'Shame on you'--the psychosocial impact of genital warts

We aimed to investigate whether patients with genital warts experience greater feelings of shame and lower self-esteem compared with controls. Sixty patients with genital warts were compared with 60 asymptomatic genitourinary (GU) medicine patients and 60 orthopaedic outpatients. The shame scores of those with warts (31.08) were significantly higher (P < 0.0001) than either control group (GU medicine controls 20.77; orthopaedic controls 19.00). The impact on health-related quality of life (HRQoL) by each of the individual emotional parameters of shame, low self-esteem, intrusive thoughts, avoidance behaviour and self-efficacy impact was examined in the wart sample group. Only internalized shame (P = 0.001) and intrusive thoughts (P < 0.0001) were significant in predicting HRQoL scores. There are emotional implications in having genital warts, which can have a profound effect on a patient's quality of life and these need addressing just as much as the physical warts.

Synthesis and total 1H- and 13C-NMR assignment of cephem derivatives for use in ADEPT approaches

We report the synthesis and total NMR characterization of 5-thia-1-azabicyclo-[4.2.0]oct-2-ene-2-carboxylic acid-3-[[[(4’’-nitrophenoxy)carbonyl]oxy]-methyl]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (5), a new cephalosporin derivative. This compound can be used as the carrier of a wide range of drugs containing an amino group. The preparation of the intermediate product, 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]-diphenylmethyl ester-5-dioxide (6), as well as the synthesis of the antimalarial primaquine prodrug 5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid-3-[methyl 4-(6-methoxyquinolin-8-ylamino)pentylcarbamate]-8-oxo-7-[(2-thienyloxoacetyl)amino]- 5-dioxide (7) are also described, together with their total ¹H- and ¹³C-NMR assignments.

Posttraumatic stress and co-morbidity following myocardial infarction among older patients: the role of coping

This study aimed to investigate co-morbidity and coping strategies among older patients who suffer from different levels of posttraumatic stress disorder (PTSD) following myocardial infarction. Ninety-six older myocardial infarction (MI) patients were recruited from two general practices and completed the Posttraumatic Stress Diagnostic Scale (PDS), the General Health Questionnaire-28 (GHQ-28) and the COPE Scale. Ninety-two older patients with no previous MI experience constituted the control. Using the PDS, 30, 42 and 28% had full, partial and no-PTSD respectively. There were significant differences between the patient groups and the control on all GHQ-28 sub-scales. Significant differences were also identified between the patient groups in the following coping strategies: seeking emotional social support, suppression of competing activities, restraint coping, focusing on and venting of emotion, mental and behavioural disengagement. Controlling for bypass surgery, previous mental health difficulties, angioplasty, heart failure and angina, MANCOVA results did not change the overall results of the GHQ-28 but changed the results of coping in that seeking emotional social support and behavioural disengagement stopped being significant. Coping was a partial mediator between different levels of post-MI PTSD and co-morbidity. Depending on the severity of PTSD symptoms, co-morbidity and coping strategies can vary among older patients. Older patients with full-PTSD tend to use both maladaptive coping strategies as well as problem-focused coping.

Rapid test for the evaluation of the activity of the prodrug hydroxymethylnitrofurazone in the processing of Trypanosoma cruzi messenger RNAs

No fully effective treatment has been developed since the discovery of Chagas' disease by Carlos Chagas in 1909. Since drug-resistant Trypanosoma cruzi strains are occurring and the current therapy is effectiveness in the acute phase but with various adverse side effects, more studies are needed to characterize the susceptibility of T. cruzi to new drugs. Many natural and/or synthetic substances showing trypanocidal activity have been used, even though they are not likely to be turned into clinically approved drugs. Originally, drug screening was performed using natural products, with only limited knowledge of the molecular mechanism involved in the development of diseases. Trans-splicing, which is unusual RNA processing reaction and occurs in nematodes and trypanosomes, implies the processing of polycistronic transcription units into individual mRNAs; a short transcript spliced leader (SL RNA) is trans-spliced to the acceptor pre-mRNA, giving origin to the mature mRNA. In the present study, permeable cells of T. cruzi epimastigote forms (Y, BOL and NCS strains) were treated to evaluate the interference of two drugs (hydroxymethylnitrofurazone - NFOH-121 and nitrofurazone) in the trans-splicing reaction using silver-stained PAGE analysis. Both drugs induced a significant reduction in RNA processing at concentrations from 5 to 12.5 microM. These data agreed with the biological findings, since the number of parasites decreased, especially with NFOH-121. This proposed methodology allows a rapid and cost-effective screening strategy for detecting drug interference in the trans-splicing mechanism of T. cruzi.

Psychosocial benefits of solitary reminiscence writing: an exploratory study

Claims have been made that reminiscence has benefits for older people's psychological well-being, and that writing memories may be a therapeutic process. This paper describes an exploratory study in which five nursing home residents engaged in a process of writing their memories by themselves, in a series of booklets containing memory prompts and photographs, over a period of four weeks. Each completed booklet was typed up by researchers and returned to participants the following week, with a bound copy provided to participants at the end of the study period. Analysis focuses on two sets of data: an in-depth case study of one participant, and a thematic analysis of field notes, researcher reflections, and the written material produced by the other study participants. The case study revealed three main themes: views on the past; sharing the past; and confidence in writing about the past. The field note analysis indicated the presence of four themes: proof and maintenance of skills; psychological or internal processes; social contact; and pleasure in reminiscence. The writing was seen as cathartic and provided a meaningful purpose, an opportunity to exercise writing skills and memory, and a focus for participants to share key stories with others. This exploratory study suggests that there is potential in using solitary writing within a reminiscence framework to improve psychological well-being in older people. However, caution should be exercised when encouraging older people to write their stories. Issues of confidentiality, audience, support, and appropriateness of the activity for the individual need consideration.

Synthesis and in vitro evaluation of potential antichagasic hydroxymethylnitrofurazone (NFOH-121): a new nitrofurazone prodrug

The synthesis of mutual prodrugs of nitrofurazone with primaquine, using specific and nonspecific spacer groups, has been previously attempted seeking selective antichagasic agents. The intermediate reaction product, hydroxymethylnitrofurazone (NFOH-121), was isolated and tested in LLC-MK(2) culture cells infected with trypomastigotes forms of Trypanosoma cruzi showing higher trypanocidal activity than nitrofurazone and benznidazol in all stages. The mutagenicity tests showed that the prodrug was less toxic than the parent drug. Degradation assays were carried out in pH 1.2 and 7.4.

Hepatocellular carcinoma: from bedside to proteomics

Hepatocellular carcinoma (HCC or hepatoma) is the most common primary cancer of the liver. It is responsible for approximately one million deaths each year, mainly in underdeveloped and developing countries. The aetiological factors identified in the development of HCC included persistent infection by hepatitis B and hepatitis C viruses, and exposure to aflatoxins. Although immunization can protect individuals from being infected by the hepatitis B virus, the early detection of HCC in those who have been infected by the virus remains a challenge. Thus most HCCs present late and are not suitable for curative treatment. Hence there is a tremendous interest and urgency to identify novel HCC diagnostic marker(s) for early detection, and tumour specific disease associated proteins as potential therapeutic targets in the treatment of HCC. Screening for these HCC proteins has been facilitated by proteomics, a key technology in the global analysis of protein expression and understanding gene function. Present and earlier proteome analyses of HCC have used predominantly experimental in vitro systems. The protein expression profiles of several hepatoma cell lines such as HepG2, Huh7, SK-Hep1, and Hep3B have been compared with normal liver, and nontransformed cell lines (Chang and WRL-68), while a comprehensive proteome analysis to create a protein database was carried out for the cell line HCC-M. In the future, proteome analyses utilizing tumour tissues, which reflect the pathological state of HCC more closely, will be undertaken. This work will complement the gene expression studies of HCC which are already underway. Efforts have also been directed at the proteome analysis of hepatic stellate cells, as these cells play an important role in liver fibrosis. Since liver fibrosis is reversible but not cirrhosis, it is of considerable importance to identify therapeutic targets that can slow its progression.

Hepatocellular carcinoma: from bedside to proteomics

Hepatocellular carcinoma (HCC or hepatoma) is the most common primary cancer of the liver. It is responsible for approximately one million deaths each year, mainly in underdeveloped and developing countries. The aetiological factors identified in the development of HCC included persistent infection by hepatitis B and hepatitis C viruses, and exposure to aflatoxins. Although immunization can protect individuals from being infected by the hepatitis B virus, the early detection of HCC in those who have been infected by the virus remains a challenge. Thus most HCCs present late and are not suitable for curative treatment. Hence there is a tremendous interest and urgency to identify novel HCC diagnostic marker(s) for early detection, and tumour specific disease associated proteins as potential therapeutic targets in the treatment of HCC. Screening for these HCC proteins has been facilitated by proteomics, a key technology in the global analysis of protein expression and understanding gene function. Present and earlier proteome analyses of HCC have used predominantly experimental in vitro systems. The protein expression profiles of several hepatoma cell lines such as HepG2, Huh7, SK-Hep1, and Hep3B have been compared with normal liver, and nontransformed cell lines (Chang and WRL-68), while a comprehensive proteome analysis to create a protein database was carried out for the cell line HCC-M. In the future, proteome analyses utilizing tumour tissues, which reflect the pathological state of HCC more closely, will be undertaken. This work will complement the gene expression studies of HCC which are already underway. Efforts have also been directed at the proteome analysis of hepatic stellate cells, as these cells play an important role in liver fibrosis. Since liver fibrosis is reversible but not cirrhosis, it is of considerable importance to identify therapeutic targets that can slow its progression.

Hepatocellular carcinoma: from bedside to proteomics

Hepatocellular carcinoma (HCC or hepatoma) is the most common primary cancer of the liver. It is responsible for approximately one million deaths each year, mainly in underdeveloped and developing countries. The aetiological factors identified in the development of HCC included persistent infection by hepatitis B and hepatitis C viruses, and exposure to aflatoxins. Although immunization can protect individuals from being infected by the hepatitis B virus, the early detection of HCC in those who have been infected by the virus remains a challenge. Thus most HCCs present late and are not suitable for curative treatment. Hence there is a tremendous interest and urgency to identify novel HCC diagnostic marker(s) for early detection, and tumour specific disease associated proteins as potential therapeutic targets in the treatment of HCC. Screening for these HCC proteins has been facilitated by proteomics, a key technology in the global analysis of protein expression and understanding gene function. Present and earlier proteome analyses of HCC have used predominantly experimental in vitro systems. The protein expression profiles of several hepatoma cell lines such as HepG2, Huh7, SK-Hep1, and Hep3B have been compared with normal liver, and nontransformed cell lines (Chang and WRL-68), while a comprehensive proteome analysis to create a protein database was carried out for the cell line HCC-M. In the future, proteome analyses utilizing tumour tissues, which reflect the pathological state of HCC more closely, will be undertaken. This work will complement the gene expression studies of HCC which are already underway. Efforts have also been directed at the proteome analysis of hepatic stellate cells, as these cells play an important role in liver fibrosis. Since liver fibrosis is reversible but not cirrhosis, it is of considerable importance to identify therapeutic targets that can slow its progression.

Cloning and characterization of a DEAD box RNA helicase from the viable seedlings of aged mung bean

Seeds stored under adverse conditions will reduce the viability of germination as a result of induced aging. We have established a procedure to induce accelerated aging for studying the process of aging in mung bean (Vigna radiata) seeds at the molecular level. A full-length cDNA was isolated from acceleratedly aged mung bean seedlings. The cDNA, VrRH1 (Vigna radiata RNA helicase 1), contains an open reading frame of 2139 bp encoding a protein of 713 amino acids. VrRHI has seven highly conserved motifs including the DEAD box as in the case of other plant RNA helicases. VrRHI was sub-cloned into an expression vector pET-28b (+), over-expressed in Escherichia coli BL 21 and purified by a Ni2+-agarose column. The expressed protein showed double-stranded RNA unwinding and ATPase activities. Either ATP or dATP is required for the unwinding activity, indicating that VrRHI is an ATP/dATP-dependent RNA helicase. Northern blot analysis showed the presence of mRNAs hybridized with a full-length cDNA fragment of VrRHI (VrRH transcripts) in mung bean seeds that were imbibed for 16 to 32 h after accelerated aging treatment. The amount of these mRNAs reached a maximum in 24 h imbibed seeds after the treatment. The accumulation of VrRH transcripts was shown to lead to the appearance of 25S and 18S rRNAs in the imbibed aging mung bean seeds. The results suggest that VrRHI may play a role in the viability of mung bean seeds.

A novel dimer of a C-type lectin-like heterodimer from the venom of Calloselasma rhodostoma (Malayan pit viper)

We have isolated a potent platelet aggregation inducer from the crude venom of Calloselasma rhodostoma (Malayan pit viper), termed rhodoaggretin, with a novel oligomeric structure consisting of a dimer of C-type lectin-like heterodimers. On the basis of its native molecular mass of 66 kDa, and a M(r) of 30 kDa for its disulfide-linked alphabeta-heterodimer, we propose that rhodoaggretin exists as a (alphabeta)2 complex in the native state. We postulate that the di-dimer is stabilized by non-covalent interactions as well as by an intersubunit disulfide bridge between the two alphabeta-heterodimers. This conclusion is based on the following observations: (a) sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the non-reduced rhodoaggretin gave a major 28 and a minor 52 kDa band. (b) Prior treatment of rhodoaggretin with a limited amount of 2-mercaptoethanol (2-ME; 0.1%) resulted in the complete abolishment of the 52 kDa band in SDS-PAGE. (c) Two-dimensional SDS-PAGE in the presence of 3% 2-ME showed that both the 28 and 52 kDa bands gave two bands each with M(r)s of 18 (alpha-subunit) and 15 (beta-subunit) kDa. (d) Mass spectrometric analyses showed that purified rhodoaggretin had a M(r) of 30155.39+/-3.25 Da while its s-pyridylethylated alpha- and beta-subunits had M(r)s of 16535.62+/-2.98 and 15209.89+/-1.61 Da respectively. These molecular weight data suggested the presence of 15 cysteinyl residues in rhodoaggretin as compared to the 14 that are reported for the heterodimeric C-type lectin-like proteins. This extra cysteinyl residue is a candidate for the formation of the intersubunit disulfide bond in the (alphabeta)2 complex. (e) Homology structural modeling studies showed that the extra cysteinyl residue can indeed form a disulfide bond that covalently links the two alphabeta-heterodimers as proposed above.

Proteomic investigation of metabolic shift in mammalian cell culture

Mammalian cells, under typical cultivation conditions, produce large quantities of lactate and ammonia that affect cell growth adversely and result in low cell concentration. Controlled nutrient feeding to maintain low concentrations of glucose and glutamine reduces metabolite production drastically, altering the metabolism of the cells. This metabolic shift results in higher cell concentration in continuous cultures and does not affect the specific productivity of the cells. We have taken a proteomics approach to investigate the differential protein expression with metabolic shift. Using two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS), we have found at least eight differentially expressed spots; two proteins were down-regulated, and the others were up-regulated with metabolic shift. These included metabolic enzymes, the brain form of phosphoglycerate mutase, which was down-regulated, and the precursor of the 23 kDa subunit of NADH-ubiquinone oxidoreductase, which was up-regulated. Another enzyme, the L1 isozyme of ubiquitin carboxyl-terminal hydrolase, which is involved in protein turnover and degradation, was also up-regulated in the metabolically altered cells. The remaining down-regulated spot had been identified as two isoforms of cytoplasmic actins, while three of the up-regulated spots were viral GAG polyproteins from various murine viruses. An unidentified protein was also up-regulated in the cells with altered metabolic state. This study shows the potential of using a proteomics approach in deciphering the intracellular changes in cells with physiological changes such as metabolism shift. The new insight into cell metabolism afforded by this analysis will greatly facilitate process optimization of continuous cell cultures.

Hepatocellular carcinoma: from bedside to proteomics

Hepatocellular carcinoma (HCC or hepatoma) is the most common primary cancer of the liver. It is responsible for approximately one million deaths each year, mainly in underdeveloped and developing countries. The aetiological factors identified in the development of HCC included persistent infection by hepatitis B and hepatitis C viruses, and exposure to aflatoxins. Although immunization can protect individuals from being infected by the hepatitis B virus, the early detection of HCC in those who have been infected by the virus remains a challenge. Thus most HCCs present late and are not suitable for curative treatment. Hence there is a tremendous interest and urgency to identify novel HCC diagnostic marker(s) for early detection, and tumour specific disease associated proteins as potential therapeutic targets in the treatment of HCC. Screening for these HCC proteins has been facilitated by proteomics, a key technology in the global analysis of protein expression and understanding gene function. Present and earlier proteome analyses of HCC have used predominantly experimental in vitro systems. The protein expression profiles of several hepatoma cell lines such as HepG2, Huh7, SK-Hep1, and Hep3B have been compared with normal liver, and nontransformed cell lines (Chang and WRL-68), while a comprehensive proteome analysis to create a protein database was carried out for the cell line HCC-M. In the future, proteome analyses utilizing tumour tissues, which reflect the pathological state of HCC more closely, will be undertaken. This work will complement the gene expression studies of HCC which are already underway. Efforts have also been directed at the proteome analysis of hepatic stellate cells, as these cells play an important role in liver fibrosis. Since liver fibrosis is reversible but not cirrhosis, it is of considerable importance to identify therapeutic targets that can slow its progression.

Environmental and developmental regulation of the wound-induced cell wall protein WI12 in the halophyte ice plant

A wounded gene WI12 was used as a marker to examine the interaction between biotic stress (wounding) and abiotic stress (high salt) in the facultative halophyte ice plant (Mesembryanthemum crystallinum). The deduced WI12 amino acid sequence has 68% similarity to WUN1, a known potato (Solanum tuberosum) wound-induced protein. Wounding, methyl jasmonate, and pathogen infection induced local WI12 expression. Upon wounding, the expression of WI12 reached a maximum level after 3 h in 4-week-old juvenile leaves, whereas the maximum expression was after 24 h in 8-week-old adult leaves. The temporal expression of WI12 in salt-stressed juvenile leaves was similar to that of adult leaves. The result suggests that a salt-induced switch from C3 to Crassulacean acid metabolism has a great influence on the ice plant's response to wounding. The expression of WI12 and the accumulation of WI12 protein were constitutively found in phloem and in wounded mesophyll cells. At the reproductive stage, WI12 was constitutively found in petals and styles, and developmentally regulated in the placenta and developing seeds. The histochemical analysis showed that the appearance of WI12 is controlled by both environmental and developmental factors. Immunogold labeling showed WI12 preferentially accumulates in the cell wall, suggesting its role in the reinforcement of cell wall composition after wounding and during plant development.

Identification of a serine protease inhibitor homologue in Bird's Nest by an integrated proteomics approach

For centuries, the edible nests of Collocalia spp. ("Bird's Nests") have been used as a Chinese delicacy that had been claimed to be an effective health-giving tonic. However, clinical studies indicated that in Singapore, Bird's Nest is the most common cause of food-induced anaphylaxis in children, which could lead to potentially life-threatening allergenic reactions. The purpose of this study was to characterize the major allergens in Bird's Nest by using the combined technologies of two-dimensional gel electrophoresis (2-DE), immunochemistry, N-terminal protein sequencing, and mass spectrometry. Results from the immunostaining of the Western blots of the Bird's Nest 2-DE separated proteins with the sera from allergic patients indicated the presence of a major allergen of 66 kDa. Initial searches of the matrix assisted laser desorption/ionization--time of flight--mass spectrometry (MALDI-TOF-MS) tryptic peptide masses of the allergen in the SWISS-PROT and NCBI nonredundant databases revealed that this protein was novel. Based on the partial protein sequence information obtained from N-terminal microsequencing and nanoelectrospray-tandem MS, the 66 kDa immunoreactive allergen was found to be homologous to ovoinhibitor, a Kazal-type serine protease inhibitor, which is one of the dominant allergens found in chicken egg white.

Proteome analysis of a human heptocellular carcinoma cell line, HCC-M: an update

Recently, we reported the proteome analysis of a human hepatocellular carcinoma cell line, HCC-M (Electrophoresis 2000, 21, 1787-1813), using two-dimensional gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). From a total of 408 unique spots excised from the 2-DE gel, 301 spots yielded good MALDI spectra. Out of these, 272 spots had matches returned from the database search leading to the identification of these proteins. Here, we report the results on the identification of the remaining 29 spots using nanoelectrospray ionization-tandem mass spectrometry (nESI-MS/MS). First, "peptide tag sequencing" was performed to obtain partial amino acid sequences of the peptides to search the SWISS-PROTand NCBI nonredundant protein databases. Spots that were still not able to find any matches from the databases were subjected to de novo peptide sequencing. The tryptic peptide sequences were used to search for homologues in the protein and nucleotide databases with the NCBI Basic Local Alignment Search Tool (BLAST), which was essential for the characterization of novel or post-translationally modified proteins. Using this approach, all the 29 spots were unambiguously identified. Among them, phosphotyrosyl phosphatase activator (PTPA), RNA-binding protein regulatory subunit, replication protein A 32 kDa subunit (RP-A) and N-acetylneuraminic acid phosphate synthase were reported to be cancer-related proteins.

Traumatic stress and ways of coping of community residents exposed to a train disaster

OBJECTIVES

The aims of this study were to examine the degree of traumatic stress and the coping strategies employed by community residents who lived on both sides of a rail track where a train collision occurred in 1996 in Stafford, UK. The hypothesis was that there would be a high level of traumatic stress and that emotion-focused coping would be the predictor to distress.

METHOD

This was a cross-sectional survey with a retrospective design in which 66 community residents, who lived between 30 and 100 feet away from the crash site, were interviewed. The study began approximately 7 months after the disaster. The Impact of Event Scale (IES), the General Health Questionnaire (GHQ-28) and the Ways of Coping Checklists (WOC) were administered to the residents.

RESULTS

On the whole, the results did not entirely support the hypothesis. The residents were found to have experienced some intrusive thoughts and avoidance behaviour but their mean scores were significantly lower than those of standardized samples. Thirty-five per cent scored at 4 or above on the GHQ-28. Traumatic stress was predicted by both emotion-focused and problem-focused coping strategies.

CONCLUSION

Although community residents were not on the train or related to the dead or injured in any way, they could, after being exposed to a train disaster, manifest traumatic stress symptoms which had long-lasting effects. Such traumatic stress was found to be associated with coping strategies of community residents characterized by their efforts to manage or alter the source of stress, and by their efforts to regulate stressful emotions.

TFEC can function as a transcriptional activator of the nonmuscle myosin II heavy chain-A gene in transfected cells

Transcription of the human nonmuscle myosin II heavy chain-A (NMHC-A) gene is regulated via multiple elements located in intron 1, including element F which contains an E-box. In this study we have identified and characterized the factors that are capable of binding to element F. Yeast one-hybrid screening using element F allowed isolation of cDNAs encoding transcriptional factors TFEC, TFE3, and USF2, each of which contains basic helix-loop-helix and leucine zipper motifs. Furthermore, cDNA cloning by polymerase chain reaction yielded cDNAs for two TFEC isoforms, designated TFEC-l and TFEC-s, which are generated by alternative pre-mRNA splicing. In addition to these four factors, USF1, which is known to share the same DNA binding elements with USF2, was isolated for comparison. Electrophoretic mobility shift assays and cotransfection studies of the expression constructs with reporter gene constructs revealed that the above five factors have different binding activities for element F with different transactivation potencies. USF1 and USF2 demonstrate the highest binding activity to element F, yet show the lowest element F-dependent transactivation. TFE3 has a high transactivation potency but the lowest binding activity. TFEC-l demonstrates a high binding activity with the highest transactivation potency, whereas TFEC-s has the same binding activity as TFEC-l with intermediate transactivation. We also demonstrate that an N-terminal activation domain exists only in TFEC-l, whereas a C-terminal activation domain is common to both the l and s isoforms. This study provides the first evidence of TFEC being an activator of transcription, with two separate activation domains.

Purification and characterization of a variant of rhodocetin from Calloselasma rhodostoma (Malayan pit viper) venom

Rhodocetin is a novel C-type lectin-related protein (CLP) purified from the venom of Calloselasma rhodostoma. Thus far, it is the only reported CLP whose alpha and beta subunits are not linked by an interdisulfide bond. We report here the isolation of a variant of rhodocetin from a different source of venom. This variant of rhodocetin exhibited a different elution profile in reverse-phase HPLC as compared to the rhodocetin reported in our original publication [Wang et al., (1999), Biochemistry 38, 7584-7593]. Specifically, the alpha subunit of the variant was eluted at a considerably lower percentage of acetonitrile, which suggested a less hydrophobic polypeptide chain as compared to the original rhodocetin. Using a combination of microcharacterization techniques such as peptide mapping, mass spectrometry, and amino acid sequencing, we identified an amino acid substitution, 163K, in the polypeptide chain that could account for the difference in elution behavior of the alpha subunit. In addition, we also found a conserved E88D substitution in the beta chain which was not apparent during reverse-phase HPLC. However, neither of these substitutions resulted in the alteration of the functional properties of the rhodocetin variant.

An integrated approach in the discovery and characterization of a novel nuclear protein over-expressed in liver and pancreatic tumors

An integrated approach in protein discovery through the use of multidisciplinary tools was reported. A novel protein, Hcc-1, was identified by analysis of the hepatocellular carcinoma (HCC)-M cell proteome. The assembled EST sequence of the 210 amino acid novel protein was subsequently confirmed by rapid amplification of cDNA ends (RACE). A total of 687 bp at the 5' untranslated region of Hcc-1 was identified. Promoter activity and several upstream open reading frames (uORFs) were demonstrated at this region. Bioinformatics prediction showed that the first 42 amino acids of the protein is a SAP domain with sequence matches to hnRNP from various vertebrate species. The Hcc-1 protein was localized to the cell nucleus while the gene was localized to chromosome 7q22.1. Hcc-1 cDNA level was increased in pancreatic adenocarcinoma. The level was also increased in well-differentiated hepatocellular carcinoma but decreases as the carcinoma progressed to a poorly differentiated stage.

Peptide mimicking antigenic and immunogenic epitope of double-stranded DNA in systemic lupus erythematosus

Autoantibodies to double-stranded (ds) DNA are an important diagnostic marker and pathogenic factor for systemic lupus erythematosus (SLE). Identifying dsDNA mimotopes is a way to discover diagnostic and therapeutic candidates for SLE. 'Mono-specific' SLE anti-dsDNA antibodies were obtained by affinity purification using dsDNA-coupled Sepharose column. Using the anti-dsDNA antibodies to screen a phage peptide library, we were able to identify a mimotope that has a motif peptide sequence of RLTSSLRYNP. This chemically synthesized peptide could be recognized by 88% (37 out of 42) of anti-dsDNA antibody-positive SLE sera with a cut-off point at mean + 3 SD of the negative control sera at OD(492). The reaction of the peptide with SLE sera in ELISA was highly correlated with that of dsDNA (r = 0.809, P < 0.0001). Of particular interest, not only dsDNA but also single-stranded (ss) DNA and native RNA could inhibit the binding of the peptide with SLE sera, suggesting that the mimotope is shared by ds and ssDNAs as well as native RNA, whereas denatured RNA was not observed to inhibit the binding. The peptide was also able to elicit an immune response in rabbits and the anti-peptide rabbit serum was observed to cross-react with the peptide, ss and dsDNAs, and ss and dsDNAs could inhibit the binding of the anti-peptide serum and the peptide. However, the inhibition was not obtained with RNA. Our findings demonstrate the potential of the peptide mimic in diagnostic tests of SLE, and in the investigation of anti-DNA antibody origin and of DNA-anti-DNA antibody interaction.

Traumatic stress and death anxiety among community residents exposed to an aircraft crash

This article examined the relationship between traumatic stress and death anxiety among community residents who lived near woodlands in which an aircraft had crashed in Coventry, England. The hypothesis was that there would be a high level of impact of the crash experienced by residents and that the residents would experience psychological distress. It was also hypothesized that the impact of the crash and distress were associated with death anxiety. Eighty-two residents were interviewed for the study. They were asked to complete the Impact of Event Scale, the General Health Questionnaire (GHQ), and the Death Anxiety Scale. The results showed that Coventry residents were found to experience intrusive thoughts and display avoidance behavior. The residents' intrusive thoughts and avoidance behavior were significantly more severe than one group of Horowitz's standardized samples (i.e., the medical students), but not significantly different from another group (i.e., the stress clinic samples). Fifty-seven percent scored at or above the GHQ cutoff point, which meant that they were considered to be psychiatric cases. Community residents scored significantly lower in death anxiety than the standardized high-death anxiety patients but no differently from the standardized control patients. Correlations were found between the impact of the event, psychological distress, and death anxiety.

Two-dimensional electrophoresis map of the human hepatocellular carcinoma cell line, HCC-M, and identification of the separated proteins by mass spectrometry

Currently, one of the most popular applications of proteomics is in the area of cancer research. In Africa, Southeast Asia, and China, hepatocellular carcinoma is one of the most common cancers, occurring as one of the top five cancers in frequency. This project was initiated with the purpose of separating and identifying the proteins of a human hepatocellular carcinoma cell line, HCC-M. After two-dimensional gel electrophoresis separation, silver staining, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses, tryptic peptide masses were searched for matches in the SWISS-PROT and NCBI nonredundant databases. Approximately 400 spots were analyzed using this approach. Among the proteins identified were housekeeping proteins such as alcohol dehydrogenase, alpha-enolase, asparagine synthetase, isocitrate dehydrogenase, and glucose-6-phosphate 1-dehydrogenase. In addition, we also identified proteins with expression patterns that have been postulated to be related to the process of carcinogenesis. These include 14-3-3 protein, annexin, prohibitin, and thioredoxin peroxidase. This study of the HCC-M proteome, coupled with similar proteome analyses of normal liver tissues, tumors, and other hepatocellular carcinoma cell lines, represents the first step towards the establishment of protein databases, which are valuable resources in studies on the differential protein expressions of human hepatocellular carcinoma.

Two-dimensional electrophoresis map of the human hepatocellular carcinoma cell line, HCC-M, and identification of the separated proteins by mass spectrometry

Currently, one of the most popular applications of proteomics is in the area of cancer research. In Africa, Southeast Asia, and China, hepatocellular carcinoma is one of the most common cancers, occurring as one of the top five cancers in frequency. This project was initiated with the purpose of separating and identifying the proteins of a human hepatocellular carcinoma cell line, HCC-M. After two-dimensional gel electrophoresis separation, silver staining, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses, tryptic peptide masses were searched for matches in the SWISS-PROT and NCBI nonredundant databases. Approximately 400 spots were analyzed using this approach. Among the proteins identified were housekeeping proteins such as alcohol dehydrogenase, alpha-enolase, asparagine synthetase, isocitrate dehydrogenase, and glucose-6-phosphate 1-dehydrogenase. In addition, we also identified proteins with expression patterns that have been postulated to be related to the process of carcinogenesis. These include 14-3-3 protein, annexin, prohibitin, and thioredoxin peroxidase. This study of the HCC-M proteome, coupled with similar proteome analyses of normal liver tissues, tumors, and other hepatocellular carcinoma cell lines, represents the first step towards the establishment of protein databases, which are valuable resources in studies on the differential protein expressions of human hepatocellular carcinoma.

The compatibility of two generations of American social psychologists

This paper examines Greenwood's (2000) evidence for incompatibility between the early and later American social psychologists on the social conception of cognition, emotion, and behavior. The notion of the autonomy of the individual may offer the key to finding a degree of compatibility between them. Both generations, I argue, fundamentally accept the notion of individual persons as autonomous agents who are able to decide and choose to act and, hence, be responsible for their actions. Philosophical analysis can perhaps inform historians of social psychology on how carefully and critically to reexamine evidence for traditional claims of generational, paradigmatic, and/or foundational splits.

Characterizing the transmission properties of an ion funnel

The characteristic features of ion transmission properties in a radio-frequency (RF) electric-field driven ion funnel using the SIMION ion trajectory simulation package is presented. A user program applying the Douglas ion-neutral collisional drag coefficient model is incorporated to properly account for the ion focusing and transport effect of the background gas under the effect of the driving RF and a superimposed DC field. The simulated m/z transmission window compares favorably with the experimental results reported by Smith et al. RF amplitude and pressure dependence of experimentally observed m/z transmission windows are also examined, and an approximated effective potential model based on Gerlich's equation is proposed to interpret the low-m/z cutoff behavior. A modified ion funnel configuration is described.

Amino acid sequence of trocarin, a prothrombin activator from Tropidechis carinatus venom: its structural similarity to coagulation factor Xa

Among snake venom procoagulant proteins, group II prothrombin activators are functionally similar to blood coagulation factor Xa. We have purified and partially characterized the enzymatic properties of trocarin, the group II prothrombin activator from the venom of the Australian elapid, Tropidechis carinatus (rough-scaled snake). Prothrombin activation by trocarin is enhanced by Ca2+, phospholipids, and factor Va, similar to that by factor Xa. However, its amidolytic activity on peptide substrate S-2222 is significantly lower. We have determined the complete amino acid sequence of trocarin. It is a 46,515-Dalton glycoprotein highly homologous to factor Xa and shares the same domain architecture. The light chain possesses an N-terminal Gla domain containing 11 gamma-carboxyglutamic acid residues, followed by two epidermal growth factor (EGF)-like domains; the heavy chain is a serine proteinase. Both chains are likely glycosylated: the light chain at Ser 52 and the heavy chain at Asn 45. Unlike other types of venom procoagulants, trocarin is the first true structural homologue of a coagulation factor. It clots snake plasma and thus may be similar, if not identical, to snake blood coagulation factor Xa. Unlike blood factor Xa, it is expressed in high quantities and in a nonhepatic tissue, making snake venom the richest source of factor Xa-like proteins. It induces cyanosis and death in mice at 1 mg/kg body weight. Thus, trocarin acts as a toxin in venom and a similar, if not identical, protein plays a critical role in hemostasis.

Rhodocetin, a novel platelet aggregation inhibitor from the venom of Calloselasma rhodostoma (Malayan pit viper): synergistic and noncovalent interaction between its subunits

A novel platelet aggregation inhibitor, rhodocetin, was purified from the crude venom of Calloselasma rhodostoma. It inhibited collagen-induced platelet aggregation in a dose-dependent manner, with an IC50 of 41 nM. Rhodocetin has a heterodimeric structure with alpha and beta subunits, which could be separated on a nonreducing denaturing gel or reverse-phase HPLC column. Individually neither subunit inhibited platelet aggregation even at 2.0 microM concentration. Titration and reconstitution experiments showed that, when these subunits are mixed to give a 1:1 complex, most of its biological activity was recovered. The reconstituted complex inhibited platelet aggregation with an IC50 of 112 nM, about 3-fold less effective than the native molecule. Circular dichroism analysis revealed that the reconstituted complex had a spectrum similar to that of the native protein. By using surface plasmon resonance studies, we established that the stoichiometry of binding between the two subunits is 1:1 and the subunits interact with a Kd of 0.14 +/- 0.04 microM. The complete amino acid sequences of the alpha (15956.16 Da, 133 residues) and beta (15185.10 Da, 129 residues) subunits show a high degree of homology with each other (49%) and with the Ca2+-dependent lectin-related proteins (CLPs) (typically 29-48%) isolated from other snake venoms. Unlike the other members of the family in which the subunits are held together by an interchain disulfide bond, rhodocetin subunits are held together only through noncovalent interactions. The cysteinyl residues forming the intersubunit disulfide bridge in all other known CLPs are replaced by Ser-79 and Arg-75 in the alpha and beta subunits of rhodocetin, respectively. These studies support the noncovalent and synergistic interactions between the two subunits of rhodocetin. This is the first reported CLP dimer with such a novel heterodimeric structure.

The relationship between trauma and personality in victims of the Boeing 737-2D6C crash in Coventry

The aims of this paper were to (a) ascertain the extent of psychological distress and (b) identify the association between personality variables and psychological distress among individuals who had been exposed to an aircraft disaster in Coventry, U.K. Hundreds of people escaped death but were exposed to the impact of the disaster when a Boeing 737-2D6C 7T-VEE crashed into a woodland area on the edge of a large housing estate in Coventry, U.K. in 1994. Eighty-two residents were randomly chosen for interviews in which they were assessed using the Impact of Event Scale, the General Health Questionnaire, and the Eysenck Personality Questionnaire-R Short Scale (EPQ-R). The results showed that the Coventry residents' scores reached similar levels of intrusion and avoidance compared with standardized samples and the Lockerbie samples. Fifty-two percent reached the GHQ case level score, which was again similar to the Lockerbie residents. The Coventry residents were significantly less extroverted and neurotic than standardized samples. Stepwise multiple regression showed that there were associations between intrusion and neuroticism and intrusion and extroversion, as well as between avoidance and neuroticism.

Nursing students' perceptions of their first mental health placement

The way in which the theory and practice of mental health nursing is presented to students is of particular importance, especially at a time when recruitment into the profession is falling. This study sought to examine how nursing students experience their first mental health placement. A pre-/post-test design was used with a standardized instrument (Attitude Towards Psychiatry questionnaire) to assess the influence of their mental health placements on nursing students' attitudes towards mental health nurses, mental health nursing practice and education and theoretical aspects of mental health nursing. Results suggest that the placements were effective in improving students' regard in each of these areas. Though no generalizable conclusions can be inferred from this study some interesting insights are provided by nursing students into their perceptions of current mental health nursing practice.

Identification of Enterobacteriaceae bacteria by direct matrix-assisted laser desorptiom/ionization mass spectrometric analysis of whole cells

Several members of Enterobacteriaceas were analyzed by matrix-assisted laser desorption ionization (MALDI) time-of-flight mass spectrometry (TOFMS). Characteristic mass spectral peaks and patterns were observed in the mass range of 2 to 20 kDa. The mass peaks reported to be reproducibly observed by previous researchers, which were claimed to serve as species/strain-specific biomarkers, are consistently observed in our current study. Despite the high degree of similarity found in the MALDI mass spectra within the enteric bacteria, minor yet notable differences existed to allow their differentiation. Five spectral peaks at m/z 4364, 5380, 6384, 6856, and 9540, generated reproducibly for each genus studied here, are assigned as family-specific biomarkers for the Family Enterobacteriaceae. The mass peaks at m/z 7324, 7724, 9136, and 9253 are assigned as genus-specific biomarkers for Salmonella. Some unique biomarkers characterizing the species and strains of E. coli are also presented.

Describing traumatic responses and distress of community residents directly and indirectly exposed to an aircraft crash

This study described the traumatic responses and the extent of psychological distress among residents who had been exposed directly or indirectly to an aircraft crash in Coventry, U.K. The direct exposure group consisted of 62 residents who were on the housing estate at the time of the accident and 20 who were not. They were interviewed on their subjective responses to the crash and then asked to fill in two distress measures: the Impact of Event Scale (IES) and the General Health Questionnaire (GHQ). The results showed a contrast between the responses of the two groups at the time of the crash. They also showed that the direct exposure group had a significantly higher score in the IES item of avoidance, the IES total, the GHQ items of somatization, social dysfunction, and the total score than the indirect exposure group had. Associations were then made between subjective responses and distress measures. Stepwise multiple regression analyses showed that for the direct exposure residents, the IES total was predicted by "whether they received professional help" and "whether they were worried about their safety after the crash." The GHQ total of the direct exposure residents was predicted by "anger about what had happened to them." For the indirect exposure residents, the IES total was predicted by "their present feelings when they heard planes flying over." There were no predictions found between responses and the GHQ total.

A follow-up study of mentally disordered offenders after a court diversion scheme: six-month and one-year comparison

The aim of this study was to investigate offenders' living patterns, quality of life, types of aftercare received and psychological well-being, following their diversion from one court diversion scheme in England. Sixty-five offenders were followed up after six months, 22 of whom were also followed up after one year. Their transient living patterns throughout these two periods were described. Their quality of life was found to be poor in that most did not have an occupation, nor did they receive education, and the life experiences during both periods were lower than that of standardized urban samples. There were no significant changes in their poor life experiences over the two periods. Over 55% of the 22 offenders still contacted their GPs regularly but there was a significant drop in those consulting hospital doctors. Only a small number of offenders had contact with the social services in these two periods and no significant differences were found between them. Their GHQ total scores went above cutoff point and the level of psychiatric conditions was similar in both periods.

A description of a forensic diversion service in one city in the United Kingdom

This paper describes some recent research on forensic diversion services and the application of such services in Birmingham, UK. Key components include the diversion scheme in court, diversion at point of arrest, and the remand prison liaison scheme. Various community facilities, such as a specialized bail hostel and landlady schemes to which offenders are possibly referred, are also briefly described. We advocate the need for further research in order to examine the effectiveness of the services in Birmingham.

Longitudinal changes in adaptive behavior in adults with Down syndrome: interim findings from a longitudinal study

Age-related changes in adaptive behavior have been established in adults with Down syndrome. However, most studies have been cross-sectional, without controls for cohort and survival effects. We examined underlying factors for age-related decline in adaptive behavior in 128 adults with trisomy 21 over a 3-year period. Presence of dementia was the only determining factor, although the difference in trend over time as compared to subjects without dementia was not significant. No association between gender, sensory loss, severity of mental retardation, or place of residence was found. For subjects with no significant medical disorder (physical or psychological), no decline was seen. This longitudinal study confirms previously reported findings.

The burnout of nursing staff working with challenging behaviour clients in hospital-based bungalows and a community unit

The aim of this pilot study was to compare the burnout of nursing staff who worked with clients who displayed challenging behaviour in hospital-based bungalows and a community unit. Twenty-six and 12 nursing staff were randomly chosen from four hospital-based bungalows and a community unit. Staff assessed their clients' behaviour, using the Aberrant Behavior Checklist and were later interviewed, using a self-constructed Staff Questionnaire and the Maslach Burnout Inventory. The results showed that clients in the hospital-based bungalows were more severe in challenging behaviour than those in the community unit. The staff in the hospital-based bungalows were less satisfied with their salaries and enjoyed less their contact with clients. They complained more than the community unit staff and felt that their present training was inadequate. They were also more emotionally exhausted and experienced more depersonalization towards clients than the community unit staff. The level of personal accomplishment was, however, similar in the two groups. Correlations showed that there were significant associations between staff burnout and management issues rather than clients' behaviour, particularly in the hospital-based bungalow group.

Genomic structure of a potassium channel toxin from Heteractis magnifica

We provide information on the gene encoding the K+ channel toxin, HmK, of the sea anemone Heteractis magnifica. A series of DNA amplifications by PCR, which included the amplification of the 5'-untranslated region of the gene, showed that an intron of 402 nucleotides separated the sequence that encodes the matured toxin from the signal peptide sequence. A second 264 nucleotide intron interrupted the 5'-untranslated region of the previously reported HmK cDNA. Two possible transcription-initiation sites were identified by primer extension analysis. Corresponding TATA-box consensus sequences, characteristic of a promoter region, were also located from PCR products of uncloned libraries of adaptor-ligated genomic DNA fragments. The coding region for matured HmK is intronless. The same is also true for other sea anemone toxins reported thus far. More notably, a similar intron-exon organization is present in other ion channel-blocking toxins from scorpions implying that molecules having similar functions share a similar organization at the genomic level suggesting a common path of evolution.

Synthesis and in vitro evaluation of potential antichagasic dipeptide prodrugs of primaquine

American trypanosomiasis (Chagas' disease) is an endemic parasitic disease afflicting more than 20 million people in Latin America. Currently, therapy is unsatisfactory and only two drugs are available. Primaquine, an antimalarial drug, has trypanocidal activity. Dipeptide derivatives of primaquine, Phe-Arg-PQ, Lys-Arg-PQ, and Phe-Ala-PQ, were synthesized. The choice of the peptides was based on the primary specificity of cruzipain, the major cysteine proteinase from T cruzi. The prodrugs obtained were tested on the LLC-MK2 cell culture infected with trypomastigotes forms of T. cruzi. Phe-Arg-PQ, Lys-Arg-PQ, and Phe-Ala-PQ were active in all stages.

A new potassium channel toxin from the sea anemone Heteractis magnifica: isolation, cDNA cloning, and functional expression

A new potassium channel toxin, HmK, has been isolated from the sea anemone Heteractis magnifica. It inhibits the binding of [125I]-alpha-dendrotoxin (a ligand for voltage-gated K channels) to rat brain synaptosomal membranes with a Ki of about 1 nM, blocks K+ currents through Kv 1.2 channels expressed in a mammalian cell line, and facilitates acetylcholine release at the avian neuromuscular junction. HmK comprises of 35 amino acids (Mr 4055) with the sequence R1TCKDLIPVS10ECTDIRCRTS20MKYRLNLCRK30TCGSC35. A full assignment of the disulfide linkages was made by using partial reduction with tri(2-carboxyethyl)phosphine (TCEP) at acid pH and rapid alkylation with iodoacetamide. The disulfide bridges were identified as Cys3-Cys35, Cys12-Cys28, and Cys17-Cys32. A cDNA clone encoding HmK was isolated using RT-PCR from the total RNA obtained from sea anemone tentacles, while the 5'- and 3'-flanking regions of the cDNA were amplified by RACE. The full-length cDNA was 563 bp long and contained a sequence encoding a signal peptide of 39 amino acids. The coding region for matured HmK toxin was cloned and expressed as a glutathione S-transferase (GST) fusion product in the cytoplasm of Escherichia coli. After affinity purification and cleavage, the recombinant toxin was shown to be identical to native HmK in its N-terminal sequence, chromatographic behavior, and binding to dendrotoxin binding sites on rat brain membranes.

Rabbit ubiquitin-activating enzyme E1: cDNA cloning, sequence and expression

A cDNA clone encoding ubiquitin-activating enzyme E1 has been isolated from a rabbit heart cDNA library and sequenced. The 3.485 kb cDNA contains an open reading frame of 1058 amino acid residues which predicts a protein of approx. 118 kDa. The deduced protein sequence exhibits a very high homology to other ubiquitin-activating enzymes identified in a variety of organisms. Northern blot analysis reveals a single transcript of approx. 3.5 kb in all the rabbit tissues examined. The entire coding region of the rabbit E1 cDNA has been expressed as a his-tagged protein. The recombinant protein has been verified by its ability to cross-react with anti-human E1 antibodies. Ubiquitin thiolester assay shows that the recombinant rabbit E1 protein is functional.

Proteolytic specificity of rhodostoxin, the major hemorrhagin of Calloselasma rhodostoma (Malayan pit viper) venom

The proteolytic specificity of rhodostoxin, the major hemorrhagin from Calloselasma rhodostoma (Malayan pit viper) venom was investigated using oxidized B-chain of bovine insulin as substrate. Six peptide bonds were cleaved: Ser9-Hist10, His10-Leu11, Ala14-Leu15, Tyr16-Leu17, Gly20-Glu21 and Phe24-Phe25. Deglycosylated rhodostoxin, however, cleaved primarily at Arg22-Gly23.

MR566A and MR566B, new melanin synthesis inhibitors produced by Trichoderma harzianum. II. Physico-chemical properties and structural elucidation

New melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum, and their structures were elucidated by spectroscopic methods. The structures of novel isocyanides, MR566A (1) and B (2), were elucidated as 1-(3-chloro-1,2-dihydroxy-4-isocyano-4-cyclopenten-1-yl)etha nol, 1-(1,2,3-trihydroxy-3-isocyano-4-cyclopenten-1-yl)ethanol, respectively. The structure of novel oxazole, MR93B (9), was elucidated as 4-[(1Z)-3-hydroxy-2-hydroxymethyl-1-propen-1-yl]oxazole.

MR566A and MR566B, new melanin synthesis inhibitors produced by Trichoderma harzianum. I. Taxonomy, fermentation, isolation and biological activities

New melanin synthesis inhibitors (MR566A and B) and six related known isocyanocyclopentenes were isolated from the fermentation broth of Trichoderma harzianum. The IC50 values of MR566A and B against mushroom tyrosinase were 1.72 and 47 microM, respectively. They inhibited melanin biosynthesis in B16 melanoma cells with MIC values of 0.1 and 2.2 microM, respectively. Also isolated from the same culture extract of T. harzianum was a new oxazole (MR93B), which showed no inhibitory activity against mushroom tyrosinase at a concentration of 1,000 microg/ml.

Adrenergic and nitrergic responses of the rat isolated anococcygeus muscle to a new toxin (makatoxin I) from the venom of the scorpion Buthus martensi Karsch

1. Makatoxin I (MkTx I) is a new toxin purified from the venom of the scorpion Buthus martensi Karsch. Contractile (excitatory, adrenergic) and relaxant (inhibitory, nitrergic) responses of the rat isolated anococcygeus muscle (Acm) to MkTx I were investigated. 2. MkTx I (0.28 microM) produced a rapid and very marked rise in the tone of the Acm which then gradually wanted to the control baseline. Phentolamine (5 microM), guanethidine (5 microM), tetrodotoxin (2 microM) and reserpine pretreatment in vivo (5 mg kg-1 s.c. at 24 hr and 5 mg kg-1 i.p. at 3 h) completely blocked the contractile responses of the Acm to MkTx I. The responses to noradrenaline (NA) were blocked by phentolamine, but were potentiated by guanethidine. 3. MkTx I (0.28 microM) also marked and rapidly relaxed the tone of the carbachol (CCh; 3 microM), precontracted Acm. The addition of sodium nitroprusside (SNP; 1 microM) also produced a marked and rapid relaxation of the Acm. TTx (2 microM) or NG-nitro-L-arginine methylester (L-NAME, 50 microM) markedly inhibited the relaxant responses of the Acm to field stimulation (FS) as well as to MkTx I, but not the responses to SNP. 4. Therefore, the contractile responses of the rat anococcygeus muscle to MkTx I can be attributed to the release of transmitter NA on postjunctional alpha-adrenoceptors, whereas the relaxant responses of the Acm to MkTx I involve the release of nitric oxide as the neurotransmitter which, presumably, results in the activation of the enzyme guanylate cyclase leading to relaxation of the muscle.