and nutritional characteristics were compared between patients who aspirated and those who did not.

MAIN RESULTS

Twenty-five percent of the study group aspirated during the 8-month observational period, and 56% of the aspiration events progressed to roentgenographically proven cases of nosocomial pneumonia. Six bacteremic episodes were documented, and results of sputum cultures were consistent with mixed Gram-positive and Gram-negative infections. During the study period, patients who aspirated were at three times the risk of dying compared with patients who did not aspirate. Three years later, only 17% of the original group of patients who aspirated were still alive compared with 60% of the patients who had not aspirated. Multivariate analysis identified tube feeding, presence of a hyperextended neck or contractions, malnutrition, and the use of benzodiazepines and anticholinergics as risk factors.

CONCLUSIONS

Pulmonary aspiration is a common and serious event in neurologically impaired long-term care patients. Some risk factors are amenable to change.

Age-specific HIV incidence among homosexually active men in Australia

OBJECTIVE

To estimate age at HIV infection among homosexually active men in Australia.

DESIGN

Age-specific back-projection estimates of HIV incidence.

METHODS

Monthly counts of AIDS among homosexually active men diagnosed by 30 June 1994 and reported by 31 March 1995 were obtained from the National AIDS Registry and were adjusted for reporting delays. The progression rate to AIDS was estimated from a large cohort study of HIV-infected homosexual men, with adjustment for the effect of age at HIV infection and the effect of antiretroviral and prophylactic treatments.

RESULTS

The median age at HIV infection was estimated to have decreased from 31 years of age between 1982 and 1984 to between 23 and 27 years in the periods 1987 to 1989 and 1990 to 1994. Despite the trend to a younger median age at HIV infection during the current epidemic, HIV incidence was estimated to have declined in all age groups from a peak in the mid-1980s. This decline was more pronounced in the older age groups, with more modest reductions in age groups under 30 years.

CONCLUSION

Most HIV infections among homosexually active men since 1987 appear to have occurred in men aged under 30 years. This has implications for education programs aimed at preventing HIV infection among homosexually active men.

Plexiform neurofibroma: a rare cause of obstructive jaundice

A case of obstructive jaundice secondary to a neurofibroma in the common hepatic duct is presented. The histological appearance was that of a plexiform neurofibroma. The clinicopathological features are discussed.

Haemopneumothorax

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Potentiation of carbon tetrachloride hepatotoxicity by inhaled methanol: time course of injury and recovery

Increases in the use of methanol (MeOH) as a transportation fuel would result in greater potential for inhalation exposure. Because oral exposure to MeOH potentiates the hepatotoxicity of carbon tetrachloride (CCl4), we examined the ability of inhaled MeOH to potentiate CCl4 hepatotoxicity and the time course of injury and recovery. Adult male F-344 rats were exposed to 0 or to 10,000 ppm MeOH by inhalation for 6 h and gavaged with 0.075 ml CCl4/kg 24 h later. Hepatotoxicity was assessed 0.5, 1, 1.5, 2, 3, 7, 15, 30, and 61 d after CCl4 exposure. For CCl4 alone, hepatotoxicity was most severe at 0.5 and 1 d, when minimal centrilobular hepatocellular necrosis and predominately mild centrilobular hepatocellular vacuolar degeneration occurred. By d 3, the livers from the CCl4 rats were histologically normal. For MeOH+CCl4, peak severity of hepatic injury was at 1 and 1.5 d, when moderate centrilobular necrosis and moderate/marked centrilobular degeneration occurred. MeOH+CCl4 resulted in serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) that were increased, relative to CCl4 alone, 171- and 113-fold, respectively, on d 1, and 166- and 140-fold, respectively, on d 1.5. Significant serum elevations in MeOH+CCl4 rats, relative to CCl4 alone rats, were present until d 7 and d 15 for AST and ALT, respectively. By d 3 and d 7, degeneration and necrosis, respectively, due to MeOH+CCl4 were essentially resolved. On d 7, the MeOH+CCl4 hepatic injury consisted mainly of chronic inflammation and centrilobular fibrosis. By d 30, the livers of MeOH+CCl4 rats were histologically normal. These data demonstrate that inhaled MeOH potentiates the hepatotoxicity of orally ingested CCl4, increasing the severity of CCl4 hepatotoxicity as well as the time required for recovery.

Sperm motility in the presence of boundaries

The fluid dynamics of sperm motility near both rigid and elastic walls is studied using the immersed boundary method. Simulations of both single and interacting organisms are presented. In particular, we find that nearby organisms originally undulating with a 90 degree phase shift may adjust their relative swimming velocities and phase-lock. Comparisons with previous analytical results are also discussed. The tendency of a near-wall to attract organisms is demonstrated.