Preclinical antitumor activity of CI-994

CI-994 [aka: acetyldinaline; PD 123654; 4-acetylamino-N-(2'aminophenyl)-benzamide] (Figure 1) is a novel antitumor agent with a unique mechanism of action. It is the acetylated metabolite of dinaline, a compound previously identified as having cytotoxic and cytostatic activity against several murine and human xenograft tumor models. CI-994 had activity against 8/8 solid tumors tested (log cell kills at the highest non-toxic dose): pancreatic ductal adenocarcinoma #02 (4.7); pancreatic adenocarcinoma #03 (3.0; 1/6 cures); colon adenocarcinoma #38 (1.6); colon adenocarcinoma #51/A (1.1); mammary adenocarcinoma #25 (1.7); mammary adenocarcinoma #17/ADR (0.5); Dunning osteogenic sarcoma (4.0); and the human prostate carcinoma LNCaP (1.2). CI-994 had the same spectrum of activity in vivo as dinaline. It also behaved similarly in schedule comparison/toxicity trials. Prolonged administration with lower drug doses was more effective than short-term therapy at higher individual doses. If doses were kept between 40 and 60 mg/kg/injection, prolonged administration (> 50 days) was tolerated with no gross toxicity. Doses > or = 90 mg/kg/injection caused lethality after 4-5 days of administration. The maximum tolerated total dose was also increased with smaller individual doses administered for prolonged intervals. Clinical Phase I trials are ongoing with this agent.

The Cooperative Familial Registry for Breast Cancer Studies: design and first year recruitment rates in Ontario

The Ontario Familial Breast Cancer Registry (OFBCR) is one of six international sites of the Cooperative Familial Registry for Breast Cancer Studies collecting family history, epidemiologic information, and blood samples from families (with various patterns of familial risk) for the purpose of studying the etiology of breast cancer. To invite 2361 female breast cancer patients residing in Ontario to take part in the Registry, a package was sent that included a Family History Questionnaire. Several variations of mailing and follow-up strategies were employed. Overall, the response rate was 67%. The best response (74%) was achieved by following up our introductory package of information with a postcard 10 days later and a telephone call several weeks thereafter. Given the design of the project, which involves a considerable commitment on the part of both patients and their family members, we are impressed by the positive response of these women.

Proper use of skin adhesives for wound repair

PURPOSE

To describe the proper application of tissue adhesive for wound closure in the clinical setting.

DATA SOURCES

Product information and clinical experience of the author.

CONCLUSIONS

A thin film of adhesive that extends at least one-half centimeter on each side of the opposed wound edges provides the best coverage. Avoid seepage into the wound and runoff onto surrounding tissue to prevent complications.

IMPLICATIONS FOR PRACTICE

Proper application assures the best results. Patient information is provided to assure adequate healing.

Does vestibular habituation still have a place in the treatment of benign paroxysmal positional vertigo?

Particle repositioning procedures such as the Epley manoeuvre have become popular in the management of benign paroxysmal positional vertigo (BPPV) at the expense of more traditional therapies such as vestibular habituation. We prospectively analysed the response of consecutive patients presenting with BPPV to treatment with vestibular habituation exercises using a symptom score sheet before and after treatment. This same patient group was then followed up, on average three years, eight months after discharge, to determine their long-term response to treatment. The results of the study demonstrated an excellent short-term response rate to treatment but a high level of recurrence after discharge. Most patients who experienced further symptoms following discharge were however self-reliant and were able to return to their habituation exercises without the need for further medical input. The aim in the management of these patients must be to provide long-term self reliance as well as short-term cure and it may be that this has not yet been well demonstrated with the Epley manoeuvre. It must also be remembered that particle repositioning manoeuvres cannot be used in all patients for example those who suffer with cervical or thoracic spine pathology and that some will fail to respond at all. We believe that vestibular habituation retains a useful role in the treatment of BPPV.

Investigation of chromosome 17q as a locus for human essential hypertension in African Caribbeans

Essential hypertension is a major risk factor for cardiovascular disease in humans, and originates from both genetic and environmental factors. Data from animal and more recently human studies have indicated the presence of a gene influencing blood pressure on human chromosome 17. This study tested for linkage of markers located on chromosome 17q to essential hypertension in African Caribbean hypertensive families. No support of linkage was found between the markers studied and hypertension, however only genes of a lamda sib value of less than 1.8 could be excluded Journal of Human Hypertension (2000) 14, 385-387

Dissemination of responsible service of alcohol initiatives to rugby league clubs

OBJECTIVES

To determine the acceptability of intervention strategies that increase the responsible service of alcohol by non-metropolitan rugby league clubs.

METHOD

Rugby league clubs were provided an information kit and advice by local public health workers, police and a lead agency regarding their responsible service of alcohol practices. Rugby League clubs and public health workers completed an acceptability survey at the conclusion of the study.

RESULTS

Data were collected from 160 contactable clubs (100% consent) and 12 of 14 participating public health workers. Almost all clubs reported of contact with the lead agency, public health workers and police to be acceptable. Fifty-nine percent of clubs reported contact with public health workers to be useful. One-third of the public health workers considered that they were not the most suitable professional group to be involved in delivering the intervention.

CONCLUSIONS

In spite of a suggested culture of harmful alcohol consumption among rugby league participants and spectators, non-metropolitan rugby league clubs appear receptive to public health strategies that increase their responsible service of alcohol.

IMPLICATIONS

The ability of the public health sector to meet this opportunity appears limited, and may require additional strategies to increase the capacity of public health workers to develop/deliver inter-sectorial interventions in this setting.

Reactions of pholasin with peroxidases and hypochlorous acid

The ability of myeloperoxidase (MPO) and horseradish peroxidase (HRP) to induce chemiluminescence (CL) in Pholasin (Knight Scientific, Plymouth, UK), the photoprotein of the Common Piddock Pholas dactylus, was studied. The oxidation of Pholasin by compound I or II of HRP induced an intense light emission, whereas native HRP showed only a small effect. The luminescence observed upon incubation of Pholasin with native MPO was diminished by preincubation with catalase. Considering the high instability of diluted MPO, it is concluded that traces of hydrogen peroxide in water converted MPO to its active forms, compound I and/or II, which are able to oxidize Pholasin. Indeed, the addition of hydrogen peroxide to a mixture of MPO and Pholasin induced an intense burst of light. This emission was enhanced in degree and duration in the absence of chloride. Hypochlorous acid, the reaction product of Cl(-) and compound I of MPO, was itself able to elicit a luminescent response in Pholasin and this luminescence was strongly inhibited by methionine and taurine. However, both of these HOCl scavengers only slightly reduced the light emission induced by MPO/H(2)O(2) in both the presence or absence of chloride. Thus, hypochlorous acid produced by the MPO/H(2)O(2)/Cl(-) system, under the conditions described in this study, did not contribute to Pholasin luminescence. The Pholasin luminescence elicited by formyl-leucyl-methionyl-phenylalanine (fMLP)-stimulated neutrophils depends both on superoxide anion radicals and higher oxidation states of myeloperoxidase (but not on hypochlorous acid). This is shown by the inhibition of luminescence with superoxide dismutase and potassium cyanide, together with the lack of effect of both methionine and taurine. The luminescence response is about eight times greater in cells stimulated with fMLP/cytochalasin B than with fMLP alone.

1990-2000: progress in determining high blood pressure genes

INTRODUCTION

This article attempts to summarise the genetic research that has taken place during the past decade to determine the identity of genes causing high blood pressure.

METHODS

Candidate gene studies and genome-wide scanning have been the methods primarily employed, and studies have been performed in both experimental models (rats and mice) and human volunteers (sibling-pairs and case-control). Key studies from the past 10 years are discussed, in addition to the congenic strains.

RESULTS

Genome-wide scans and candidate gene studies in both rat and man have generated many chromosomal regions and loci involved in blood pressure regulation. However, much work is still required to fine map the large chromosomal regions found in the genome-wide scans and to isolate variants in candidate genes and prove that they are disease-causing.

CONCLUSIONS

It is anticipated that within the next 5 to 10 years at least one blood pressure susceptibility gene will be identified in rat and possibly some in man. It is hoped that the identification of genes controlling blood pressure will enable investigators to determine physiological/biochemical pathways defective in hypertensive patients. This information may then be utilised to identify specific hypertensive phenotypes, to tailor therapy appropriately for patients and hopefully to develop novel therapeutic agents for hypertension.

The discovery and synthesis of highly potent, A2a receptor agonists

A series of N6,2-disubstituted adenosine analogues have been synthesized and their functional activity measured against A2a and A1 receptors. Examples of compounds with both a lipophilic N6-substituent and amino-functionalized 2-position were highly active at the A2a receptor on the human neutrophil.

Holocene coastal dune initiation in Northumberland and Norfolk, eastern UK: climate and sea-level changes as possible forcing agents for dune initiation

Relative sea-level (RSL) control on dune initiation during the Holocene is examined in the context of chronostratigraphies established from 43 vibracores through dunes and into sub-dune sediments taken from the Northumberland and Norfolk (UK) coasts. The chronology is based on 23 accelerated mass spectroscopy and conventional 14C dates, and 37 infra-red-stimulated luminescence dates. The oldest dunes in Northumberland are c. 4 cal. ka bp with phases of dune development at 2.8 and 1.5–1 ka bp. Most dune deposition is of last millennium age, with a concentration, especially in Norfolk, around 500–200 a bp. The initiation and survival of coastal dune sequences relate to macroscale RSL changes over the last 4 ka. Northumberland dunes reflect a gradient of RSL change from a northern RSL fall (forced regression) through to a southern RSL rise (normal regression through sediment supply). The north Norfolk coast has been dominated by a rising RSL through the Holocene, though associated with a sediment supply sufficient to offset the transgressive tendency and allow normal regressive deposition at numerous positions along the coast over the last 1 ka. It is suggested that the development of Little Ice Age (LIA) dunes in both Norfolk and Northumberland identifies the onset of specific conditions in which intertidal sediment sources were exposed (falling sea-level) to onshore winds (LIA circulation changes), which reflect a brief west North Sea period in dune initiation and deposition rates. A comparison of this consolidated dune chronology with statements of RSL elevation and climate conditions in the last 2.5 ka leads to some recognition of RSL fall preceding major dune building in two phases post 1.5 ka bp and post 0.6 ka bp.

Teaching residents about development and behavior: meeting the new challenge

OBJECTIVE

To determine the teaching methods, materials currently used, and unmet needs for teaching developmental-behavioral pediatrics (DBP) at pediatric training programs in the United States.

DESIGN

Cross-sectional survey of US pediatric residency training programs. The survey questionnaire consisted of 3 instruments: a program director survey, a developmental-behavioral pediatrics survey, and an adolescent medicine survey.

PARTICIPANTS

Survey packets were mailed in January 1997 to 211 programs identified by mailing labels from the Association of Pediatric Program Directors.

RESULTS

Data from 148 programs (70%) completing both the DBP survey and program director survey were analyzed. Ninety-five percent of programs reported a block rotation, and 95% of those stated that the rotation was mandatory. Eighty-seven percent had a formal curriculum. Most programs reported using articles, lecture outlines, and precepting for teaching DBP. Few programs used standardized case-based or computerized materials. Most programs, however, indicated a desire for these materials. Few programs felt that 4 topics were covered adequately: adoption (12%), violence (24%), substance use (28%), and conduct problems (41%). Programs that perceived that they covered these topics adequately were more likely to use written cases as part of their curriculum (Mann-Whitney test, 1373.5; P=.04). Barriers to teaching included lack of adequate faculty, time, money, and curricular resources.

CONCLUSIONS

Pediatric residency programs have made significant gains in mandatory DBP training. However, many programs report a lack of adequate faculty, teaching materials, and methods. Responding programs indicated an interest in case-based materials. This approach may represent an alternative and underutilized resource for teaching DBP.

Transgenic pigs as bioreactors: a comparison of gamma-carboxylation of glutamic acid in recombinant human protein C and factor IX by the mammary gland

The mammary gland of transgenic livestock can be used as a bioreactor for producing complex therapeutic proteins. However, the capacity for making a given post-translational modification upon any given polypeptide is uncertain. For example, the efficiency of gamma-carboxylation of glutamic acid in the amino terminal regions of recombinant human protein C (rhPC) and recombinant human Factor IX (rhFIX) is different at similar expression levels. At an expression level of about 200 microg/ml in the milk of transgenic pigs, rhFIX is highly gamma-carboxylated as indicated by pro-coagulant activity and amino acid sequencing. However, only about 20-35% of rhPC has a native, gamma-carboxyglutamic acid-dependent conformation and anti-coagulant activity. Thus, this work provides an example of apparent differences in substrate specificity between two homologous proteins to the endogenous carboxylase of porcine mammary epithelium which leads to varying degrees of post-translational modification.

An aldose reductase intragenic polymorphism associated with diabetic retinopathy

The polyol pathway has been considered important in the development of diabetes long-term complications. Diabetic patients with microvascular disease have increased gene expression and enzyme activity, which may be due to variants in the aldose reductase gene. An association of an intragenic BamHI polymorphic site with diabetic retinopathy and nephropathy has been suggested, but the BamHI site has not been confirmed. In the current study, long template PCR-RFLP and DNA sequencing were used to ascertain its existence. A single substitution of A to C at 95th nucleotide of intron 8 was identified. This polymorphism was investigated in 164 adolescents with type 1 diabetes in whom diabetic retinopathy was assessed by stereoscopic retinal photography. Both the wild haplotype B and homozygote BB were significantly more common in the adolescents with retinopathy than in those without retinopathy (P = 0.018 and 0.002, respectively). We also confirmed an association between a previously described (CA)n repeat sequence and retinopathy in these adolescents (P < 0.0005). However, there was no association between the two polymorphisms.

Risk factors for recurrent urinary tract infection in preschool children

OBJECTIVE

Children with urinary tract infections (UTI) are at risk of renal scarring which may lead to impaired renal function and hypertension. This study examines the risk factors that predispose to recurrent UTI in children and the role of recurrent UTI in renal scarring.

METHODOLOGY

A group of 290 children under 5 years of age with a first symptomatic UTI were studied. Micturating cystourethrogram and dimercaptosuccinic acid (DMSA) renal scintigraphy were performed at entry, and DMSA was repeated 1 year later. Two hundred and sixty-one children (90%) were followed up at 1 year.

RESULTS

There were 46 confirmed recurrent infections in 34 children, a recurrence rate of 12%. Multiple recurrence occurred in 14/34 (34%) children. Age of less than 6 months on entry independently predicted for recurrent UTI (odds ratio (OR): 2.9)). Compliance with prophylactic antibiotics fell throughout the year of follow up. Vesicoureteric reflux (VUR) was present in 14/34 (34%) of the group with recurrent UTI, 69/256 (27%) without recurrence. Urinary tract infection was significantly associated with bilateral and intrarenal reflux; grade 3-5 reflux independently predicted for recurrent UTI (OR: 3.5). Recurrent UTI was significantly associated with high grade DMSA defects on entry, renal parenchymal defects at 1 year follow up, and new defects at 1 year.

CONCLUSION

The independent risk factors for recurrent UTI identified by this study were an age of less than 6 months at the index UTI and grade 3-5 VUR. These findings suggest more selective targeting may minimize problems associated with prophylaxis and improve outcomes for children with urine infection.

The lung in sickle cell disease

Sickle cell disease is the most common inherited disorder in African-Americans. Although the primary defect is hematological, the changes in the erythrocytes lead to a vasculopathy with multiorgan injury. The pulmonary complications, i.e., acute chest syndrome and chronic sickle cell lung disease, are significant causes of morbidity and mortality. The pulmonary manifestations result from a unique constellation of factors which come into play in sickle cell disease. Based on the growing understanding of the molecular and cellular biology of sickle cell disease, new therapies are being developed that are likely to ameliorate the natural history of this disease and its complications.

Lessons learned from the Hunter Region Health Promoting Schools Project in New South Wales, Australia

This paper describes development, over a five-year period, of the Hunter Region Health Promoting Schools Project in New South Wales (NSW), Australia. The project implemented the principles and philosophy of the Health Promoting Schools concept and evaluated its effectiveness using a randomized controlled trial involving 22 public secondary schools. An overview of the preliminary intervention model based on the health promoting schools philosophy and trialed in a pilot study is provided. The authors also outline barriers to, and difficulties in, implementing the philosophically based intervention model in the secondary school setting. The current intervention approach, which evolved over five years, is described in relation to the roles played by project team members and school communities. In addition, the authors outline guiding principles arising from the new approach which facilitated adoption of health promotion strategies in secondary school settings.

Preclinical antitumor activity of XK469 (NSC 656889)

XK469 (NSC 656889) is a water-soluble member of the novel quinoxaline family of antitumor agents. In vitro, XK469 demonstrated selective cytotoxicity for several murine solid tumors including colorectal and mammary adenocarcinoma cell lines, when compared to both leukemia and normal epithelial cells. In vivo, XK469 was active against 7/7 murine tumors tested, including pancreatic ductal carcinomas #02 and #03, colon adenocarcinomas #38 and #51/A, mammary adenocarcinoma #16/C and the Adriamycin resistant mammary adenocarcinomas #16/C/ADR and #17/ADR. XK469 was efficacious both intravenously and orally. Regardless of dosing schedule, conventional mice tolerated higher total doses than SCID or nu/nu mice did. Despite these reduced doses, XK469 was active against xenografts of 4/6 human tumor lines including mammary adenocarcinoma MX-1, the small cell lung cancer DMS 273, the prostate model LNCaP and the CNS tumor SF295. The lower doses in the xenograft studies were below curative levels. The dose-limiting toxicity appeared to be myelosuppression with rapid host recovery (5-8 days), and in vitro assays of XK469 toxicity to murine bone marrow neutrophil progenitors CFU-GM (colony forming unit-granulocyte/macrophage) demonstrated concentration-dependent toxicity from 0.5-30 microg/mL. The difference in drug tolerance between BDF1 and SCID mice was detected in vitro as a 3-fold difference in the IC90 for CFU-GM, despite similar IC50 values. Comparative in vitro hematotoxicology studies revealed that human bone marrow CFU-GM tolerated XK469 as well as their SCID counterparts (IC90 values 5.7 vs. 7.4 microg/mL). Based on comparison with previously tested anti-cancer agents, these data suggest that humans will be able to tolerate XK469 doses that are efficacious against human tumor xenografts.