Pyrazole Ureas as Low Dose, CNS Penetrant Glucosylceramide Synthase Inhibitors for the Treatment of Parkinson's Disease

Parkinson's disease is the second most prevalent progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. Loss-of-function mutations in GBA, the gene that encodes for the lysosomal enzyme glucosylcerebrosidase, are a major genetic risk factor for the development of Parkinson's disease potentially through the accumulation of glucosylceramide and glucosylsphingosine in the CNS. A therapeutic strategy to reduce glycosphingolipid accumulation in the CNS would entail inhibition of the enzyme responsible for their synthesis, glucosylceramide synthase (GCS). Herein, we report the optimization of a bicyclic pyrazole amide GCS inhibitor discovered through HTS to low dose, oral, CNS penetrant, bicyclic pyrazole urea GCSi's with in vivo activity in mouse models and ex vivo activity in iPSC neuronal models of synucleinopathy and lysosomal dysfunction. This was accomplished through the judicious use of parallel medicinal chemistry, direct-to-biology screening, physics-based rationalization of transporter profiles, pharmacophore modeling, and use a novel metric: volume ligand efficiency.

Discovery of 4-aryl-7-hydroxyindoline-based P2Y1 antagonists as novel antiplatelet agents

Adenosine diphosphate (ADP)-mediated platelet aggregation is signaled through two distinct G protein-coupled receptors (GPCR) on the platelet surface: P2Y12 and P2Y1. Blocking P2Y12 receptor is a clinically well-validated strategy for antithrombotic therapy. P2Y1 antagonists have been shown to have the potential to provide equivalent antithrombotic efficacy as P2Y12 inhibitors with reduced bleeding in preclinical animal models. We have previously reported the discovery of a potent and orally bioavailable P2Y1 antagonist, 1. This paper describes further optimization of 1 by introducing 4-aryl groups at the hydroxylindoline in two series. In the neutral series, 10q was identified with excellent potency and desirable pharmacokinetic (PK) profile. It also demonstrated similar antithrombotic efficacy with less bleeding compared with the known P2Y12 antagonist prasugrel in rabbit efficacy/bleeding models. In the basic series, 20c (BMS-884775) was discovered with an improved PK and liability profile over 1. These results support P2Y1 antagonism as a promising new antiplatelet target.

4-Benzothiazole-7-hydroxyindolinyl diaryl ureas are potent P2Y1 antagonists with favorable pharmacokinetics: low clearance and small volume of distribution

Current antithrombotic discovery efforts target compounds that are highly efficacious in thrombus reduction with less bleeding liability than the standard of care. Preclinical data suggest that P2Y1 antagonists may have lower bleeding liabilities than P2Y12 antagonists while providing similar antithrombotic efficacy. This article describes our continuous SAR efforts in a series of 7-hydroxyindolinyl diaryl ureas. When dosed orally, 4-trifluoromethyl-7-hydroxy-3,3-dimethylindolinyl analogue 4 was highly efficacious in a model of arterial thrombosis in rats with limited bleeding. The chemically labile CF3 group in 4 was then transformed to various groups via a novel one-step synthesis, yielding a series of potent P2Y1 antagonists. Among them, the 4-benzothiazole-substituted indolines had desirable PK properties in rats, specifically, low clearance and small volume of distribution. In addition, compound 40 had high i.v. exposure and modest bioavailability, giving it the best overall profile.

2-Amino-1,3,4-thiadiazoles in the 7-hydroxy-N-neopentyl spiropiperidine indolinyl series as potent P2Y1 receptor antagonists

Blockade of the P2Y1 receptor is important to the treatment of thrombosis with potentially improved safety margins compared with P2Y12 receptor antagonists. Investigation of a series of urea surrogates of the diaryl urea lead 3 led to the discovery of 2-amino-1,3,4-thiadiazoles in the 7-hydroxy-N-neopentyl spiropiperidine indolinyl series as potent P2Y1 receptor antagonists, among which compound 5a was the most potent and the first non-urea analog with platelet aggregation (PA) IC50 less than 0.5 μM with 10 μM ADP. Several 2-amino-1,3,4-thiadiazole analogs such as 5b and 5f had a more favorable pharmacokinetic profile, such as higher Ctrough, lower Cl, smaller Vdss, and similar bioavailability compared with 3.

Identification of 1-{2-[4-chloro-1'-(2,2-dimethylpropyl)-7-hydroxy-1,2-dihydrospiro[indole-3,4'-piperidine]-1-yl]phenyl}-3-{5-chloro-[1,3]thiazolo[5,4-b]pyridin-2-yl}urea, a potent, efficacious and orally bioavailable P2Y(1) antagonist as an antiplatelet agent

Spiropiperidine indoline-substituted diaryl ureas had been identified as antagonists of the P2Y1 receptor. Enhancements in potency were realized through the introduction of a 7-hydroxyl substitution on the spiropiperidinylindoline chemotype. SAR studies were conducted to improve PK and potency, resulting in the identification of compound 3e, a potent, orally bioavailable P2Y1 antagonist with a suitable PK profile in preclinical species. Compound 3e demonstrated a robust antithrombotic effect in vivo and improved bleeding risk profile compared to the P2Y12 antagonist clopidogrel in rat efficacy/bleeding models.

Conformationally constrained ortho-anilino diaryl ureas: discovery of 1-(2-(1'-neopentylspiro[indoline-3,4'-piperidine]-1-yl)phenyl)-3-(4-(trifluoromethoxy)phenyl)urea, a potent, selective, and bioavailable P2Y1 antagonist

Preclinical antithrombotic efficacy and bleeding models have demonstrated that P2Y1 antagonists are efficacious as antiplatelet agents and may offer a safety advantage over P2Y12 antagonists in terms of reduced bleeding liabilities. In this article, we describe the structural modification of the tert-butyl phenoxy portion of lead compound 1 and the subsequent discovery of a novel series of conformationally constrained ortho-anilino diaryl ureas. In particular, spiropiperidine indoline-substituted diaryl ureas are described as potent, orally bioavailable small-molecule P2Y1 antagonists with improved activity in functional assays and improved oral bioavailability in rats. Homology modeling and rat PK/PD studies on benchmark compound 3l will also be presented. Compound 3l was our first P2Y1 antagonist to demonstrate a robust oral antithrombotic effect with mild bleeding liability in the rat thrombosis and hemostasis models.

Potent P2Y1 urea antagonists bearing various cyclic amine scaffolds

A number of new amine scaffolds with good inhibitory activity in the ADP-induced platelet aggregation assay have been found to be potent antagonists of the P2Y1 receptor. SAR optimization led to the identification of isoindoline 3c and piperidine 4a which showed good in vitro binding and functional activities, as well as improved aqueous solubility. Among them, the piperidine 4a showed the best overall profile with favorable PK parameters.

New azole antagonists with high affinity for the P2Y(1) receptor

Five-membered-ring heterocyclic urea mimics have been found to be potent and selective antagonists of the P2Y1 receptor. SAR of the various heterocyclic replacements is presented, as well as side-chain SAR of the more potent thiadiazole ring system which leads to thiadiazole 4c as a new antiplatelet agent.

Discovery of diarylurea P2Y(1) antagonists with improved aqueous solubility

Preclinical data suggests that P2Y1 antagonists, such as diarylurea compound 1, may provide antithrombotic efficacy similar to P2Y12 antagonists and may have the potential of providing reduced bleeding liabilities. This manuscript describes a series of diarylureas bearing solublizing amine side chains as potent P2Y1 antagonists. Among them, compounds 2l and 3h had improved aqueous solubility and maintained antiplatelet activity compared with compound 1. Compound 2l was moderately efficacious in both rat and rabbit thrombosis models and had a moderate prolongation of bleeding time in rats similar to that of compound 1.

Discovery of 2-(phenoxypyridine)-3-phenylureas as small molecule P2Y1 antagonists

Two distinct G protein-coupled purinergic receptors, P2Y1 and P2Y12, mediate ADP-driven platelet activation. The clinical effectiveness of P2Y12 blockade is well established. Recent preclinical data suggest that P2Y1 and P2Y12 inhibition provide equivalent antithrombotic efficacy, while targeting P2Y1 has the potential for reduced bleeding liability. In this account, the discovery of a 2-(phenoxypyridine)-3-phenylurea chemotype that inhibited ADP-mediated platelet aggregation in human blood samples is described. Optimization of this series led to the identification of compound 16, 1-(2-(2-tert-butylphenoxy)pyridin-3-yl)-3-4-(trifluoromethoxy)phenylurea, which demonstrated a 68 ± 7% thrombus weight reduction in an established rat arterial thrombosis model (10 mg/kg plus 10 mg/kg/h) while only prolonging cuticle and mesenteric bleeding times by 3.3- and 3.1-fold, respectively, in provoked rat bleeding time models. These results suggest that a P2Y1 antagonist could potentially provide a safe and efficacious antithrombotic profile.

From cholera to burns: a role for oral rehydration therapy

According to the practice guidelines of the American Bum Association on burn shock resuscitation, intravenous (i.v.) fluid therapy is the standard of care for the replacement of fluid and electrolyte losses in burn injury of > or = 20% of the total body surface area. However, in mass burn casualties, i.v. fluid resuscitation may be delayed or unavailable. Oral rehydration therapy (ORT), which has been shown to be highly effective in the treatment of dehydration in epidemics of cholera, could be an alternate way to replace fluid losses in burns. A prospective case series of three patients was carried out as an initial step to establish whether oral Ceralyte 90 could replace fluid losses requiring i.v. fluid therapy in thermal injury. The requirement of the continuing i.v. fluid therapy was reduced by an average of 58% in the first 24 hours after the injury (range 37-78%). ORT may be a feasible alternative to i.v. fluid therapy in the resuscitation of burns. It could also potentially save many lives in mass casualty situations or in resource-poor settings where i.v. fluid therapy is not immediately available. Further studies are needed to assess the efficacy of this treatment and to determine whether the present formulations of ORT for cholera need modification.

Malignant superior vena cava syndrome presenting after trauma

A 41-year-old man was brought to the ED after a motor vehicle crash. On presentation, he demonstrated symptoms compatible with superior vena cava (SVC) syndrome, including extreme dyspnea, face and neck cyanosis and facial swelling. A chest tube was inserted and drained large amounts of sanguineous fluid. An exploratory thoracotomy revealed an extensive tumour encasing the SVC and the hilum. Biopsy confirmed the diagnosis of T-cell lymphoma. The most common cause of SVC syndrome is malignant disease, with bronchogenic carcinoma and lymphoma being most frequent. Review of the literature uncovered only a few anecdotal reports of traumatic SVC syndrome. There are no previous reported cases of malignant SVC syndrome presenting in association with trauma.

Biomarker optimization to track the antithrombotic and hemostatic effects of clopidogrel in rats

We determined the dose response of the ADP antagonist clopidogrel (0.3-50 mg/kg p.o.) in rat models of thrombosis and provoked bleeding and correlated these activities to ex vivo platelet activation. Carotid artery thrombosis was induced by FeCl(2). Bleeding time was measured by mesenteric vessel puncture and renal cortex or cuticle incision. Platelet biomarkers included standard ADP-induced aggregation, P2Y(12) receptor occupancy, and phosphorylation of vasodilator-stimulated phosphoprotein. Clopidogrel decreased thrombus weight up to 78%, caused maximal prolongation of cuticle and mesenteric bleeding, but had little effect on renal bleeds. Due to the steep mesenteric dose response, further comparisons concentrated on cuticle bleeding. The half-maximal inhibitory dose (ED(50)) for thrombus reduction was 2.4 +/- 0.4 mg/kg, with 10 mg/kg providing optimal blood flow preservation and thrombus reduction. The ED(50) for bleeding was 10.5 +/- 3.4 mg/kg. Increased bleeding was intermediate (3-fold) at 10 mg/kg and maximal (6-fold) at 30 mg/kg. All biomarkers were affected, but with differing sensitivity. ED(50)s for peak platelet aggregation to 10 microM ADP (11.9 +/- 0.4 mg/kg) and the vasodilator-stimulated phosphoprotein index (16.4 +/- 1.3 mg/kg) approximated the higher ED(50) for bleeding. ED(50)s for ligand binding (3.0 +/- 0.3 mg/kg) and late aggregation (5.1 +/- 0.4 mg/kg) better matched the lower ED(50) for antithrombotic activity. Aspirin exerted lesser effects on bleeding (42-70% increase in all models) and thrombosis (24% inhibition). In summary, antithrombotic doses of clopidogrel have limited effects on bleeding and standard measures of platelet aggregation. Other biomarkers may be more sensitive for tracking antithrombotic efficacy.

At second glance: employers and employees with learning disabilities in the Americans with Disabilities Act era

The impact of the Americans with Disabilities Act (ADA) of 1990 on the American workplace is examined. The findings of a previous study (Gerber, 1992) on employer knowledge about learning disabilities are compared to current findings. Important themes and employer beliefs and practices that were consistent in employer responses are described. Although employers are continuing to make efforts to comply with the regulations of the ADA, they still have relatively little knowledge or experience with it in terms of learning disabilities.

A linear hexapeptide somatostatin antagonist blocks somatostatin activity in vitro and influences growth hormone release in rats

Somatostatin (SRIF) is the main inhibitory peptide regulating growth hormone (GH) secretion. It has been difficult to establish the role of endogenous SRIF release in the absence of pure SRIF antagonists. Although several SRIF antagonists have recently been described, none have been shown to possess in vivo activity in the absence of added SRIF. Here, an SRIF antagonist with no detectable agonist activity has been identified from a synthetic combinatorial hexapeptide library containing 6.4 x 10(7) unique peptides. Each peptide in the library is amino-terminally acetylated and carboxyl-terminally amidated and consists entirely of D-amino acids. A SRIF-responsive yeast growth assay was used as a primary screening tool, and cAMP accumulation, competitive binding, and microphysiometry also were used to confirm and further characterize SRIF antagonist activity. The hexapeptide library was screened in stepwise iterative fashion to identify AC-178,335, a pure SRIF antagonist of the sequence Ac-hfirwf-NH2. This D-hexapeptide bound SRIF receptor type 2 with an affinity constant (Ki) of 172 +/- 12 nM, blocked SRIF inhibition of adenylate cyclase in vitro (IC50 = 5.1 +/- 1.4 microM), and induced GH release when given alone (50 micrograms intravenously) to anesthetized rats with or without pretreatment with a long-acting SRIF agonist.

Investigation of growth hormone releasing hormone receptor structure and activity using yeast expression technologies

Growth hormone releasing hormone (GHRH) is the positive regulator of growth hormone synthesis and secretion in the anterior pituitary. The peptide confers activity by binding to a seven transmembrane domain G protein-coupled receptor. Signal transduction proceeds through subsequent G alpha s stimulation of adenylyl cyclase. To investigate ligand/receptor and receptor/G protein associations, the human GHRH receptor was expressed in a modified S. cerevisiae strain which allows for facile measurement of receptor activity by cell prototrophy mediated by a reporter gene coupled to the yeast pheromone response pathway. GHRH-dependent signal activation in this system required the substitution of yeast G alpha protein with proteins containing C-terminal regions of G alpha s. A D60G variant (analogous to the little mouse mutation) of the receptor failed to respond to agonist. In parallel studies, GHRH29 and the N-terminal extracellular region of the receptor were expressed as Gal4 fusion proteins in a 2-hybrid assay. A specific interaction between these proteins was readily observed. The D60G mutation was engineered into the receptor fusion protein. This protein failed to interact with the ligand fusion, confirming the specificity of the association between unmodified proteins. These two yeast expression technologies should prove invaluable in additional structure/activity analyses of this ligand/receptor pair as well as other peptide ligands and receptors.

ORK1, a potassium-selective leak channel with two pore domains cloned from Drosophila melanogaster by expression in Saccharomyces cerevisiae

A K+ channel gene has been cloned from Drosophila melanogaster by complementation in Saccharomyces cerevisiae cells defective for K+ uptake. Naturally expressed in the neuromuscular tissues of adult flies, this gene confers K+ transport capacity on yeast cells when heterologously expressed. In Xenopus laevis oocytes, expression yields an ungated K(+)-selective current whose attributes resemble the "leak" conductance thought to mediate the resting potential of vertebrate myelinated neurons but whose molecular nature has long remained elusive. The predicted protein has two pore (P) domains and four membrane-spanning helices and is a member of a newly recognized K+ channel family. Expression of the channel in flies and yeast cells makes feasible studies of structure and in vivo function using genetic approaches that are not possible in higher animals.

Chronic copper toxicosis presenting as liver failure in an Australian child

A 20 month old Caucasian male child, after a five week illness, developed liver failure which was successfully treated by liver transplantation. The explanted liver had a histology identical to that seen in Indian childhood cirrhosis and its copper content was increased tenfold. Water used to prepare the child's milk feeds came from a bore via copper conduits and at times contained 120 mumol/l of copper, eight times the recommended maximum for human consumption. Because non-Indian cases of Indian childhood cirrhosis associated with excess copper ingestion are increasingly being recognised, and as early treatment can restore normal liver morphology, we support the use of the previously suggested alternative term for this condition, ie; 'copper-associated liver disease in childhood'. Measurement of hepatic copper concentrations in all children less than six years of age who develop hepatic failure of unknown cause will increase its recognition. On diagnosis sources of increased dietary copper should be investigated to ensure that younger siblings are not similarly exposed.

Pharmacological characterization of the rat A2a adenosine receptor functionally coupled to the yeast pheromone response pathway

The rat A2a adenosine receptor, a G protein-coupled receptor, was functionally expressed in the yeast Saccharomyces cerevisiae. High affinity binding sites for A2a adenosine agonists were detected in yeast membranes containing the endogenous Grx protein Gpa1. Agonist saturation binding isotherms using [3H]5'-N-ethylcarboxamidoadenosine indicated that the A2a adenosine receptor expressed in yeast cell membranes displays pharmacological properties equivalent to those observed when the receptor is expressed in human embryonic kidney 293 cell membranes. The rank order of potency of various agonists in [3H]5'-N-ethylcarboxamidoadenosine competition binding assays performed with yeast cell membranes was comparable to that seen for the receptor expressed in mammalian cell membranes. Adenosine agonist-dependent growth response of yeast strains expressing the A2a adenosine receptor was elicited via activation of the yeast pheromone-response pathway. Induction of a pheromone-responsive FUS1-HIS3 reporter gene in far1 his3 cells permits cell growth in medium lacking histidine. The sensitivity of the bioassay was increased by deletion of the STE2 gene, which encodes the yeast alpha-mating pheromone receptor. The growth response was dose dependent, and agonists of varying affinities displayed a rank order of potency comparable to that observed in competition binding assays. Agonist-activated growth assays performed in liquid culture gave ED50 values for various adenosine agonists consistent with reported Kd alpha values. Yeast strains expressing a single receptor/G protein complex will be useful as a model system for the study of receptor/G protein interactions in vivo.

Identification and characterization of novel somatostatin antagonists

The study of the five somatostatin receptor subtypes (SSTx, where x is the subtype number) has been hampered by the lack of high affinity antagonists. Potent and selective antagonists would increase our understanding of SST structure, function, and regulation. In this study, the identification of novel disulfide-linked cyclic octapeptide antagonists of somatostatin is described. The antagonists contain a core structure of a DL-cysteine pair at positions 2 and 7 of the peptides. Substitution of a D-cysteine at position 2 with an L-cysteine converts the full antagonist into a full agonist. All somatostatin receptor subtypes are coupled to inhibition of adenylate cyclase. The functional properties of these peptides have been determined in radioligand binding assays, in functional coupling of the SST2 subtype to yeast pheromone response pathway, and in cAMP accumulations. One peptide antagonist [Ac-4-NO2-Phe-c(D-Cys-Tyr-D-Trp-Lys-Thr-Cys)-D-Tyr-NH2] displays a binding affinity to SST2 comparable with that observed for the native hormone (Ki = 0.2 nM) and reverses somatostatin-mediated inhibition of cAMP accumulation in rat somatomammotroph GH4C1 cells, cells transfected with the SST2 and SST5 subtypes, as well as somatostatin-stimulated growth of yeast cells expressing the SST2 subtype. This class of somatostatin antagonists, which are the first to be described, should be useful for determination of somatostatin's diverse functions in vivo and in vitro.

Functional coupling of a mammalian somatostatin receptor to the yeast pheromone response pathway

A detailed analysis of structural and functional aspects of G-protein-coupled receptors, as well as discovery of novel pharmacophores that exert their effects on members of this class of receptors, will be facilitated by development of a yeast-based bioassay. To that end, yeast strains that functionally express the rat somatostatin receptor subtype 2 (SSTR2) were constructed. High-affinity binding sites for somatostatin ([125I-Tyr-11]S-14) comparable to those in native tissues were detected in yeast membrane extracts at levels equivalent to the alpha-mating pheromone receptor (Ste2p). Somatostatin-dependent growth of strains modified by deletion of genes encoding components of the pheromone response pathway was detected through induction of a pheromone-responsive HIS3 reporter gene, enabling cells to grow on medium lacking histidine. Dose-dependent growth responses to S-14 and related SSTR2 subtype-selective agonists that were proportional to the affinity of the ligands for SSTR2 were observed. The growth response required SSTR2, G alpha proteins, and an intact signal transduction pathway. The sensitivity of the bioassay was affected by intracellular levels of the G alpha protein. A mutation in the SST2 gene, which confers supersensitivity to pheromone, was found to significantly enhance the growth response to S-14. In sst2 delta cells, SSTR2 functionally interacted with both a chimeric yeast/mammalian G alpha protein and the yeast G alpha protein, Gpa1p; to promote growth. These yeast strains should serve as a useful in vivo reconstitution system for examination of molecular interactions of the G-protein-coupled receptors and G proteins.

Paraquat and diquat interference in the analysis of creatinine by the Jaffé reaction

Paraquat and diquat were shown to interfere significantly in the measurement of plasma creatinine by the alkaline picrate (Jaffé) reaction in a young man who ingested a massive dose of a mixture of the 2 herbicides. It is likely that these bipyridylium compounds react in a manner similar but at different rates compared with creatinine in the Jaffé reaction.

Causes of higher in-hospital mortality in women than in men after acute myocardial infarction

Clinical, laboratory and cardiac catheterization parameters were reviewed in 355 men and 155 women hospitalized at a tertiary care referral center between February 1987 and December 1991 to analyze why women have a higher in-hospital mortality rate than do men after acute myocardial infarction. Hospital mortality was 21.4% in women and 12.1% in men (p = 0.007). In comparison with men, women were older (63.3 +/- 11.9 vs 60.5 +/- 12.6 years; p = 0.023), had more systemic hypertension (46.5 vs 34.4%; p = 0.001) and higher serum total cholesterol levels (211 +/- 51 vs 197 +/- 49 mg/dl; p = 0.0015), sought medical care later (8.9 vs 5.3 hours; p = 0.026), were referred later (47.7 vs 43.7 hours; p = 0.063) and had more shock (34.8 vs 24.2%; p = 0.013). Logistic regression analysis revealed 5 variables predictive of hospital mortality; age > 65 years, diabetes, shock, non-Q-wave infarction, and not undergoing cardiac catheterization. Gender was of borderline significance in predicting hospital mortality. Cardiac catheterization, performed in 88% of women and 87% of men, showed similar rates of 1-, 2- and 3-vessel disease, and similar characteristics of the infarction-related artery. The differences in hospital mortality between men and women are due to a combination of pre- and in-hospitalization factors in women. The excess mortality is not due to differences in disease severity as evaluated by cardiac catheterization information.

When academic assistance is not enough: addressing the mental health issues of adolescents and adults with learning disabilities

This article focuses on an answer to a critical question for adolescents and adults with learning disabilities: How can professionals assist students with learning disabilities who have psychosocial issues that appear to be affecting their academic progress and life adjustment? Inherent in this inquiry are other, equally important issues, such as: How do learning disabilities service providers know when to involve other service providers? What are the steps in referring a student for further assistance with different mental health issues? When are team interventions necessary? How are team interventions conducted in either secondary or postsecondary settings? How should learning disabilities service providers establish the boundaries of their professional expertise and/or responsibilities to adequately meet the needs of individuals with learning disabilities? This article illustrates answers to these questions by providing examples of interventions and case studies from two federally funded research/demonstration projects at the University of Minnesota: the Learning Disabilities Transition Project and Project Extra. The authors describe theoretical models for mental health services that address the psychosocial issues frequently encountered in academic or vocational settings. Recommendations are also included that discuss how the models can be personalized to fit the reader's home institution or agency.

Lack of survival advantage in patients with advanced squamous cell carcinomas of the oral cavity receiving neoadjuvant chemotherapy prior to local therapy, despite achieving an initial high clinical complete remission rate

Subset analyses have been performed on 50 patients with squamous cell carcinomas of the oral cavity from our earlier series of 208 patients with advanced, previously untreated head and neck tumors (J Clin Oncol 1986;4:1340-7). Forty patients (80%) responded to two initial courses of Schedule A chemotherapy. Side effects were minimal. After definitive local therapy the final complete remission (CR) rate was 76%. Neither chemotherapy response, nor achievement of final CR was significantly affected by stage, T or N status, sex, or histologic grade. With a median follow-up of 11.6 years, the overall 10-year survival rate was 25%. Multivariate analysis indicated that both age, i.e., < 50 years (p = .004) and achievement of a final CR (p = .002) were significant factors for improved survival. Median survival for all patients was only 21 months and for those in final CR 30 months. These survival figures were all significantly lower than those of similarly treated patients with laryngeal or nasopharyngeal tumors, illustrating that all patients with head and neck tumors achieving a final clinical CR do not automatically have improved survival. These results emphasize the need for randomized trials, with sufficient numbers to identify optimal treatment strategies for tumors at specific sites within the head and neck region.

The role of adjuvant chemotherapy in the treatment of advanced head and neck cancer

The role of chemotherapy in the multidisciplinary treatment of advanced squamous cell carcinoma of the head and neck remains to be defined. Uncontrolled adjuvant studies integrating chemotherapy with local therapies utilizing a 'sequential' or 'simultaneous' strategy have indicated that high response rates to initial chemotherapy and high complete remission rates are achievable. Both these factors appear to predict for improved survival. Unfortunately results of randomized, controlled studies generally have not confirmed any major overall survival advantage. However, these trials clearly failed to utilize optimal therapies: suboptimal trials yield suboptimal results. Encouraging data from large uncontrolled studies have now provided critical information regarding optimal trial design; a) Since primary tumor site has proved a significant predictive factor for response to treatment and survival, future trials must include sufficient numbers of patients for detailed site-by-site analyses, and b) radical surgery may be omitted without compromising survival by using initial chemotherapy followed by radiotherapy for advanced laryngeal cancer.

An automated approach to a residency log

A highly automated system that meets the Residency Review Committee (RRC) requirements for documenting residents' clinical activity has been developed using readily available computer hardware and a specialized software package. Once in place, the system is relatively unobtrusive and requires only two to four hours a month of technical support but no additional clerical or secretarial time to operate. The costs of the system are primarily those it takes to make it operational. Maintenance costs are low. Regular monitoring of residents' clinical activity has had a salutary effect on program planning and enhanced the program's ability to meet RRC guidelines.

Biomimetic oxidation of nonphenolic lignin models by Mn(III): new observations on the oxidizability of guaiacyl and syringyl substructures

Mn(III) is a one-electron oxidant, produced in vivo by the Mn peroxidases of white-rot fungi, and thought to be involved in lignin degradation by these organisms. However, Mn(III) has not been shown to oxidize the major nonphenolic substructures of lignin under mild conditions. We have used Mn(III) acetate as a biomimetic model for enzymatically generated Mn(III), and report that low concentrations of this oxidant suffice to oxidize nonphenolic lignin models at physiological temperatures and pH values. Under these conditions, the monomeric lignin model veratryl alcohol was oxidized to veratraldehyde, and the diarylpropane model 1-(3,4-dimethoxyphenyl)-2-phenylpropanol was oxidatively cleaved to veratraldehyde, 1-phenylethanol, and acetophenone. In an attempt to identify other lignin models that might be oxidized by Mn(III) more rapidly, we compared the rates at which Mn(III) was reduced by two guaiacyl models, veratryl alcohol and 1-(3-methoxy-4-isopropoxyphenyl)ethanol, vs two syringyl models, 3,4,5-trimethoxybenzyl alcohol and 1-(3,5-dimethoxy-4-isopropoxyphenyl)ethanol. The results were the opposite of those predicted: the syringyl models were oxidized slower than the guaiacyl models by Mn(III). To investigate the basis for this unexpected result, we recorded the visible absorption spectra of charge-transfer complexes prepared between each of the lignin models and an electron acceptor, tetracyanoethylene or p-chloranil. The results, in general agreement with the kinetic findings, showed that the nonphenolic syringyl lignin models had higher ionization potentials than the guaiacyl models.

The promising role of safe initial non-cisplatin-containing combination chemotherapy in nasopharyngeal tumors

Twenty patients with previously untreated nasopharyngeal tumors received, as initial treatment, two courses of Schedule A chemotherapy including vincristine, 5-fluorouracil, bleomycin, hydrocortisone, methotrexate, and a folinic acid rescue, prior to definitive radiotherapy. Thirteen patients had Stage IV and seven had Stage III tumors, with nodal involvement in 18 patients (90%). Response to two courses of Schedule A chemotherapy was assessed on day 28, and overall, 18 patients responded. Side effects were minimal. Following radiotherapy 17 patients achieved a clinical complete remission. Durations of response ranged from 6 to 95+ months (median 40 months) and of survival from 8 to 95+ months (median 53 months). This chemotherapy protocol should be more widely evaluated as initial treatment in nasopharyngeal carcinomas since the 90% chemotherapy response rate and, after radiotherapy, 85% clinical complete remission rate was accomplished with minimal toxicity and interference with patients' quality of life and resulted in median overall survival figures of approximately four years.

Importance of primary site in assessing chemotherapy response and 7-year survival data in advanced squamous-cell carcinomas of the head and neck treated with initial combination chemotherapy without cisplatin

Two hundred eight patients with advanced head and neck squamous-cell carcinomas were treated between 1975 and 1982 with schedule A chemotherapy containing vincristine, bleomycin, methotrexate, 5-fluorouracil, and hydrocortisone administered over 24 hours followed by a folinic acid rescue. Chemotherapy was administered as initial treatment on days 1 and 14 before "curative" local therapy. Toxicity was minimal and patient compliance was 100%. Chemotherapy response was assessed on day 28 in 200 patients: 132 (66%) had an objective response and 68 (34%) were judged to be nonresponders. The complete remission (CR) rate following local therapy was significantly greater in chemotherapy responders (78%) than nonresponders (49%) (P less than .001). Overall median survival figures were 32 months for all patients, 37 months for all chemotherapy responders, and 69 months for all patients achieving CR. Analysis by tumor site showed that oral cavity or nasopharyngeal tumors responded well to initial chemotherapy (P less than .05 and P less than .01) compared with all other sites. This high response rate was not necessarily associated with increased survival, since the median survival of chemotherapy responders for oral cavity lesions was only 22 months, although in nasopharyngeal tumors, median survival figures were 64 months. Furthermore, the longest median survival duration of 69 months was observed in patients with laryngeal tumors, although these had a lower response rate (61%) to initial chemotherapy. Therefore, response to initial chemotherapy is not automatically a favorable prognostic sign. Survival figures appear markedly influenced by tumor site.

24-hour combination chemotherapy without cisplatin in patients with recurrent or metastatic head and neck cancer

Sixty-three patients with advanced histologically proven squamous cell carcinomas of the head and neck, considered untreatable other than by chemotherapy, received a combination of vincristine, bleomycin, methotrexate, 5-fluorouracil, and hydrocortisone administered over 24 hours, followed by a folinic acid rescue, every 3 weeks. Fifty-seven patients had received prior radiotherapy and 78% of recurrences were within the radiation field. Sixty-one patients were assessable for response to chemotherapy and 25 (41%) achieved objective responses. Side effects from 167 courses of chemotherapy were minimal and were present only in 38% of patients. There were no cases of bone marrow depression and no drug-induced deaths. Patient compliance was 98%. Chemotherapy responders had a longer median duration of survival of 11.9 months (with four patients still alive at 10, 22, 30, and 90 months) compared with 4.96 months for nonresponders (with two patients alive at 7 and 15 months), p less than 0.001. Ten of 24 chemotherapy responders went on to surgery and eight achieved a complete remission (CR), while only 6/36 nonresponders underwent salvage surgery and all became disease-free. Patients achieving a complete remission had improved survival (median 24.5 months). The presence of metastatic disease was a poor prognostic sign; only 8/30 (27%) responded to chemotherapy and none subsequently achieved complete remission. This safe drug protocol appears to benefit only a small subset of patients, namely those who respond to chemotherapy rendering their tumors operable, but is of no general value in this group of previously irradiated patients since 92% of all patients treated were dead at 2 years.

Treatment of advanced squamous cell carcinomas of the head and neck with initial combination chemotherapy prior to surgery and/or radiotherapy: five-year survival data

One hundred and thirty-nine patients with advanced head and neck cancer were treated with a combination of vincristine, bleomycin, methotrexate with a folinic acid rescue, 5-fluorouracil and hydrocortisone given over 24 hours, as initial therapy on days one and 14 prior to conventional local therapy on day 28. One hundred and thirty-six patients were assessed for chemotherapy response on day 28. Ninety-one patients (67 per cent) had an objective response and 45 (33 per cent) were classed as non-responders, although 13 had a minimal (20-30 per cent) response. The complete remission rate following local therapy was significantly greater in chemotherapy responders (76 per cent) than in nonresponders (54 per cent) p less than 0.05. Toxicity was minimal, provided standard medical precautions were observed, and 87 patients (63 per cent) reported no side-effects. There was 100 per cent patient compliance. Sex or histological grade did not significantly influence response to chemotherapy. Oral cavity or nasopharyngeal tumours responded better than other sites (p less than 0.05). Patients under 49 were more likely to respond to chemotherapy than older patients (p less than 0.01). Survival data are available for a mean follow-up time of 48 months (range 12-78 months). Chemotherapy responders have a longer median survival than non-responders, 33 versus 20 months (p less than 0.05). Patients who achieve a complete remission after local therapy live significantly longer than those with residual disease, median durations of survival being 52.4 and 7.8 months respectively (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

An experimentally based safe method of administering intensive cancer chemotherapy. Prospects for increased survival in patients with 'solid' tumours during the next decade

A clinically proven experimentally based method of administering intensive combination chemotherapy, which is much safer than methods used in the past, has been developed over the past 13 years. Clinical studies of several different tumour types over several thousand treatment cycles have confirmed the validity of this approach. The implications of this new method of administering chemotherapy to patients with advanced disease are discussed and its potential for improving the 'cure' rates for certain common 'solid' tumours such as breast, small-cell lung, bladder, prostate and ovarian carcinomas and squamous cell carcinomas of the head and neck is outlined.