Randomized phase III study of temozolomide versus dacarbazine in the treatment of patients with advanced metastatic malignant melanoma

PURPOSE

To compare, in 305 patients with advanced metastatic melanoma, temozolomide and dacarbazine (DTIC) in terms of overall survival, progression-free survival (PFS), objective response, and safety, and to assess health-related quality of life (QOL) and pharmacokinetics of both drugs and their metabolite, 5-(3-methyltriazen-1-yl)imidazole-4-carboximide (MTIC).

PATIENTS AND METHODS

Patients were randomized to receive either oral temozolomide at a starting dosage of 200 mg/m(2)/d for 5 days every 28 days or intravenous (IV) DTIC at a starting dosage of 250 mg/m(2)/d for 5 days every 21 days.

RESULTS

In the intent-to-treat population, median survival time was 7.7 months for patients treated with temozolomide and 6.4 months for those treated with DTIC (hazards ratio, 1.18; 95% confidence interval [CI], 0.92 to 1.52). Median PFS time was significantly longer in the temozolomide-treated group (1.9 months) than in the DTIC-treated group (1.5 months) (P =.012; hazards ratio, 1.37; 95% CI, 1.07 to 1.75). No major difference in drug safety was observed. Temozolomide was well tolerated and produced a noncumulative, transient myelosuppression late in the 28-day cycle. The most common nonhematologic toxicities were mild to moderate nausea and vomiting, which were easily managed. Temozolomide therapy improved health-related QOL; more patients showed improvement or maintenance of physical functioning at week 12. Systemic exposure (area under the curve) to the parent drug and the active metabolite, MTIC, was higher after treatment with oral temozolomide than after IV administration of DTIC.

CONCLUSION

Temozolomide demonstrates efficacy equal to that of DTIC and is an oral alternative for patients with advanced metastatic melanoma.

Emulsion-based delivery systems for lipophilic bioactive components

There is a pressing need for edible delivery systems to encapsulate, protect, and release bioactive lipids within the food, medical, and pharmaceutical industries. The fact that these delivery systems must be edible puts constraints on the type of ingredients and processing operations that can be used to create them. Emulsion technology is particularly suited for the design and fabrication of delivery systems for encapsulating bioactive lipids. This review provides a brief overview of the major bioactive lipids that need to be delivered within the food industry (for example, omega-3 fatty acids, carotenoids, and phytosterols), highlighting the main challenges to their current incorporation into foods. We then provide an overview of a number of emulsion-based technologies that could be used as edible delivery systems by the food and other industries, including conventional emulsions, multiple emulsions, multilayer emulsions, solid lipid particles, and filled hydrogel particles. Each of these delivery systems could be produced from food-grade (GRAS) ingredients (for example, lipids, proteins, polysaccharides, surfactants, and minerals) using simple processing operations (for example, mixing, homogenizing, and thermal processing). For each type of delivery system, we describe its structure, preparation, advantages, limitations, and potential applications. This knowledge can be used to facilitate the selection of the most appropriate emulsion-based delivery system for specific applications.

Intermittent dislocation flow in viscoplastic deformation

The viscoplastic deformation (creep) of crystalline materials under constant stress involves the motion of a large number of interacting dislocations. Analytical methods and sophisticated 'dislocation dynamics' simulations have proved very effective in the study of dislocation patterning, and have led to macroscopic constitutive laws of plastic deformation. Yet, a statistical analysis of the dynamics of an assembly of interacting dislocations has not hitherto been performed. Here we report acoustic emission measurements on stressed ice single crystals, the results of which indicate that dislocations move in a scale-free intermittent fashion. This result is confirmed by numerical simulations of a model of interacting dislocations that successfully reproduces the main features of the experiment. We find that dislocations generate a slowly evolving configuration landscape which coexists with rapid collective rearrangements. These rearrangements involve a comparatively small fraction of the dislocations and lead to an intermittent behaviour of the net plastic response. This basic dynamical picture appears to be a generic feature in the deformation of many other materials. Moreover, it should provide a framework for discussing fundamental aspects of plasticity that goes beyond standard mean-field approaches that see plastic deformation as a smooth laminar flow.

Skin cancer risk in relation to toenail arsenic concentrations in a US population-based case-control study

Arsenic is a known carcinogen specifically linked to skin cancer occurrence in regions with highly contaminated drinking water or in individuals who took arsenic-containing medicines. Presently, it is unknown whether such effects occur at environmental levels found in the United States. To address this question, the authors used data collected on 587 basal cell and 284 squamous cell skin cancer cases and 524 controls interviewed as part of a case-control study conducted in New Hampshire between 1993 and 1996. Arsenic was determined in toenail clippings using instrumental neutron activation analysis. The odds ratios for squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) were close to unity in all but the highest category. Among individuals with toenail arsenic concentrations above the 97th percentile, the adjusted odds ratios were 2.07 (95% confidence interval (CI): 0.92, 4.66) for SCC and 1.44 (95% CI: 0.74, 2.81) for BCC, compared with those with concentrations at or below the median. While the risks of SCC and BCC did not appear elevated at the toenail arsenic concentrations detected in most study subjects, the authors cannot exclude the possibility of a dose-related increase at the highest levels of exposure experienced in the New Hampshire population.

The oligodendroglial lineage marker OLIG2 is universally expressed in diffuse gliomas

Astrocytomas, oligodendrogliomas, and oligoastrocytomas, collectively referred to as diffuse gliomas, are the most common primary brain tumors. These tumors are classified by histologic similarity to differentiated astrocytes and oligodendrocytes, but this approach has major limitations in guiding modern treatment and research. Lineage markers represent a potentially useful adjunct to morphologic classification. The murine bHLH transcription factors Olig1 and Olig2 are expressed in neural progenitors and oligodendroglia and are essential for oligodendrocyte development. High OLIG expression alone has been proposed to distinguish oligodendrogliomas from astrocytomas, so we critically evaluated OLIG2 as a marker by immunohistochemical and oligonucleotide microarray analysis. OLIG2 protein is faithfully restricted to normal oligodendroglia and their progenitors in human brain. Immunohistochemical analysis of 180 primary, metastatic, and non-neural human tumors shows OLIG2 is highly expressed in all diffuse gliomas. Immunohistochemistry and microarray analyses demonstrate higher OLIG2 in anaplastic oligodendrogliomas versus glioblastomas, which are heterogeneous with respect to OLIG2 levels. OLIG2 protein expression is present but inconsistent and generally lower in most other brain tumors and is absent in non-neuroectodermal tumors. Overall, OLIG2 is a useful marker of diffuse gliomas as a class. However, expression heterogeneity of OLIG2 in astrocytomas precludes immunohistochemical classification of individual gliomas by OLIG2 alone.

Carcinoma of the prostate gland: MR imaging with pelvic phased-array coils versus integrated endorectal--pelvic phased-array coils

PURPOSE

To compare the performance of pelvic phased-array (PPA) coils and integrated endorectal PPA coils in evaluation of local extent of prostate cancer.

MATERIALS AND METHODS

Seventy-one men underwent magnetic resonance (MR) imaging within 3 weeks of radical prostatectomy. MR findings of tumor, extracapsular extension, seminal vesicle invasion, nodal involvement, and stage were compared with step-sectioned (3-4-mm intervals) whole-mounted pathologic specimens. Prospective consensus versus single-reader interpretation (kappa statistics) and PPA versus integrated endorectal PPA coils (McNemar test) were compared, and a rating scale of 1-6 was developed for analysis of receiver operating characteristics. Statistical significance was calculated at delta = .05.

RESULTS

Comparison between consensus and single-reader image interpretation showed positive but poor agreement (kappa = .38) and no statistical significance. Staging accuracy was better (difference approached significance) for integrated endorectal PPA coils (77%) than for PPA coils (68%).

CONCLUSION

The integrated endorectal PPA coil is better for evaluation of local prostatic cancer than is the PPA coil.

Transmyocardial laser revascularisation compared with continued medical therapy for treatment of refractory angina pectoris: a prospective randomised trial. ATLANTIC Investigators. Angina Treatments-Lasers and Normal Therapies in Comparison

BACKGROUND

Transmyocardial revascularisation (TMR) is an operative treatment for refractory angina pectoris when bypass surgery or percutaneous transluminal angioplasty is not indicated. We did a prospective randomised trial to compare TMR with continued medication.

METHODS

We recruited 182 patients from 16 US centres with Canadian Cardiovascular Society Angina (CCSA) score III (38%) or IV (62%), reversible ischaemia, and incomplete response to other therapies. Patients were randomly assigned TMR and continued medication (n=92) or continued medication alone (n=90). Baseline assessments were angina class, exercise tolerance, Seattle angina questionnaire for quality of life, and dipyridamole thallium stress test. We reassessed patients at 3 months, 6 months, and 12 months, with independent masked angina assessment at 12 months.

FINDINGS

At 12 months, total exercise tolerance increased by a median of 65 s in the TMR group compared with a 46 s decrease in the medication-only group (p<0.0001, median difference 111 s). Independent CCSA score was II or lower in 47.8% in the TMR group compared with 14.3% in the medication-only group (p<0.001). Each Seattle angina questionnaire index increased in the TMR group significantly more than in the medication-only group (p<0.001).

INTERPRETATION

TMR lowered angina scores, increased exercise tolerance time, and improved patients' perceptions of quality of life. This operative treatment provided clinical benefits in patients with no other therapeutic options.

Seizure-associated brain injury in term newborns with perinatal asphyxia

BACKGROUND

There is controversy over whether seizures, the most common manifestation of neonatal brain injury, may themselves damage the developing brain.

OBJECTIVE

To determine if neonatal seizures are independently associated with brain injury in newborns with perinatal asphyxia.

METHODS

Ninety term neonates were studied with MRI and single-voxel (1)H-MRS on median day of life 6 (range 1 to 13 days). The severity of MR abnormality in the (1)H-MRS regions of interest was scored using a validated scale. Seizure severity was scored based on seizure frequency and duration, EEG findings, and anticonvulsant administration. Multivariable linear regression tested the independent association of seizure severity with impaired cerebral metabolism measured by lactate/choline and compromised neuronal integrity measured by N-acetylaspartate/choline in both regions.

RESULTS

Clinical seizures occurred in 33 of 90 infants (37%). Seizure severity was associated with increased lactate/choline in both the intervascular boundary zone (p < 0.001) and the basal nuclei (p = 0.011) when controlling for potential confounders of MRI abnormalities and amount of resuscitation at birth. Each increase in seizure score was independently associated with a 21% increase in lactate/choline in the intervascular boundary zone (95% CI, 5.1-38.2%) and a 15% increase in the basal nuclei (95% CI, 0.1-31.7%). Seizure severity was independently associated with diminished N-acetylaspartate/choline in the intervascular boundary zone (p = 0.034).

CONCLUSION

The severity of seizures in human newborns with perinatal asphyxia is independently associated with brain injury and is not limited to structural damage detectable by MRI.

Intracellular Ca(2+) dynamics and the stability of ventricular tachycardia

Ventricular fibrillation (VF), the major cause of sudden cardiac death, is typically preceded by ventricular tachycardia (VT), but the mechanisms underlying the transition from VT to VF are poorly understood. Intracellular Ca(2+) overload occurs during rapid heart rates typical of VT and is also known to promote arrhythmias. We therefore studied the role of intracellular Ca(2+) dynamics in the transition from VT to VF, using a combined experimental and mathematical modeling approach. Our results show that 1) rapid pacing of rabbit ventricular myocytes at 35 degrees C led to increased intracellular Ca(2+) levels and complex patterns of action potential (AP) configuration and the intracellular Ca(2+) transients; 2) the complex patterns of the Ca(2+) transient arose directly from the dynamics of intracellular Ca(2+) cycling, and were not merely passive responses to beat-to-beat alterations in AP; 3) the complex Ca(2+) dynamics were simulated in a modified version of the Luo-Rudy (LR) ventricular action potential with improved intracellular Ca(2+) dynamics, and showed good agreement with the experimental findings in isolated myocytes; and 4) when incorporated into simulated two-dimensional cardiac tissue, this action potential model produced a form of spiral wave breakup from VT to a VF-like state in which intracellular Ca(2+) dynamics played a key role through its influence on Ca(2+)-sensitive membrane currents such as I(Ca), I(NaCa), and I(ns(Ca)). To the extent that spiral wave breakup is useful as a model for the transition from VT to VF, these findings suggest that intracellular Ca(2+) dynamics may play an important role in the destabilization of VT and its degeneration into VF.

Estrogen receptor binding to DNA is not required for its activity through the nonclassical AP1 pathway

In the classical signaling pathway, the estrogen receptor (ER) binds directly to estrogen response elements (EREs) to regulate gene transcription. To test the hypothesis that the nonclassical pathway involves ER interactions with other proteins rather than direct binding to DNA, mutations were introduced into the DNA binding domain (DBD) of the mouse ERalpha. The effects of these DBD mutations were examined in DNA binding assays using reporter constructs containing either EREs (classical) or AP1 (nonclassical) response elements. Using the AP1 reporter, there was a reversal of ER action relative to that seen with the ERE reporter. Estradiol induced suppression, and the antiestrogen ICI 182,780 stimulated transcription of the AP1 reporter. DBD mutations in the proximal (P-box) of the first zinc finger of the ER (E207A/G208A and E207G/G208S) eliminated ERE binding. These mutants were inactive using the ERE reporter but retained partial or full activity with the AP1 reporter. The DBD mutant ERs interacted with Jun when tested in mammalian cell two-hybrid assays. Two mutations (K366D and I362R) in the ER ligand binding domain known to alter coactivator interactions impaired transcriptional responses using either the ERE or AP1 reporters. We concluded that ER action through the AP1 response element involves interactions with other promoter-bound proteins instead of, or in addition to, direct binding to DNA. Interactions with coactivators were required for both pathways. These data supported a model in which ER-mediated transcriptional activation or repression is dependent on the ligand and the nature of the response element in the target gene.

Diurnal pattern of QTc interval: how long is prolonged? Possible relation to circadian triggers of cardiovascular events

OBJECTIVES

This study sought to evaluate the range and variability of the QT and corrected QT (QTc) intervals over 24 h and to assess their pattern and relation to heart rate variability.

BACKGROUND

Recent Holter monitoring data have revealed a high degree of daily variability in the QTc interval. The pattern of this variability and its relation to heart rate variability remain poorly characterized.

METHODS

We developed and validated a new method for continuous measurement of QT intervals from three-channel, 24-h Holter recordings. Average RR, QT, QTc and heart rate variability were measured from 5-min segments of data from 21 healthy subjects.

RESULTS

Measurement of 6,048 segments showed mean (+/- SD) RR, QT and QTc intervals of 830 +/- 100, 407 +/- 23 and 445 +/- 16 ms, respectively (mean QTc interval for men 434 +/- 12 ms, 457 +/- 10 ms for women, p < 0.0001). The average maximal QTc interval was 495 +/- 21 ms and the average QTc range 95 +/- 20 ms. The maximal QTc interval was > or = 500 ms in 6 subjects and > or = 490 ms in 13. The 95% upper confidence limit for the mean 24-h QTc interval was 452 ms (men 439 ms, women 461 ms). The RR, QT and QTc intervals and the high frequency component of heart rate variability were greater during sleep. Both the QTc interval and the variability between hourly minimal and maximal QTc intervals reached their circadian peak shortly after awakening, before declining to daytime levels.

CONCLUSIONS

The maximal QTc interval over 24 h in normal subjects is longer than heretofore thought. Both QT and QTc intervals are longer during sleep. The QTc interval and QTc variability reach a peak shortly after awakening, which may reflect increased autonomic instability during early waking hours, and the time of the peak value corresponds in time to the period of reported increased vulnerability to ventricular tachycardia and sudden cardiac death. These findings have implications regarding the definition of QT prolongation and its use in predicting arrhythmias and sudden death.

Effect of surfactant surface coverage on formation of solid lipid nanoparticles (SLN)

The effect of surfactant surface coverage on formation and stability of Tween 20 stabilized tripalmitin solid lipid nanoparticles (SLN) was investigated. A lipid phase (10% w/w tripalmitin) and an aqueous phase (2% w/w Tween 20, 10 mM phosphate buffer, pH 7) were heated to 75 degrees C and then homogenized using a microfluidizer. The resulting oil-in-water emulsion was kept at a temperature (37 degrees C) above the crystallization temperature of the tripalmitin to prevent solidification of emulsion droplets, and additional surfactant at various concentrations (0-5% w/w Tween 20) was added. Droplets were then cooled to 5 degrees C to initiate crystallization and stored at 20 degrees C for 24 h. Particle size and/or aggregation were examined visually and by light scattering, and crystallization behavior was examined by differential scanning calorimetry (DSC). Excess Tween 20 concentration remaining in the aqueous phase was measured by surface tensiometry. Emulsion droplets after homogenization had a mean particle diameter of 134.1+/-2.0 nm and a polydispersity index of 0.08+/-0.01. After cooling to 5 degrees C at low Tween 20 concentrations, SLN dispersions rapidly gelled due to aggregation of particles driven by hydrophobic attraction between insufficiently covered lipid crystal surfaces. Upon addition of 1-5% w/w Tween 20, SLN dispersions became increasingly stable. At low added Tween 20 concentration (<1% w/w) the SLN formed gels but only increased slightly at higher surfactant concentrations (>1% w/w). The Tween 20 concentration in the aqueous phase decreased after tripalmitin crystallization suggesting additional surfactant adsorption onto solid surfaces. At higher Tween 20 concentrations, SLN had increasingly complex crystal structures as evidenced by the appearance of additional thermal transition peaks in the DSC. The results suggest that surfactant coverage at the interface may influence crystal structure and stability of solid lipid nanoparticles via surface-mediated crystal growth.

Morphine inhibits spontaneous and cytokine-enhanced natural killer cell cytotoxicity in volunteers

BACKGROUND

Opioids are used by patients who have conditions ranging from the acute pain of surgery and chronic cancer pain to substance abuse. Despite their widespread use and considerable experimental data about them, little is known about how opioids may alter in vivo immunity in humans. This study was designed to evaluate the in vivo effect of morphine on human peripheral blood immune functions.

METHODS

Healthy volunteers underwent continuous exposure to morphine for 36 h including a 24-h intravenous infusion in the hospital. Peripheral blood was drawn for immune function studies at five measurement times before, during, and after morphine exposure. Peripheral blood mononuclear cells were tested for acute and gamma-interferon-stimulated natural killer cell cytotoxicity (NKCC), antibody-dependent cell cytotoxicity, antibody Fc receptor expression, and human immunodeficiency virus infectivity.

RESULTS

Significant suppression of NKCC was observed at 2 and 24 h after the onset of intravenous morphine exposure. Suppression of NKCC persisted for 24 h after termination of morphine infusion in a "high"-dose study group. gamma-Interferon-stimulated NKCC and antibody-dependent cell cytotoxicity were also decreased after 24 h of intravenous morphine exposure. No effect on Fc receptor expression was observed. Mean virus antigen production after lymphocyte infection with human immunodeficiency virus was not increased (p24 100 ng/ml after morphine vs. 43 ng/ml before morphine; P = 0.17).

CONCLUSIONS

These results suggest that morphine administration, at doses within the range of analgesic use, can cause measurable suppression of some components of the human cellular immune system.

Functional compartmentation of glycolytic versus oxidative metabolism in isolated rabbit heart

To investigate whether energy derived from glycolytic and oxidative metabolism are preferentially used for different functions in heart, tension, intracellular potential, and extracellular [K+] and pH (using triple barrel K/pH electrodes, tip diameter 0.5 mm) were monitored in isolated arterially perfused rabbit interventricular septa during exposure to hypoxia and metabolic inhibitors. Myocardial content of high energy phosphates, lactate, and glycogen were determined under the same conditions. Inhibiting oxidative metabolism with hypoxia, dinitrophenol (10(-5)M), or Na-azide (10(-3)M) caused marked suppression of tension (by 73 +/- 5, 65 +/- 8, and 50 +/- 14%, respectively) and a small increase in [K+]0 (0.8 +/- 0.4, 0.5 +/- 0.25, and 0.4 +/- 0.2 mM, respectively) after 10 min. Inhibiting glycolysis with iodoacetate (IAA) (10(-3)M) had a much smaller suppressant effect on tension (28 +/- 24%) but markedly increased [K+]0 accumulation (by 1.8 +/- 1.1 mM) at 10 min. These differences, when IAA was compared individually to the other interventions, were highly significant. The shortening of action potential duration was not significantly different for the four interventions. pH0 increased slightly during IAA (+0.04-+0.06 U) and fell during the other interventions (-0.10--0.16 U), but this did not account for the differences in [K+]0 accumulation and tension between inhibition of glycolytic vs. oxidative metabolism. Except for hypoxia, total cellular content of high energy phosphates was not significantly depressed under the various conditions. This data suggests that energy from glycolysis is preferentially used to support sarcolemmal function (as manifested by K+ loss), whereas oxidatively derived energy preferentially supports contractile function. Indexing terms: cardiac metabolism, extracellular pH, metabolic inhibitors, hypoxia, extracellular K+ accumulation, and glycolysis.

High-affinity binding of the bactericidal/permeability-increasing protein and a recombinant amino-terminal fragment to the lipid A region of lipopolysaccharide

Bactericidal/permeability-increasing protein (BPI) is a 55-kDa cationic protein (nBPI55) elaborated by polymorphonuclear neutrophils (PMN). BPI has potent bactericidal activity against a wide variety of gram-negative organisms and neutralizes endotoxin activities. An N-terminal fragment of nBPI55 exhibits the bactericidal and antiendotoxin properties of the holoprotein. To further characterize the biological activities of the N-terminal fragment, a recombinant protein (rBPI23) corresponding to the first 199 amino acids of human BPI was produced and purified. rBPI23 had antibacterial activity equivalent to that of nBPI55 against Escherichia coli J5. Furthermore, both rBPI23 and nBPI55 bound identically to a broad range of R- and S-form lipopolysaccharides (LPS) and to natural and synthetic lipid A. Binding of radiolabeled nBPI55 to LPS was inhibited in an identical fashion by either nBPI55 or rBPI23. The binding of both proteins to immobilized E. coli J5 lipid A was inhibited in a comparable fashion by long- or short-chain LPS or lipid A. The binding of both rBPI23 and nBPI55 was specific, saturable, and of high affinity, with an apparent Kd of approximately 2 to 5 nM for all ligands tested. These results demonstrate that BPI recognizes the highly conserved lipid A region of bacterial LPS via residues contained within the amino-terminal portion of the BPI molecule.

Efficacy of desmopressin in the treatment of nocturia: a double-blind placebo-controlled study in men

OBJECTIVE

To investigate the efficacy and safety of oral desmopressin in the treatment of nocturia in men.

PATIENTS AND METHODS

Men aged >/=18 years with verified nocturia (>or=two voids/night) and nocturnal urine production greater than their maximum functional bladder capacity were recruited. A 3-week dose-titration phase established the optimum desmopressin dose (0.1, 0.2 or 0.4 mg). After a 1-week 'washout' period, patients who responded in the dose-titration period were randomized to receive the optimal dose of desmopressin or placebo in a double-blind design for 3 weeks.

RESULTS

In all, 151 patients entered the double-blind period (86 treated with desmopressin, 65 with placebo). In the desmopressin group 28 (34%) patients and in the placebo group two (3%) patients (P<0.001) had fewer than half the number of nocturnal voids relative to baseline; the mean number of nocturnal voids decreased from 3.0 to 1.7 and from 3.2 to 2.7, respectively, reflecting a mean decrease of 43% and 12% (P<0.001). The mean duration of the first sleep period increased by 59% (from 2.7 to 4.5 h) in the desmopressin group, compared with an increase of 21% (from 2.5 to 2.9 h) in the placebo group (P<0.001). The mean nocturnal diuresis decreased by 36% (from 1.5 to 0.9 mL/min) in the desmopressin group and by 6% (from 1.7 to 1.5 mL/min) in the placebo group (P<0.001). The mean ratio of night/24-h urine volume decreased by 23% and 1% (P<0.001), and the mean ratio of night/day urine volume decreased by 27% and increased by 3% (P<0.001) for the desmopressin and placebo groups, respectively. In the double-blind treatment period, similar numbers of patients had adverse events; 15 (17%) patients in the desmopressin and 16 (25%) patients in the placebo group. Most adverse events were mild. Serum sodium levels were <130 mmol/L in 10 (4%) patients and this occurred during dose-titration.

CONCLUSIONS

Orally administered desmopressin is an effective and well-tolerated treatment for nocturia in men.

Risk factors for developing cutaneous melanoma and criteria for identifying persons at risk: multicenter case-control study of the Central Malignant Melanoma Registry of the German Dermatological Society

Different pigmentary characteristics as well as different parameters of sun exposure have previously been identified as risk factors for developing cutaneous melanoma. The aim of the present study was to identify significant risk factors, determine the related magnitude of their estimated relative risks, and define criteria for the detection of persons at risk. Five hundred thirteen melanoma patients and 498 controls matched for age and sex underwent a whole-body examination for the number and type of melanocytic lesions and were interviewed on ultraviolet exposure and other potential risk factors. The total number of common melanocytic nevi on all body sites represented the most important risk factor in multiple logistic regression analysis with a relative risk of 7.6 for subjects with more than 100 versus no more than 10 melanocytic nevi. Other significant independent risk factors were the number of atypical melanocytic nevi (relative risk, 6.1 for at least 5 melanocytic nevi versus none), the number of actinic lentigines (relative risk, 3.5 for many versus none), hair color, skin type, and reported melanocytic nevus growth. No single parameter of sun exposure was significantly related to melanoma risk in the multivariate analysis. Groups with an estimated relative risk between 1 and 121.0 were distinguished by considering common and atypical melanocytic nevi as well as actinic lentigines as the decisive criteria. In conclusion, even without any information on the case history, whole-body examination and diagnosis of pigmented lesions was found to be an effective strategy for identifying persons at risk of developing melanoma. Furthermore, clinical recognition of at least 5 atypical melanocytic nevi without histologic examination is a key for identifying subjects at high risk.

Cimetidine, cigarette smoking, and recurrence of duodenal ulcer

Three hundred seventy patients with recently healed duodenal ulcer entered into a one-year, double-blind, randomized multicenter trial comparing placebo with three different dose schedules of cimetidine (200 mg twice a day, 300 mg twice a day, and 400 mg at bedtime) for the prevention of recurrent duodenal ulcer. By the end of one year, the cumulative symptomatic recurrence rate as demonstrated by endoscopy was similar for the patients receiving the three dosages of cimetidine (19 per cent, 15 per cent, and 13 per cent, respectively; not significant), whereas the placebo-treated group had a 34.7 per cent symptomatic recurrence rate (P less than 0.01 as compared with each cimetidine group). Cigarette smoking was found to be an important variable; among the placebo recipients ulcer recurrence was significantly more likely in smokers (72 per cent) than in nonsmokers (21 per cent, P less than 0.001). The frequency of ulcer recurrence in smokers was significantly reduced by treatment with cimetidine (from 72 per cent to 34 per cent, P less than 0.). Smokers who received cimetidine were at least as likely to have a recurrence as were nonsmokers who received placebo (34 per cent vs. 21 per cent, not significant). Thus, smoking appears to be a major factor in recurrence of duodenal ulcer, and in smokers, giving up smoking may be more important in the prevention of ulcer recurrences than administration of cimetidine.

The potent anti-Staphylococcus aureus activity of a sterile rabbit inflammatory fluid is due to a 14-kD phospholipase A2

The cell-free fluid (ascitic fluid, AF) of a sterile inflammatory peritoneal exudate elicited in rabbits is potently bactericidal for complement-resistant gram-negative as well as gram-positive bacterial species. This activity is absent in plasma. We now show that essentially all activity in AF against Staphylococcus aureus is attributable to a group II 14-kD phospholipase A2 (PLA2), previously purified from AF in this laboratory. Antistaphylococcal activity of purified PLA2 and of whole AF containing a corresponding amount of PLA2 was comparable and blocked by anti-AF-PLA2 serum. At concentrations present in AF (approximately 10 nM), AF PLA2 kills > 2 logs of 10(6) S. aureus/ml, including methicillin-resistant clinical isolates, and other species of gram-positive bacteria. Human group II PLA2 displays similar bactericidal activity toward S. aureus (LD90 approximately 1-5 nM), whereas 14-kD PLA2 from pig pancreas and snake venom are inactive even at micromolar doses. Bacterial killing by PLA2 requires Ca2+ and catalytic activity and is accompanied by bacterial phospholipolysis and disruption of the bacterial cell membrane and cell wall. These findings reveal that group II extracellular PLA2, the function of which at inflammatory sites has been unclear, is an extraordinarily potent endogenous antibiotic against S. aureus and other gram-positive bacteria.

Risk of basal cell and squamous cell skin cancers after ionizing radiation therapy. For The Skin Cancer Prevention Study Group

BACKGROUND

Human evidence that ionizing radiation is carcinogenic first came from reports of nonmelanoma skin cancers (NMSCs) on the hands of workers using early radiation devices. An increased risk of NMSC has been observed among uranium miners, radiologists, and individuals treated with x rays in childhood for tinea capitis (ringworm of the scalp) or for thymic enlargement; NMSC is one of the cancers most strongly associated with the atomic bombing of Hiroshima and Nagasaki. Although exposure to ionizing radiation is a known cause of NMSC, it is not yet clear whether therapeutic radiation causes both major histologic types of NMSC, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Additionally, the potentially modifying effects, such as latency, age when treated, and type of treatment, are not well understood.

PURPOSE

We investigated the relative risks of BCC and SCC associated with previous radiation therapy and evaluated these risks in relation to age and time since initial treatment and the medical condition for which radiation therapy was given.

METHODS

The study group comprised individual diagnosed with at least one BCC or SCC from January 1980 through February 1986, who were recruited to participate in a skin cancer prevention trial designed to test whether oral beta-carotene supplementation would reduce the risk of new NMSCs. Patients were identified through the dermatology and pathology records of academic medical centers in Hanover, NH; Los Angeles, CA; San Francisco, CA; and Minneapolis, MN. Each participant completed a questionnaire detailing lifetime residence, pigmentary characteristics, occupational and recreational sun exposure, and history of radiation therapy. At enrollment, a study dermatologist assessed skin type (tendency to burn or tan) and extent of actinic skin damage. Participants were followed with an annual dermatologic examination for an average of 4 years. Of the 5232 potentially eligible individuals, 1805 were enrolled in the trial. We excluded 112 patients who reported previous radiation therapy for skin cancer only and three with missing information on whether they were ever treated with radiation therapy, leaving 1690 patients for the analysis. Approximately 4% of the patients died or discontinued participation for other reasons during each study year. We examined time to occurrence of first new histopathologically confirmed BCC and SCC during the follow-up period in relation to history of radiation therapy (for reasons other than NMSC) using a proportional hazards model. A multiple end points survival model was used to compare the rate ratios (RRs) for BCC and SCC. We also used a longitudinal method of analysis to compute the RR of total new BCC and SCC tumors per person per study year associated with radiation therapy. Using this method, we additionally assessed the potential modifying effects of age at treatment, latency, and type of therapy. All P values were derived from two-sided statistical tests of significance.

RESULTS

Among the participants we studied, 597 developed a new BCC (n = 1553 tumors) and 118 developed a new SCC (n = 179 tumors). The time to first new BCC, but not SCC, was associated with prior radiation therapy (RR = 1.7; 95% confidence interval [CI] = 1.4-2.0 and RR = 1.0; 95% CI = 0.6-1.7, respectively; P = .03 for the difference between the RRs). The RR of total BCC tumors was slightly higher (RR = 2.3; 95% CI = 1.7-3.1), but it was still unity for SCC (RR = 1.0; 95% CI = 0.5-1.9). BCC risk appeared to increase with younger age at exposure and time since initially treated, although these effects were only marginally statistically significant (P for trend = .06 and .07, respectively). Also, risk of BCC was more strongly related to treatment for acne (RR = 3.3; 95% CI = 2.1-5.2) than other conditions.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that exposure to therapeutic radiation is associated with BCC but not with SCC.

Human bactericidal/permeability-increasing protein and a recombinant NH2-terminal fragment cause killing of serum-resistant gram-negative bacteria in whole blood and inhibit tumor necrosis factor release induced by the bacteria

The bactericidal/permeability-increasing protein (BPI) of neutrophils and BPI fragments neutralize the effects of isolated Gram-negative bacterial lipopolysaccharides both in vitro and in vivo. Since endotoxin most commonly enters the host as constituents of invading Gram-negative bacteria, we raised the question: Can BPI and its bioactive fragments also protect against whole bacteria? To determine whether the bactericidal and endotoxin-neutralizing activities of BPI/fragments are expressed when Gram-negative bacteria are introduced to the complex environment of whole blood we examined the effects of added BPI and proteolytically prepared and recombinant NH2-terminal fragments on: (a) the fate of serum-resistant encapsulated Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa that survive the antibacterial actions of whole blood and (b) the ability of these bacteria to trigger cytokine release. Added BPI in nanomolar concentrations killed each of three encapsulated strains of E. coli and in closely parallel fashion inhibited tumor necrosis factor (TNF) release. Holo-BPI and its NH2-terminal fragment were equipotent toward a rough LPS chemotype K1-encapsulated strain, but the fragment was substantially more potent than holo-BPI toward two encapsulated smooth LPS chemotype strains. TNF release induced by K. pneumoniae and P. aeruginosa was also inhibited by both holo-BPI and fragment but, at the protein concentrations tested, P. aeruginosa was killed only by the fragment and K. pneumoniae was not killed by either protein. The bactericidal action of BPI/fragment toward E. coli is inhibited by C7-depleted serum, but accelerated by normal serum, indicating that BPI, acting in synergy with late complement components, enhances extracellular killing of serum-resistant bacteria. Thus, BPI and an even more potent NH2-terminal fragment may protect against Gram-negative bacteria in the host by blocking bacterial proliferation as well as endotoxin-mediated effects, not only as components of the intracellular antibacterial arsenal of the neutrophil, but also as potentially therapeutic extracellular agents.

Bactericidal/permeability-increasing protein (BPI) and lipopolysaccharide-binding protein (LBP): structure, function and regulation in host defence against Gram-negative bacteria

Lipopolysaccharide-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI) are closely related endotoxin-binding proteins that function in a co-ordinated manner to facilitate an integrated host response to invading Gram-negative bacteria. Differences in the structure and function of BPI and LBP, as well as differences in their mobilization, permit highly sensitive pro-inflammatory responses to small numbers of bacteria at the onset of bacterial invasion and, later, efficient elimination of viable bacteria and their remnants and of endotoxin-driven inflammation.

Role of the bactericidal/permeability-increasing protein in host defence

Much has been learned recently about the structure and function of 55 kDa bactericidal/permeability-increasing protein (BPI), a member of a genomically conserved lipid-interactive protein family. Analysis of BPI fragments and the crystal structure of human BPI have established that BPI consists of two functionally distinct domains: a potently antibacterial and anti-endotoxin amino-terminal domain (approximately 20 kDa) and a carboxy-terminal portion that imparts opsonic activity to BPI. A recombinant amino-terminal fragment (rBPI21) protects animals against the effects of Gram-negative bacteria and endotoxin. In man, rBPI21 is nontoxic and non-immunogenic and is in Phase II/III clinical trials with apparent therapeutic benefit.