Psychosocial morbidity in women with abnormal cervical cytology managed by cytological surveillance or initial colposcopy: longitudinal analysis from the TOMBOLA randomised trial

OBJECTIVE

To compare psychosocial outcomes (follow-up related worries and satisfaction with follow-up related information and support) over 30 months of two alternative management policies for women with low-grade abnormal cervical cytology.

METHODS

Women aged 20-59 years with low-grade cytological abnormalities detected in the National Health Service Cervical Screening Programme were randomised to cytological surveillance or initial colposcopy. A total of 3399 women who completed psychosocial questionnaires at recruitment were invited to complete questionnaires at 12, 18, 24 and 30 months. Linear mixed models were used to investigate differences between arms in the two psychosocial outcomes. Each outcome had a maximum score of 100, and higher scores represented higher psychosocial morbidity.

RESULTS

On average, over 30 months, women randomised to colposcopy scored 2.5 points (95%CI -3.6 to -1.3) lower for follow-up related worries than women randomised to cytological surveillance. Women in the colposcopy arm also scored significantly lower for follow-up related satisfaction with information and support (-2.4; -3.3 to -1.4) over 30 months. For both outcomes, the average difference between arms was greatest at 12th- and 18th-month time points. These differences remained when the analysis was stratified by post-school education.

CONCLUSIONS

Women with low-grade cytology, irrespective of their management, have substantial initial psychosocial morbidity that reduces over time. Implementation of newer screening strategies, which include surveillance, such as primary HPV screening, need to consider the information and support provided to women. © 2016 The Authors. Psycho-Oncology published by John Wiley & Sons Ltd.

Reasons for participation and non-participation in a randomized controlled trial: postal questionnaire surveys of women eligible for TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears)

Background Better understanding of motivators for, and barriers to, participation in randomized controlled trials (RCTs) in different study populations and settings has the potential to improve participation of historically under-represented groups (eg, women) in future trials.

Purpose To investigate reasons why women agreed, or declined, to participate in a RCT.

Methods In two postal questionnaire-based studies, we investigated women's reasons for participation or non-participation in TOMBOLA, a RCT comparing management policies for low-grade cervical abnormalities. Four-hundred and ninety-two TOMBOLA participants (response rate 56%) completed questionnaires on reasons for participation. One-hundred and thiry-seven women (38%) who declined TOMBOLA participation completed questionnaires on reasons for this.

Results Eighty percent of women reported that one of their reasons for attending their TOMBOLA recruitment appointment was worries about their smear result. Ninety-four percent participated in the RCT because it was a worthwhile contribution to the cervical screening programme and other women; for 70% this was the most important reason. These proportions did not vary by socio-demographic factors. Thirty-two percent thought participation would result in better care. The most common reason for non-participation was preference for follow-up from the woman's GP. Logistical issues (eg, inconvenient appointments, travel time, arranging time off work or child-care) were commonly cited. Fourteen percent were too frightened to participate; this was unrelated to the grade of the recruitment smear. Limitations Response rates were not high, but there was little evidence of response bias. Structured questionnaires were used.

Conclusions Future research should address how best to deliver information to ensure different social groups appreciate potential benefits of RCT participation and provide reassurance regarding fears about participation. Simple strategies (eg, appealing to the altruism of potential participants or offering flexible recruitment clinic locations and times) might enhance RCT recruitment rates. This in turn would ensure best use of research resources thus bringing the greatest benefits to participants and the population.

Modifiable and fixed factors predicting quality of life in people with colorectal cancer

Background:

People with colorectal cancer have impaired quality of life (QoL). We investigated what factors were most highly associated with it.

Methods:

Four hundred and ninety-six people with colorectal cancer completed questionnaires about QoL, functioning, symptoms, co-morbidity, cognitions and personal and social factors. Disease, treatment and co-morbidity data were abstracted from case notes. Multiple linear regression identified modifiable and unmodifiable factors independently predictive of global quality of life (EORTC-QLQ-C30).

Results:

Of unmodifiable factors, female sex (P<0.001), more self-reported co-morbidities (P=0.006) and metastases at diagnosis (P=0.036) significantly predicted poorer QoL, but explained little of the variability in the model (R²=0.064). Adding modifiable factors, poorer role (P<0.001) and social functioning (P=0.003), fatigue (P=0.001), dyspnoea (P=0.001), anorexia (P<0.001), depression (P<0.001) and worse perceived consequences (P=0.013) improved the model fit considerably (R²=0.574). Omitting functioning subscales resulted in recent diagnosis (P=0.002), lower perceived personal control (P=0.020) and travel difficulties (P<0.001) becoming significant predictors.

Conclusion:

Most factors affecting QoL are modifiable, especially symptoms (fatigue, anorexia, dyspnoea) and depression. Beliefs about illness are also important. Unmodifiable factors, including metastatic (or unstaged) disease at diagnosis, have less impact. There appears to be potential for interventions to improve QoL in patients with colorectal cancer.

The impact of microinvasive cancer of the cervix on women during follow-up

The psychologic and psychosexual sequelae of cervical screening and disease are well recognized but most research has focused on women with cervical intraepithelial neoplasia (CIN) or women with early (stage IB) to advanced cervical cancer. There has been little work looking at women with microinvasive cancer as a unique clinical identity. Many of these women have a similar diagnostic, treatment, and follow-up pathway to those with high-grade CIN. This could result in unrecognized and ongoing health concerns. We report on a questionnaire-based case-control study, comparing the concerns of women with microinvasive cervical cancer with those of women with high-grade CIN. Women with microinvasive cancer and controls with CIN2/3 diagnosed between 2000 and 2006, from a geographically defined population, were recruited and invited to complete a postal questionnaire consisting of the Hospital Anxiety and Depression Scale (HADS) and the Process Outcome Specific Measure (POSM). Twenty-eight women diagnosed with microinvasive cancer were identified and 18 participated (response rate 64%). Fifty-eight controls were matched by age and year of treatment with 26 responding (45%). About 18% of women with microinvasive cancer had a HADS depression score of 8 or more, compared to 12% of those with CIN (P = not significant). The HADS anxiety score of 8 or more occurred in 35% of each group. There were no significant differences in terms of POSM results for sexual activity, fertility, and developing cervical cancer in the future between cases and controls. We did not find a difference between women with a previous diagnosis of microinvasive cancer and those with high-grade CIN, in terms of ongoing concerns during their follow-up. We did not identify any additional concerns for women with microinvasive cancer in the care provided in the colposcopy service.

Psychological effects of a low-grade abnormal cervical smear test result: anxiety and associated factors

Receipt of an abnormal cervical smear result often generates fear and confusion and can have a negative impact on a woman's well-being. Most previous studies have focussed on high-grade abnormal smears. This study describes the psychological and psychosocial effects, on women, of having received a low-grade abnormal smear result. Over 3500 women recruited to TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) participated in this study. Anxiety was assessed using the Hospital Anxiety and Depression Scale (HADS) at recruitment. Socio-demographic and lifestyle factors, locus of control and factors associated with the psychosocial impact of the abnormal smear result were also assessed. Women reported anxiety levels consistent with those found in previous studies of women with high-grade smear results. Women at highest risk of anxiety were younger, had children, were current smokers, or had the highest levels of physical activity. Interventions that focus particularly on women's understanding of smear results and pre-cancer, and/or directly address their fears about cancer, treatment and fertility might provide the greatest opportunity to reduce the adverse psychosocial impact of receiving a low-grade abnormal cervical smear result.

Developing a questionnaire to measure the psychosocial impact of an abnormal cervical smear result and its subsequent management: the TOMBOLA (Trial of Management of Borderline and Other Low-grade Abnormal Smears) trial

This paper describes the process of developing and testing a new questionnaire, Process Outcome Specific Measure (POSM), including an assessment of its content validity and reliability. The questionnaire was developed within the context of Trial Of Management of Borderline and Other Low-grade Abnormal smears (TOMBOLA) to assess the psychosocial impact of a low-grade abnormal cervical smear result and the subsequent management. A literature search, focus groups and thorough pre-testing involving experts and patients resulted in a short (15-item), easily completed and understood questionnaire. Questions address issues including cancer, health, fertility and sexual concerns. Repeatability was assessed in 110 TOMBOLA recruits using weighted k; all but one of the questions showed levels of reliability near to, or above, 0.5. Cronbach's standardised alpha was 0.73, indicating acceptable internal consistency. Each POSM item was correlated with the anxiety and depression sub-scales of the Hospital Anxiety Depression Scale (HADS). All except one of the questions correlated more highly with the total POSM score than with the HADS sub-scales thus indicating discriminant validity. The POSM will enable comparison of the alternative management policies for low-grade cervical smears in terms of the benefits (or otherwise) perceived by the women managed by these policies.

Human research tissue banks in the UK National Health Service: laws, ethics, controls and constraints

National Health Service (NHS) histopathology laboratories are ideally placed to bank cadaveric and surplus surgical tissue to supply the needs of research organisations, whether in the NHS, universities or the commercial sector. This review outlines the constraints to setting up a human tissue bank in an NHS histopathology laboratory, identifies the controls required and answers the question: is it ethical and legal?

Cadaveric Tissue Supply to the Commercial Sector For Research: Collaboration between NHS Pathology and NBS Tissue Services in the U.K., Extending the Options for Donors

The Peterborough Hospital Human Tissue Bank (PHHTB) and National Blood Service Tissue Services (London and South East Zone) (NBSTS) operate within the U.K. National Health Service (NHS) and have a system in place to retrieve cadaveric tissues for commercial sector research. The collaboration meets the aims of PHHTB and NBSTS and is legal, ethical and safe. This paper presents the results of the first 20 successful retrievals referred from NBSTS to PHHTB. Cadaveric retrieval of tissue for research extends the options for donors and their relatives. The research option is particularly welcomed in cases where clinical retrieval for tissue transplantation is contraindicated. We believe the system is applicable to other centres.

Personal safety and the abuse of staff in a Scottish NHS Trust

BACKGROUND

An employer's 'duty of care' is enshrined in statute and common law. This responsibility extends to identifying areas of risk to employee's safety and emotional well being.

OBJECTIVE

To identify the views of NHS staff on their safety and exposure to assault and other forms of abuse.

DESIGN

A survey by questionnaire and semi-structured interview of the staff of an NHS Trust.

SETTING

A large Scottish NHS Trust.

SUBJECTS

All 5365 staff of the Trust.

RESULTS

Two thousand two hundred and ninety four (43%) employees contributed to this survey. With regard to exposure to hazardous substances and serious infection, most staff were satisfied with safety standards and guidelines. Over a 12 month period 23% of the workforce had been assaulted, mainly by patients and 63% had experienced verbal abuse, again, mainly from patients. There were differences among occupational groups but overall 16% had been bullied; 18% had suffered discrimination; 22% had experienced harassment, and 13% had been victimized. Only 42% of individuals reported their most distressing incidents; 56% of them regarded the outcome of their reports as satisfactory.

CONCLUSIONS

Staff are generally satisfied with the steps taken to safeguard them against hazardous substances and serious infection. Assault by and abuse from patients is a considerable risk, especially for trained nurses. In terms of bullying, harassment, discrimination and victimization, the abuse of power by colleagues is also a distressing and under-reported phenomenon which needs to be addressed by regular audit and the creation of a climate in which employees feel secure enough to report such abuse and to have faith in the mechanisms set up to deal with such complaints.

Suicide by patients: questionnaire study of its effect on consultant psychiatrists

OBJECTIVE

To identify the effect of patients' suicide on consultant psychiatrists in Scotland.

DESIGN

Confidential coded postal questionnaire survey.

PARTICIPANTS

Of 315 eligible consultant psychiatrists, 247 (78%) contributed.

SETTING

Scotland.

MAIN OUTCOME MEASURES

Experience of patient suicide; the features and impact of "most distressing" suicide and what helped them to deal with it.

RESULTS

167 (68%) consultants had had a patient commit suicide under their care. Fifty four (33%) reported being affected personally in terms of low mood, poor sleep, or irritability. Changes in professional practice were described by 69 (42%) of the psychiatrists-for example, a more structured approach to the management of patients at risk and increased use of mental health legislation. Twenty four (15%) doctors considered taking early retirement because of a patient's suicide. Colleagues and family or friends were the best sources of help, and team and critical incident reviews were also useful.

CONCLUSIONS

Suicide by patients has a substantial emotional and professional effect on consultant psychiatrists. Support from colleagues is helpful, and professional reviews provide opportunities for learning and improved management of suicide and its aftermath.

Organophosphate poisoning in Perth, Western Australia, 1987-1996

This study aimed to review the presentation and management of patients with organophosphate poisoning admitted to the four tertiary teaching hospitals in Perth, Western Australia, over a 10-year period. The case notes of all 69 patients admitted with a discharge diagnosis of organophosphate poisoning were reviewed. Twenty-two of 25 patients (88%) attempting suicide were admitted to Intensive Care Units (ICUs), with a mean stay of 7 days (range 1-25 days). All but one were men, and two died. The 44 patients with accidental exposure were mainly children and had a mean stay of 2 days, with only seven going to the ICU. All survived. Complications overall included respiratory failure, convulsions, and aspiration pneumonia. Intubation and ventilation were required in 11 patients (16%), with a mean ventilation duration of 6 days (range 1-25 days). We conclude that deliberate ingestion of organophosphates is considerably more toxic than accidental exposure. Men aged 30-50 years were the most likely to attempt suicide with these agents and had prolonged ICU admissions with significant complications and mortality.

The intracellular phosphorylation of (-)-2'-deoxy-3'-thiacytidine (3TC) and the incorporation of 3TC 5'-monophosphate into DNA by HIV-1 reverse transcriptase and human DNA polymerase gamma

(-)-2'-deoxy-3'-thiacytidine (3TC) has been shown to be a potent, selective inhibitor of HIV replication in vitro, which requires phosphorylation to its 5'-triphosphate for antiviral activity. The intracellular concentration of 3TC 5'-triphosphate in phytohaemagglutinin (PHA)-stimulated peripheral blood lymphocytes (PBL) shows a linear dependence on the extracellular concentration of 3TC up to an extracellular 3TC concentration of 10 microM. At this extracellular concentration of 3TC, the resulting intracellular concentration of 3TC 5'-triphosphate is 5 microM. This value is similar to the inhibition constant (Ki) values for the competitive inhibition of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase and human DNA polymerases (10-16 microM) by 3TC 5'-triphosphate. Since the concentration of 3TC producing 90% inhibition (IC90) of HIV replication in PBLs has been reported to be 76 nM, the antiviral activity of 3TC requires intracellular concentrations of 3TC 5'-triphosphate, which would result in very little inhibition of reverse transcriptase if its sole mode of action was competitive inhibition. This apparent discrepency may be explained by the ability of 3TC 5'-triphosphate to act as a substrate for reverse transcriptase. Primer extension assays have shown that 3TC 5'-triphosphate is a substrate for HIV-1 reverse transcriptase and DNA polymerase gamma, resulting in the incorporation of 3TC 5'-monophosphate into DNA. In the case of DNA polymerase gamma, the product of this reaction (i.e. double-stranded DNA with 3TC 5'-monophosphate incorporated at the 3'-terminus of the primer strand) is also a substrate for the 3'-5' exonuclease activity of this enzyme. This may explain the low levels of mitochondrial toxicity observed with 3TC.

The kinetics of the acid-induced conformational change of influenza virus haemagglutinin can be followed using 1,1'-bis(4-anilino-5-naphthalenesulphonic acid)

1,1'-Bis(4-anilino-5-naphthalenesulphonic acid) (bis-ANS) has been shown by fluorescence spectroscopy to bind to bromelain-cleaved influenza haemagglutinin (BHA). The fluorescence intensity of 1.2 microM bis-ANS in the presence of BHA in its low-pH conformation is twenty-fold higher than in the presence of BHA in its neutral-pH conformation. The use of this probe provides a sensitive method for investigating the kinetics of the irreversible conformational change of BHA induced by low pH. At pH5.0 the reaction is described by a rapid burst followed by a double exponential increase in the fluorescence of bis-ANS, with rate constants of 5.2 +/- 0.9 x 10(-3) sec-1 and 6.7 +/- 1.9 x 10(-4) sec-1. This reaction is sensitive to the presence of tert-butylhydroquinone, an inhibitor of the conformational transition of BHA. The dependence of the reaction rate on pH indicates that the acid-induced conformational change is dependent upon the multiple protonation of the neutral-pH conformation of BHA.

Discovery and analysis of a series of C2-symmetric HIV-1 proteinase inhibitors derived from penicillin

In order to identify a suitable peptide substrate for human immunodeficiency virus-1 (HIV-1) proteinase, a range of peptides from various cleavage sites within the gag-pol polyprotein were assayed by HPLC for specific cleavage. The peptide with the optimal combination of favorable kinetics and good solubility was based on the N-terminus cleavage site of HIV-1 proteinase (KQGTVSFNF*PQIT). The HPLC assay, using the above peptide, was developed into a rapid isocratic method in order to analyze inhibition kinetics. An assay suitable for high-throughput screening was developed using a radioactively labeled peptide with the same sequence, coupled to a solid phase. Using this assay, a C2-symmetric HIV-1 proteinase inhibitor derived from penicillin was discovered during random screening of a compound library. A chemical synthesis program developed this structure into a series of potent inhibitors. The lead structures were highly selective for HIV-1 proteinase with good antiviral activity in vitro against HIV and no cytotoxicity. The HPLC assay was used to demonstrate that these compounds are competitive tight-binding inhibitors of HIV-1 proteinase.

Pharmacological evaluation of 2-amino-6(7)- and 9-amino-6-trifluoromethylbenzonorbornenes, the conformationally rigid analogues of norfenfluramine in mice

1. The possible role of conformational requirements which fenfluramine and norfenfluramine must satisfy to elicit its observed pharmacological activities was investigated in mice with the use of four conformationally-rigid norfenfluramine analogues. 2. In this study, both the syn-9-amino and endo-2-amino isomers, which structurally resemble the gauche conformation of norfenfluramine, were found to have little or no effect on spontaneous locomotor activity. 3. On the other hand, the isomers (i.e. the anti-9-amino and exo-2-amino isomers) that mimic the anti conformation of norfenfluramine were capable of causing a decrease in spontaneous motor activity similar to that of norfenfluramine. 4. The analgesic activities of these rigid analogues were also assessed and all of the isomers were found to be weakly analgesic. 5. Only the exo-2-amino isomer exhibited analgesic potency similar to that of fenfluramine. Furthermore all of these compounds were capable of enhancing the analgesic activity of morphine.

A series of penicillin derived C2-symmetric inhibitors of HIV-1 proteinase: synthesis, mode of interaction, and structure-activity relationships

The C2-symmetric diester 1 was identified by random screening as a novel inhibitor of HIV-1 proteinase. This led to the preparation of a series of related more potent amides from readily accessible penicillins. Many of the compounds showed potent antiviral activity in HIV-1-infected MT-4 cells and an ability to inhibit syncytia formation in infected C8166 cells, with no evidence of cytotoxicity. The compounds showed no activity against other aspartyl proteinases (renin, pepsin, and cathepsin D). Structure-activity relationships support a symmetrical interaction with the enzyme. Pharmacokinetic evaluation of the ethylamide 3 revealed it was subject to rapid plasma clearance and had low oral bioavailability.

Indole-2-carboxylates, novel antagonists of the N-methyl-D-aspartate (NMDA)-associated glycine recognition sites: in vivo characterization

Recent in vitro receptor binding studies have indicated that indole-2-carboxylates with halogen substitutions at the position 5 or 6 are potent competitive antagonists of the NMDA (N-methyl-D-aspartate)-associated strychnine-insensitive glycine receptor (Gray N. M., Dappen M. S., Cheng B. K., Cordi A. A., Biesterfeldt J. P., Hood W. F. and Monahan J. B. (1992) J. med. Chem. 34: 1283-1292; Hood W. F., Gray N. M., Dappen M. S., Watson G. B., Compton R. P., Cordi A. A., Larthorn T. H. and Monahan J. B. (1992) J. Pharmac. exp. Ther. 262: 654-660). In the present investigation, a series of indole-2-carboxylates and two putative antagonists of glycine receptor HA-966 (3-amino-l-hydroxypyrrolidin-2-one) and 7-chlorokynurenic acid were examined for their effects on cGMP responses, mediated by the NMDA receptor complex, in vivo. Both SC-49648 (6-chloro-2-carboxyindole-3-acetic acid, intracerebellar injection, i.c.b.) and HA-966 (i.c.b. or intraperitoneal, i.p.) antagonized increases in levels of cyclic GMP in the cerebellum of the mouse, induced by the intracerebellar administration of NMDA and D-serine, agonists of the NMDA and the NMDA-associated glycine recognition sites, respectively. The drugs SC-49648 and 7-chlorokynurenic acid (i.p.) did not affect cGMP responses, suggesting poor bioavailability in brain. Following direct intracerebellar injection, SC-49648 was eliminated with a half-life of 12 min from the brain. Following intraperitoneal administration, SC-50132, the 3-ethylester analog of SC-49648, was eliminated from the brain with a half-life of 35 min and was found to be metabolized to SC-49648, in vivo. Some lipophilic analogs of SC-49648, designed as its prodrugs, were minimally active as glycine antagonists, in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of (-)-2'-deoxy-3'-thiacytidine (3TC) 5'-triphosphate on human immunodeficiency virus reverse transcriptase and mammalian DNA polymerases alpha, beta, and gamma

(-)-2'-Deoxy-3'-thiacytidine (3TC) is a selective inhibitor of human immunodeficiency virus replication in vitro (J. A. V. Coates, N. Cammack, H. J. Jenkinson, A. J. Jowett, M. I. Jowett, B. A. Pearson, C. R. Penn, P. L. Rouse, K. C. Viner, and J. M. Cameron, Antimicrob. Agents Chemother. 36:733-739, 1992). The effect of 3TC 5'-triphosphate on both the RNA-dependent and DNA-dependent activities of human immunodeficiency virus type 1 reverse transcriptase and DNA polymerases alpha, beta, and gamma from HeLa cells was investigated. 3TC 5'-triphosphate is a competitive inhibitor (with respect to dCTP) of the RNA-dependent DNA polymerase activity (apparent Ki = 10.6 +/- 1.0 to 1.24 +/- 5.1 microM, depending on the template and primer used); the DNA-dependent DNA polymerase activity is 50% inhibited by a 3TC 5'-triphosphate concentration of 23.4 +/- 2.5 microM when dCTP is present at a concentration equal to its Km value. Chain elongation studies show that 3TC 5'-triphosphate is incorporated into newly synthesized DNA and that transcription is terminated in a manner identical to that found for ddCTP. The 50% inhibitory concentrations of 3TC 5'-triphosphate against DNA polymerases alpha, beta, and gamma at concentrations of dCTP equal to the Km were 175 +/- 31, 24.8 +/- 10.9, and 43.8 +/- 16.4 microM, respectively. More detailed kinetic studies with 3TC 5'-triphosphate and DNA polymerases beta and gamma are consistent with the fact that inhibition of these enzymes by 3TC 5'-triphosphate is competitive with respect to dCTP. The values of Ki were determined to be 18.7 microM for DNA polymerase beta and 15.8 +/- 0.8 microM for DNA polymerase gamma.

Characterization of indole-2-carboxylate derivatives as antagonists of N-methyl-D-aspartate receptor activity at the associated glycine recognition site

We have synthesized a series of indole-2-carboxylate derivatives and, with the use of radioligand binding, electrophysiological techniques and an in vivo transient bilateral carotid occlusion model of ischemic damage known to be sensitive to NMDA antagonists, have evaluated the indole-2-carboxylate derivatives ability to inhibit N-methyl-D-aspartate (NMDA) receptor activity through the associated glycine modulatory site. By using [3H]glycine to label this modulatory site, we found that the compounds with the highest affinity (Ki less than 1 microM) contained a chloro group at position C-6 and a polar, hydrogen-bond-accepting group at position C-3 of the indole ring. When these compounds were tested for their ability to modulate [3H]MK-801 [(+)-[3H]-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclophepten-5,10- imine maleate) binding, a functional assessment of NMDA receptor activation, binding was inhibited, indicative of NMDA receptor antagonist character. Schild regression analysis indicated that this antagonism was competitive with glycine. Next, several of these indole-2-carboxylate derivatives were analyzed electrophysiologically in rat cortex mRNA-injected Xenopus oocytes shown to express a functional NMDA receptor channel complex. These compounds inhibited NMDA receptor activity in a manner noncompetitive with NMDA. They also produced a parallel right-ward shift in the glycine dose response for potentiation of the NMDA responses in the oocytes and thus provided further evidence for a competitive interaction at the glycine site. Finally, in vivo transient bilateral carotid artery occlusion experiments revealed that these compounds were capable of reducing the damage typically associated with an ischemic insult in Mongolian gerbil hippocampal neurons.

BMY-14802 protects against ischemia-induced neuronal damage in the gerbil

BMY-14802, a selective sigma ligand currently under investigation as an atypical antipsychotic agent, was tested for potential anti-ischemic activity. BMY-14802 (10, 30 and 50 mg/kg) did not produce any stereotyped behavior, ataxia or seizures. When gerbils were pretreated with 10, 30 or 50 mg/kg of BMY-14802 30 min prior to bilateral occlusion of carotid arteries for 5 min, BMY-14802 significantly protected against ischemia-induced neuronal loss in the hippocampus. Thus, BMY-14802 may also be useful as an anti-ischemic agent that does not produce psychotomimetic effects.

Large scale expression and purification of recombinant HIV-1 proteinase from Escherichia coli

The availability of target proteins in sufficient quantity is a limiting factor in crystallographic studies and therefore in rational drug design. Even after optimisation, expression of recombinant proteins may be low and the only way to produce enough protein is by large scale cell growth/purification. HIV-1 proteinase in Escherichia coli, which due to its toxicity is expressed as a soluble protein only at around 0.1% of total protein, is a paradigm for this. In this paper a detailed process for large scale expression and purification of HIV-1 proteinase which delivers material of suitable quantity (30 mg from 500 g of wet weight of cells) and quality for crystallographic studies is described.

Effects of sigma ligands on mouse cerebellar cyclic guanosine monophosphate (cGMP) levels in vivo: further evidence for a functional modulation of N-methyl-D-aspartate (NMDA) receptor complex-mediated events by sigma ligands

In the present investigation, the effects of sigma ligands [WY-47384 [8-fluoro-2,3,4,5-tetrahydro-2[3-(3-pyridinyl)propyl)1H- pyrido(4,3b)indole], (+)-pentazocine, (+)-SFK 10,047 (N-allylnormetazocine), mafoprazine, opipramol, dextromethorphan, dextrorphan, (+)-3-PPP [3-(3-hydroxyphenyl)-N-propylpiperidine], (-)-butaclamol, DTG [1,3-di(2-tolyl)guanidine], rimcazole, ifenprodil and BMY-14802 [alpha-(fluorophenyl)-4-(5-fluoropyrimidinyl)-1-piperazine butanol]] on harmaline-, pentylenetetrazol (PTZ)-, methamphetamine (MA)- and D-serine-induced increases in mouse cerebellar levels of cGMP were determined. Ifenprodil, BMY-14802, dextromethorphan, dextrorphan, (+)-SKF 10,047, opipramol and mafoprazine reversed harmaline-, PTZ-, MA- and D-serine-induced increases in levels of cGMP. Rimcazole reversed only the harmaline-induced response. WY-47384 reversed harmaline-, MA-, D-serine-, but not PTZ- or quisqualate-induced increases in levels of cGMP. (+)-Pentazocine attenuated harmaline- and D-serine-, but not PTZ- and MA-induced cGMP responses. Haloperidol did not affect harmaline- and D-serine-induced cGMP responses. (+)-3-PPP and (-)-butaclamol did not affect any of the responses studied. Furthermore, (+)-3-PPP-induced increases in levels of cGMP were reversed by the competitive N-methyl-D-aspartate (NMDA) antagonist, CPP]3-(2-carboxypiperazin-4-yl)propyl- 1-phosphonic acid, the non-competitive NMDA antagonist, (+)-MK-801 (dizocilipine maleate), the NMDA-associated glycine receptor antagonist, HA-966 (3-amino-1-hydroxypyrrolidin-2-one), the partial glycine agonist, DCS (D-cycloserine) as well as by the sigma ligands, ifenprodil, WY-47384, (+)-pentazocine, (+)-SKF 10,047, dextromethorphan and dextrorphan but not by rimcazole.(ABSTRACT TRUNCATED AT 250 WORDS)

(+) 3-[3-hydroxyphenyl-N-(1-propyl) piperidine] selectively differentiates effects of sigma ligands on neurochemical pathways modulated by sigma receptors: evidence for subtypes, in vivo

The effects of sigma ligands, (+)3PPP 3-[3-hydroxyphenyl-N(1-propyl) piperidine] and (-)butaclamol, were evaluated in vivo on the metabolism of dopamine (DA) and in the striatum release of adrenocorticotrophic hormone (ACTH) and prolactin in the rat and changes in levels of cyclic guanosine monophosphate (cGMP) in the cerebellum of the mouse and compared with the effects of (+)NANM (N-allyl-normetazocine, SKF 10,047) and (+)pentazocine. Both (+)3PPP and (-) butaclamol decreased the release of prolactin and did not affect the metabolism of DA. N-Allyl-normetazocine and (+)pentazocine increased release of prolactin and have been shown previously to increase the metabolism of DA. All four ligands increased release of ACTH; however, only the increases caused by (+)NANM and (+)pentazocine were reversed by pretreatment with CPP, a N-methyl-D-aspartate (NMDA) receptor antagonist. (+)Pentazocine and (+)NANM inhibited the NMDA receptor-mediated changes in levels of cGMP in the cerebellum of the mouse, while (+)3PPP and (-)butaclamol did not attenuate the response to NMDA. In addition to further confirming a functional interaction between sigma receptors and NMDA receptors, these studies divide the observed effects of putative sigma ligands into two groups, characterized by benzomorphan compounds and non-benzomorphan compounds, suggesting the possibility of subtypes at sigma receptor in vivo.

Evaluation of U-50,488H analogs for neuroprotective activity in the gerbil

U-50,488H, a kappa (kappa) opioid ligand with moderate potency at sigma (sigma) receptors, protects against mechanical and ischemia-induced injury. The purpose of this study was to evaluate the possibility that sigma-receptors may be involved in mediating the neuroprotective actions of U-50,488H. This possibility was examined by testing the potential of a series of U-50,488H analogs, which are potent sigma-ligands with minimal activity at kappa-opioid receptors, to protect against ischemia-induced neuronal damage in the gerbil. Like U-50,488H, BD-449 (20 mg/kg), the cis-diastereomer of U-50,4888H, protected against ischemia-induced neuronal damage as did BD-737 (50 and 30 mg/kg) and BD-738 (50 mg/kg). All 3 compounds interacted selectively with sigma-receptors. In contrast, BD-601 (50 mg/kg), did not protect against ischemia-induced neuronal damage, although it also interacted potently with sigma-receptors. One difference between the compounds that were neuroprotective and BD-601 is that only BD-601 produced sigma-like behavioral effects in the rat. Thus, it is possible that BD-601 may interact differently or at a different sigma-subtype than BD-449, BD-737 and BD-738 with sigma-receptors. However, these results clearly indicate that an interaction with kappa-opioid receptors is not required for anti-ischemic activity, and that sigma-receptors may play a role in neuroprotection.

Novel indole-2-carboxylates as ligands for the strychnine-insensitive N-methyl-D-aspartate-linked glycine receptor

A series of indole-2-carboxylates were prepared and evaluated for their ability to inhibit the binding at the strychnine-insensitive glycine receptor that is associated with the NMDA-PCP-glycine receptor complex. All of the compounds were selective for the glycine site relative to other sites on the receptor macrocomplex and several of the compounds in this series were found to have submicromolar affinity for this receptor. The lead compound, 2-carboxy-6-chloro-3-indoleacetic acid (Ki = 1.6 microM vs [3H]glycine), was also found to noncompetitively inhibit the binding of MK-801, a ligand for the phencyclidine site on the receptor macrocomplex. These latter data suggest that the compound functions as an antagonist at the strychnine-insensitive glycine receptor. The structural activity relationships within this series of indole-2-carboxylates is discussed and several key pharmacophores are identified for this series of glycine ligands. In general, the most potent compounds were the C-3 acetamides, with N-propyl-2-carboxy-6-chloro-3-indoleacetamide having the highest receptor affinity.

Expression of an autoprocessing CAT-HIV-1 proteinase fusion protein: purification to homogeneity of the release 99 residue proteinase

The 99 residue human immunodeficiency virus type 1 proteinase has been expressed in Escherichia coli as part of an autocleaving fusion protein. Expression of the fusion protein is toxic to the host cells, however yields of the released proteinase have been improved by optimising induction nad harvest times to increase culture biomass, and decrease degradation of the proteinase. Soluble proteinase was extracted from these cells by a simple and highly efficient three step process. N-terminal sequence analysis confirms that the enzyme preparation is highly pure and correctly autoprocessed. The proteinase cleaves peptide substrate IGCTLNFPISPIETV between F and P at pH 6.0 with a Km of 310 microM and a Kcat of 14s-1. The enzyme is sensitive to its ionic environment, showing stimulation of activity at high salt concentrations, and shows a pH optimising 5.5.

Synthesis and evaluation of N-substituted cis-N-methyl-2-(1-pyrrolidinyl)cyclohexylamines as high affinity sigma receptor ligands. Identification of a new class of highly potent and selective sigma receptor probes

Certain benzeneacetamides [(-)- and (+)-cis-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl) cyclohexyl]benzeneacetamide] were recently reported to be potent sigma receptor ligands. In order to determine whether efficacy for the sigma receptor could be improved, a series of compounds related to the benzeneacetamides, N-substituted cis-2-(1-pyrrolidinyl)-N-methylcyclohexylamines, were synthesized and their structure-activity requirements were determined. The compounds were synthesized by starting with the previously reported (+/-)-, 1S,2R-(+)-, and 1R,2S-(-)-cis-2-(1-pyrrolidinyl)-N-methylcyclohexylamines. Analysis of sigma ([3H](+)-3-PPP), kappa ([3H]bremazocine and [3H]U69,593), dopamine-d2 ([3H](-)-sulpiride), and phencyclidine (PCP) ([3H]TCP) receptor binding in guinea pig brain revealed a number of highly potent and selective sigma receptor ligands. Notably, 1S,2R-cis-(-)-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-(2-naphthyl) acetamide [(-)-29] (Ki = 8.66 +/- 0.35 nM), (+/-)-cis-2-amino-4,5-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclohexyl] benzeneacetamide [(+/-)-17] (Ki = 11 +/- 3 nM), 1S,2R-(-)-cis-N-methyl-N-[2-(3,4-dichlorophenyl)ethyl]-2-(1-pyrrolidinyl ) cyclohexylamine [(-)-44] (Ki = 1.3 +/- 0.3 nM), and 1R,2S-(+)-cis-N-methyl-N-[2-(3,4-dichlorophenyl)ethyl]-2-(1-pyrrolidinyl ) cyclohexylamine. [(+)-44] (Ki = 6 +/- 3 nM) exhibited very high affinity at sigma receptors, by displacement of [3H]-(+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine [( 3H]-(+)-3-PPP). These compounds showed insignificant affinity for kappa, dopamine, or PCP receptors, making them valuable tools for the study of sigma receptors. Furthermore, these compounds also exhibited enantioselectivity ranging from 5-fold for (+)- and (-)-44 to 160-fold for (+)- and (-)-29. Several other compounds showed equivalent selectivity but displayed lower sigma receptor affinity.

Ifenprodil and SL 82.0715 potently inhibit binding of [3H](+)-3-PPP to sigma binding sites in rat brain

SL 82.0715 and ifenprodil are potent anti-ischemic agents, which are believed to be due to non-competitive antagonism of N-methyl-D-aspartate (NMDA). It has been proposed that SL 82.0715 and ifenprodil non-competitively antagonize the actions of NMDA by interacting as antagonists with a polyamine site associated with the NMDA/phencyclidine (PCP)/glycine complex. The present study demonstrates that the actions of SL 82.0715 and ifenprodil may also be due in part to an interaction with sigma binding sites, a property that is not shared with polyamines.

H1 antihistamines interact with central sigma receptors

Several antihistamines were evaluated for their ability to interact with sigma, muscarinic and histaminic H1 binding sites in rat brain preparations. All of the antihistamines were able to interact with the sigma site, as well as the other two sites. In addition, tripelennamine was found to elicit sigma-like behaviors when administered to rats. This affinity for the sigma site suggests that the compounds may elicit some of their undesirable CNS side effects via this interaction.

Phencyclidine-like effects of tetrahydroisoquinolines and related compounds

A series of 1,2,3,4-tetrahydroisoquinolines, tetrahydrothieno[2,3-c]pyridines, and related compounds were evaluated for their ability to inhibit binding of [3H]-1-[1-(2-thienyl)piperidine and [3H]-N-allylnormetazocine to phencyclidine (PCP) and sigma receptors, respectively. A representative series of compounds was evaluated in behavioral assays to determine the ability of the compounds to induce PCP-like stereotyped behavior and ataxia. All of the compounds caused stereotyped behavior and ataxia, indicating their agonist actions at the PCP site.

Phencyclidine. Physiological actions, interactions with excitatory amino acids and endogenous ligands

Phenycyclidine (PCP) produces many profound effects in the central nervous system. PCP has numerous behavioral and neurochemical effects such as inhibiting the uptake and facilitating the release of dopamine, serotonin, and norepinephrine. PCP also interacts with sigma, mu opioid, muscarinic, and nicotinic receptors. However, the psychotomimetic effects induced by PCP are believed to be mediated by specific PCP receptors, where PCP binds with greater potency than sigma compounds. Electrophysiological, behavioral, and neuro-chemical evidence strongly suggests that at least some of the many PCP actions result from antagonism of excitatory amino acid-induced responses via PCP receptors. The recent isolation and partial characterization of the alpha and beta endopsychosins and the identification of other endogenous ligands for the PCP and sigma receptors, is another promising area of research in the elucidation of the physiological role of an endogenous PCP and sigma system.

The effects of stereoisomers of 2-amino-6(7)- and 9-amino-6-trifluoromethylbenzonorbornenes on food intake, brain serotonin concentration, and monoamine oxidase activity

To evaluate the importance of the conformation of fenfluramine in eliciting its various central nervous system effects, the isomers of 2-amino-6(7)- and 9-amino-6-trifluoromethylbenzonorbornene were employed as conformationally defined analogs of norfenfluramine. In this series of isomeric amines, the exo-2 and anti-9 isomers resemble the fully extended conformation of fenfluramine, whereas the endo-2 and syn-9 isomers resemble the folded conformation. The exo-2 and anti-9 isomers were equi-effective in reducing food intake in the rat, but were approximately seven times less potent than fenfluramine. The endo-2 and syn-9 isomers had no effect on food intake up to a dose of 40 mg/kg. All of the isomers were as effective as amphetamine in inhibiting brain monamine oxidase type B. These isomers also inhibited monoamine oxidase type A to the same extent as type B, but were significantly less potent than amphetamine in inhibiting this form of the enzyme. The effects at anorectic doses on brain serotonin (5-HT) concentration were also studied. Although fenfluramine decreased brain 5-HT concentration, the exo-2, syn-9 and anti-9 isomers had no significant effect. The endo-2 isomers caused an 11% decrease in 5-HT concentration, but this effect was observed at higher doses of the compound. The data suggest that the fully extended conformation of fenfluramine is preferred over the folded conformation for eliciting its anorectic activity. However, no conclusion can be made for the conformational requirements for the other biological responses investigated in this study.

The effects of stereoisomers of 2- and 9- aminobenzonorbornenes on food intake, brain serotonin concentration and monoamine oxidase activity in the rat

To evaluate the importance of the conformation of amphetamine in eliciting its various central nervous system effects, the conformationally defined analogs of amphetamine. In this series of isomeric amines, the exo-2 and anti-9 isomers resemble the fully extended conformation of amphetamine, whereas the endo-2 and syn-9 isomers resemble the folded conformation. The exo-2 and anti-9 isomers were equally as effective in reducing food intake in the rat, but were much less potent than amphetamine. The endo-2 and syn-9 isomers had no effect on food intake up to a dose of 40 mg/kg. These latter two isomers also caused very little inhibition of monoamine oxidase in vitro. The exo-2 and anti-9 isomers, however, were nearly as effective as amphetamine in inhibiting monoamine oxidase type A, but only amphetamine and the anti-9 isomer inhibited monoamine oxidase type B. The effects at anorectic doses on brain serotonin (5-HT) concentration were also studied. Although amphetamine had no effect on the 5-HT concentration and fenfluramine decreased its concentration, the exo-2 and anti-9 isomers caused a significant increase in brain 5-HT. The anti-9 isomer caused a 14% increase in 5-HT, whereas the exo-2 isomer gave a 49% increase over controls. The data suggest that the fully extended conformation of amphetamine is preferred over the folded conformation for eliciting its biological responses, although the rigid analogs were less potent than amphetamine.