Cigarette toxicity triggers Leber's hereditary optic neuropathy by affecting mtDNA copy number, oxidative phosphorylation and ROS detoxification pathways.

Leber's hereditary optic neuropathy (LHON), the most frequent mitochondrial disease, is associated with mitochondrial DNA (mtDNA) point mutations affecting Complex I subunits, usually homoplasmic. This blinding disorder is characterized by incomplete penetrance, possibly related to several genetic modifying factors. We recently reported that increased mitochondrial biogenesis in unaffected mutation carriers is a compensatory mechanism, which reduces penetrance. Also, environmental factors such as cigarette smoking have been implicated as disease triggers. To investigate this issue further, we first assessed the relationship between cigarette smoke and mtDNA copy number in blood cells from large cohorts of LHON families, finding that smoking was significantly associated with the lowest mtDNA content in affected individuals. To unwrap the mechanism of tobacco toxicity in LHON, we exposed fibroblasts from affected individuals, unaffected mutation carriers and controls to cigarette smoke condensate (CSC). CSC decreased mtDNA copy number in all cells; moreover, it caused significant reduction of ATP level only in mutated cells including carriers. This implies that the bioenergetic compensation in carriers is hampered by exposure to smoke derivatives. We also observed that in untreated cells the level of carbonylated proteins was highest in affected individuals, whereas the level of several detoxifying enzymes was highest in carriers. Thus, carriers are particularly successful in reactive oxygen species (ROS) scavenging capacity. After CSC exposure, the amount of detoxifying enzymes increased in all cells, but carbonylated proteins increased only in LHON mutant cells, mostly from affected individuals. All considered, it appears that exposure to smoke derivatives has a more deleterious effect in affected individuals, whereas carriers are the most efficient in mitigating ROS rather than recovering bioenergetics. Therefore, the identification of genetic modifiers that modulate LHON penetrance must take into account also the exposure to environmental triggers such as tobacco smoke.

A long-term study examining the antibacterial effectiveness of Agion silver zeolite technology on door handles within a college campus.

Laboratory studies have shown that small concentrations of silver are effective at inhibiting the growth micro-organisms through the disruption of important cell structures and processes. The additional ability to incorporate silver into surfaces has increased the usage of silver in the medical field and expanded its use into the consumer market. To understand the impact of increased silver-containing antimicrobial use, it is important to determine whether silver-based consumer goods are effective at reducing bacterial populations. Our study examined the antibacterial effectiveness of Agion silver zeolite technology applied to 25 silver- and control-coated door handles across a college campus. Door handles were sampled for 6 week periods in both the fall and spring semester, and bacteria were cultured and enumerated on tryptic soy agar (TSA), MacConkey agar (MAC) and mannitol salt agar (MSA). A significant difference was observed between the bacterial populations isolated from silver- and control-coated door handles after 3 years. However, bacteria were consistently isolated from silver-coated door handles suggesting that the silver zeolite was only effective against a portion of the bacterial populations, and further studies are necessary to determine the identities of the isolated bacteria and the prevalence of silver resistance.

El bloqueo neuromuscular residual como factor de riesgo para eventos críticos respiratorios en la Unidad de Recuperación Postanestésica / Residual neuromuscular block as a risk factor for critical respiratory events in the post anesthesia care unit

Objetivo. El bloqueo neuromuscular residual es una importante complicación postoperatoria asociada al uso de fármacos bloqueantes neuromusculares. El objetivo de este estudio fue valorar la incidencia de bloqueo neuromuscular residual en una unidad de recuperación postanestésica (URPA) y evaluar su asociación con eventos respiratorios críticos. Material y métodos. Estudio de cohortes, prospectivo realizado en una URPA durante un período de 3 semanas. Se incluyó a doscientos dos pacientes adultos sometidos a cirugía programada no cardiaca no-intracraneal. La variable de resultado principal fue la presencia de bloqueo neuromuscular residual después del ingreso en unidad de recuperación postanestésica definido como un cociente del tren de cuatro estímulos-TOFr<0,9 y objetivamente cuantificado usando aceleromiografía. Se registraron datos demográficos, variables perioperatorias, tiempo de permanencia en la unidad, tiempo de estancia hospitalaria y complicaciones respiratorias. La recuperación inadecuada se clasificó de acuerdo con la escala de agitación y sedación de Richmond 10 minutos después del ingreso en la unidad. Resultados. La incidencia de bloqueo neuromuscular residual en la URPA fue de 29,7% (Intervalo de Confianza 95%: 23,4 - 36,1). Los pacientes con bloqueo residual tuvieron eventos respiratorios críticos, considerados de forma global con mayor frecuencia (51% frente 16%, p<0,001), obstrucción de vía aérea (10% frente 2%, p=0,029), hipoxemia leve-moderada (23% frente 4%, p<0,001), hipoxemia grave (7% frente 1%, p=0,033), insuficiencia respiratoria(8% frente 1%, p=0,031), incapacidad para respirar profundamente (38% frente 12%, p<0,01) y debilidad muscular (16% frente 1%, p<0,001). El bloqueo neuromuscular residual fue más frecuente después de cirugía de alto riesgo (53% frente 33%, p=0,011) y se asociaba más a menudo con recuperación anestésica hipoactiva según lo definido por la escala de agitación y sedación de Richmond (21% frente 6%, p=0,001). Conclusiones. Este estudio sugiere que el bloqueo neuromuscular residual es común en la URPA y se asocia a mayor frecuencia de incidentes respiratorios críticos(AU)

Objective. Residual neuromuscular block is an important postoperative complication associated to the use of neuromuscular blocking drugs. The purpose of this study was to access the incidence of residual neuromuscular block in a post-anesthesia care unit and to evaluate its association with critical respiratory events. Material and methods. Prospective cohort study was conducted in a Post Anesthetic Care Unit (PACU) for a period of 3 weeks. Two hundred two adult patients who submitted to scheduled non-cardiac and non-intracranial surgery were eligible to the study. The primary outcome variable was residual neuromuscular block after arrival to PACU that was defined as train-of-four ratio <0.9 and objectively quantified using acceleromyography. Demographic data, perioperative variables, lengths of hospital and recovery room stay and critical respiratory events were recorded. Inadequate emergence was classified in its different forms according to the Richmond agitation and sedation scale 10min after admission to the recovery room. Results. Residual neuromuscular block incidence in the post-anesthesia care unit was 29.7% (95% confidence interval: 23.4, 36.1). Patients with residual neuromuscular block had more frequently overall critical respiratory events (51% versus 16%, P<0.001), airway obstruction (10% versus 2%, P=0.029), mild-moderate hypoxemia (23% versus 4%, P<0.001), severe hypoxemia (7% versus 1%, P=0.033), respiratory failure (8% versus 1%, P=0.031), inability to breathe deeply (38% versus 12%, P<0.001) and muscular weakness (16% versus 1%, P<0.001). Residual neuromuscular block was more common after high-risk surgery (53% versus 33%, P=0.011) and was more often associated with post-operative hypoactive emergence as defined by the Richmond Agitation and Sedation Scale (21% versus 6%, P=0.001). Conclusions. This study suggests that residual neuromuscular block is common in the PACU and is associated with more frequent critical respiratory events(AU)

[Economic impact of the resolution of drug related problems in an Emergency Department]. / Impacto económico de la resolución de problemas relacionados con medicamentos en un servicio de urgencias.

OBJECTIVE: Determine the economic impact of avoided cost in hospital stays by preventing drug-related problems. METHOD: Prospective observational study of six months in the emergency department. We included patients admitted for observation and pre-admission beds. A pharmacist was integrated into the healthcare team to validate / reconcile pharmacotherapy. Severity was associated DRPs detected / resolved with the risk increasing the stay of patients admitted to a clinical unit, estimating the potential cost avoided. RESULTS: El 32,5% of patients required intervention and were intercepted 444 drug-related problems, resolving 85.5%. Serious problems serious / significant unresolved affected 130 patients who were admitted, with an estimated avoided cost about 60,000 €. It was noted that serious problems and oral cytostatics, insulin and diabetes were the groups associated with a higher average cost avoided (p <0.05). CONCLUSION: The integration of the pharmacist in the emergency team to intercept medication problems, reducing the risk of stay and increase healthcare costs.

Residual neuromuscular block as a risk factor for critical respiratory events in the post anesthesia care unit.

OBJECTIVE: Residual neuromuscular block is an important postoperative complication associated to the use of neuromuscular blocking drugs. The purpose of this study was to access the incidence of residual neuromuscular block in a post-anesthesia care unit and to evaluate its association with critical respiratory events. MATERIAL AND METHODS: Prospective cohort study was conducted in a Post Anesthetic Care Unit (PACU) for a period of 3 weeks. Two hundred two adult patients who submitted to scheduled non-cardiac and non-intracranial surgery were eligible to the study. The primary outcome variable was residual neuromuscular block after arrival to PACU that was defined as train-of-four ratio <0.9 and objectively quantified using acceleromyography. Demographic data, perioperative variables, lengths of hospital and recovery room stay and critical respiratory events were recorded. Inadequate emergence was classified in its different forms according to the Richmond agitation and sedation scale 10 min after admission to the recovery room. RESULTS: Residual neuromuscular block incidence in the post-anesthesia care unit was 29.7% (95% confidence interval: 23.4, 36.1). Patients with residual neuromuscular block had more frequently overall critical respiratory events (51% versus 16%, P<0.001), airway obstruction (10% versus 2%, P=0.029), mild-moderate hypoxemia (23% versus 4%, P<0.001), severe hypoxemia (7% versus 1%, P=0.033), respiratory failure (8% versus 1%, P=0.031), inability to breathe deeply (38% versus 12%, P<0.001) and muscular weakness (16% versus 1%, P<0.001). Residual neuromuscular block was more common after high-risk surgery (53% versus 33%, P=0.011) and was more often associated with post-operative hypoactive emergence as defined by the Richmond Agitation and Sedation Scale (21% versus 6%, P=0.001). CONCLUSIONS: This study suggests that residual neuromuscular block is common in the PACU and is associated with more frequent critical respiratory events.

Impacto económico de la resolución de problemas relacionados con medicamentos en un servicio de urgencias / Economic impact of the resolution of drug related problems in an Emergency Department

OBJETIVO: Determinar el impacto económico del coste evitado en estancias hospitalarias a través de la prevención de problemas relacionados con los medicamentos. MÉTODO: Estudio observacional prospectivo de seis meses en un Servicio de Urgencias. Se incluyeron a pacientes hospitalizados en camas de observación y preingreso. Un farmacéutico se integró en el equipo asistencial para validar/ conciliar la farmacoterapia. Se asoció la gravedad de los PRM detectados/ resueltos con el riesgo incrementar la estancia de los pacientes que ingresaron en una unidad clínica, estimando el coste potencialmente evitado. RESULTADOS: El 32,5% de los pacientes requirieron intervención y se interceptaron 444 problemas relacionados con medicamentos, resolviéndose el 85,5%. Problemas de gravedad seria/ significativa resueltos afectaron a 130 pacientes que ingresaron, estimándose un coste evitado de unos 60.000 €. Se observó que los problemas serios y los citostáticos orales, insulinas y antidiabéticos fueron los grupos asociados a un coste medio evitado mayor (p < 0,05). CONCLUSIÓN: La integración del farmacéutico en el equipo de Urgencias permite interceptar problemas de medicación, reduciéndose el riesgo de incrementar la estancia y los costes sanitarios

OBJECTIVE: Determine the economic impact of avoided cost in hospital stays by preventing drug-related problems. METHOD: Prospective observational study of six months in the emergency department. We included patients admitted for observation and preadmission beds. A pharmacist was integrated into the healthcare team to validate / reconcile pharmacotherapy. Severity was associated DRPs detected / resolved with the risk increasing the stay of patients admitted to a clinical unit, estimating the potential cost avoided. RESULTS: El 32,5% of patients required intervention and were intercepted 444 drug-related problems, resolving 85.5%. Serious problems serious / significant unresolved affected 130 patients who were admitted, with an estimated avoided cost about 60,000 €. It was noted that serious problems and oral cytostatics, insulin and diabetes were the groups associated with a higher average cost avoided (p <0.05). CONCLUSION: The integration of the pharmacist in the emergency team to intercept medication problems, reducing the risk of stay and increase healthcare costs

Avaliação da atividade antiedematogênica, antimicrobiana e mutagênica das sementes de Amburana cearensis (A. C. Smith) (Imburana-de-cheiro) / Assessment of the antiedematogenic, antimicrobial and mutagenic activity of Amburana cearensis seeds (A.C. Smith) (Imburana-de-cheiro)

Foram avaliados os efeitos antiinflamatório, antibacteriano e mutagênico do extrato aquoso das sementes de Amburana cearensis. A atividade antiinflamatória foi avaliada em modelo de edema de pata induzido por carragenina, utilizando o extrato em concentrações de 10 % e 20 % nos grupos experimentais; AAS 10 mg/kg (v.o) no grupo padrão e água destilada no grupo controle. A atividade antimicrobiana foi determinada através do método de diluição em Agar, utilizando concentrações de extrato de 10 %, 7,5 %, 5 %, 2,5 % e 1 % em cepas de Sthaphylococcus aureus ATCC 27853, Escherichia coli ATCC 25922 e Pseudomonas aeruginosas ATCC 25923) e a atividade mutagênica foi determinada pelo teste de Allium cepa, utilizando extrato em concentrações de 0,02 mg/mL, 0,1 mg/mL e 0,5 mg/mL. O extrato aquoso das sementes de Amburana cearensis nas concentrações de 10 % e 20 % apresentou efeito antiedematogênico, estatisticamente significativo a partir de duas horas após administração do flogógeno, e tal efeito persistiu até 24 horas após a indução da resposta inflamatória. Quanto à atividade antibacteriana, o extrato não apresentou ação contra as cepas bacterianas de Sthaphylococcus aureus, Escherichia coli e Pseudomonas aeruginosas nas concentrações testadas. A análise dos resultados do teste de Allium cepa evidenciou ação tóxica (em concentração de 0,5 mg/mL) e mutagênica (micronúcleo 0,1 mg/mL e aberrações cromossômicas 0,1 mg/mL e 0,5 mg/mL) do extrato de Amburana cearensis em células meristemáticas de Allium cepa. Tais resultados sugerem potencial aplicação terapêutica no tratamento da inflamação. Contudo, também demonstram a necessidade de estudar para comprovar a segurança na utilização dessa espécie.

The anti-inflammatory, antibacterial and mutagenic effects of the aqueous extract of Amburana cearensis seeds were evaluated. The anti-inflammatory activity was evaluated by a paw edema model induced by carrageenan, using the extract at 10 % and 20 % concentrations in the experimental groups: AAS 10 mg/kg (orally administrated) in the standard group and distilled water in the control group. The antimicrobial activity was determined by the agar dilution method, using extract concentrations of 10 %, 7.5 %, 5 %, 2.5 % and 1% in strains of Staphylococcus aureus ATCC 27853, Escherichia coli ATCC 25922 and Pseudomonas aeruginosas ATCC 25923), and the mutagenic activity was determined by the Allium cepa test using extract concentrations of 0,02 mg/mL, 0,1 mg/mL and 0,5 mg/mL. The aqueous extract of Amburana cearensis seeds at 10 % and 20 % concentrations had an statistically significant antiedematogenic effect two hours after administering the flogogen, and this effect persisted for up to 24 hours after inducing the inflammatory response. Regarding the antibacterial activity, the extract showed no action against the bacterial strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosas at the concentrations tested. The results of the Allium cepa test showed the toxic (at a concentration of 0,5 mg/mL) and mutagenicity (0.1 mg/mL micronucleus and 0.1 mg/mL and 0.5 mg/mL chromosomal aberrations) actions of the Amburana cearensis extract on meristematic cells of Allium cepa. These results suggest potential therapeutic applications to treat inflammations. However, they also show the need for further studies to demonstrate the safe use of this species.

Pulmonary arterial hypertension: an imaging review comparing MR pulmonary angiography and perfusion with multidetector CT angiography.

Pulmonary hypertension (PH) is a progressive disease that leads to substantial morbidity and eventual death. Pulmonary multidetector CT angiography (MDCTA), pulmonary MR angiography (MRA) and MR-derived pulmonary perfusion (MRPP) imaging are non-invasive imaging techniques for the differential diagnosis of PH. MDCTA is considered the gold standard for the diagnosis of pulmonary embolism, one of the most common causes of PH. MRA and MRPP are promising techniques that do not require the use of ionising radiation or iodinated contrast material, and can be useful for patients for whom such material cannot be used. This review compares the imaging aspects of pulmonary MRA and 64-row MDCTA in patients with chronic thromboembolic or idiopathic PH.

The high expression of p53 in sporadic colorectal carcinoma is associated with metastasis and decreased survival.

INTRODUCTION: Alteration in the p53 tumour suppressor gene is an event that occurs frequently in human cancer, although its role as predictive and/or prognostic marker is still unclear. The aim of this study was to compare the expression profiles of p53 in colorectal carcinoma with clinicopathological features and survival rate at 5 years from diagnosis. METHODS: One hundred and twenty cases of primary sporadic colorectal cancers (CRCs) and 80 matched normal mucosas were analyzed by immunohistochemistry on paraffin-embedded specimens. The correlation between protein expression profiles, clinicopathological parameters and survival was investigated. RESULTS: In tumour tissues, the expression of p53 was high in 41 cases, low in 38 and negative in 41. A significant correlation was observed between increased p53 expression presence of lymph node (p = 0.002) or liver metastasis (p = 0.008). Moreover, higher levels of p53 were related with advanced tumour stage (III-IV; p = 0.007), poor survival and disease recurrence (p < 0.01). Interestingly, in multivariate analysis p53 expression and distant metastasis were independent prognostic markers. DISCUSSION: Our results suggest that nuclear p53 accumulation in sporadic CRC may have prognostic significance and contribute to identification of patients at high risk of mortality. The current findings may be relevant for management of patients with CRC.

Implicit and explicit memory in junior high and college students.

This study compared the performance of 25 seventh and eighth grade boys and girls on tests of implicit and explicit memory to that of 34 men and women in college. The latter performed significantly better on the explicit memory test. Young adolescents showed a significant priming effect on the implicit memory test; college students did not. Findings suggest a ceiling effect for college students. The results support the distinction between implicit and explicit memory.

Materialism and credit card use by college students.

Much has been written in the popular press on credit card use and spending patterns of American college students. The proliferation of credit cards and their ease of acquisition ensure that students today have more opportunities for making more credit purchases than any other generation of college students. Little is known about the relationship between students' attitudes towards materialism and their use of credit cards. A study was conducted at three college campuses in the northeastern part of the United States where a total of 1,022 students were surveyed. Students' attitudes toward use of credit and their credit card balances were evaluated relative to their scores on Richins and Dawson's Materialism Scale (1992). Our findings suggest no significant difference between those individuals scoring high versus low on the Materialism Scale in terms of the number of credit cards owned and the average balance owed. Individuals high on materialism, however, significantly differed in terms of their uses for credit cards and their general attitude toward their use.

Influence of aerobic and stretching exercise on anxiety and sensation-seeking mood state.

This study randomly assigned participants to either an aerobic, non-aerobic, or lecture group to assess whether one bout of exercise would alter mood state. Regardless of experimental condition, changes in mood state were found on the Sensation Seeking and Anxiety State Tests, where sensation-seeking scores increased and anxiety state decreased from pre- to posttest.

Capillary electrophoresis of supercoiled DNA molecules: parameters governing the resolution of topoisomers and their separation from open forms.

We describe the separation of covalently closed and open circular DNA forms with capillary electrophoresis. This technique is expected to be applied in the research of novel anticancer molecules targeting the activity of topoisomerase I. The separation of a plasmid mixture containing fully supercoiled molecules, single topoisomers, and their relaxed and open circular forms was tested in an electric field of 200 V/cm using Tris/borate buffer with the addition of magnesium ions at low concentrations and various sieving polymers. The resulting separation is quite simple to achieve and is clearly comparable to that obtained in agarose gels run at low voltage, but with an improved resolution, a higher quantitativity, and a higher speed of analysis. We identified three main parameters that influence the separation: (I) Low concentrations of MgCl2 in the separation buffer are required for a good resolution of topoisomers. (II) Cellulose derivatives can be used as sieving polymers; in our hands, HPMC and HEC worked best. (III) High molecular mass forms of sieving polymers allow the best separations.

Production and characterisation of a recombinant single-chain anti ErbB2-clavin immunotoxin.

We generated a recombinant immunotoxin, named scFv(MGR6)-Cla, composed of the Fv region of an anti ErbB2 monoclonal antibody (MGR6) fused to clavin, a type 1 ribosome-inactivating protein (RIP) from Aspergillus clavatus. ErbB2 is a tyrosine kinase receptor which is overexpressed in most adenocarcinomas; clavin is a 17 kDa ribonuclease which inhibits protein synthesis by inactivating ribosomes. A recombinant DNA construct containing the cDNA of the single chain Fv fragment (scFv) of the MGR6 antibody fused to the clavin cDNA, was expressed at high levels in Escherichia coli as an insoluble fusion protein containing an N-terminal affinity tag of six consecutive histidine residues. Inclusion bodies were denatured and the recombinant fusion protein was purified under denaturing conditions by single-step purification using immobilised metal ion affinity chromatography (IMAC). The purified immunotoxin was renatured at high yield and histidine tag removed by digestion with enterokinase. The purity of the immunotoxin obtained after refolding was confirmed by SDS-PAGE, RP-HPLC, GPC-HPLC and N-terminal sequence analysis. Cell-free protein synthesis inhibition and binding assays showed that both clavin and scFv(MGR6) maintained their properties after refolding.

Overproduction of soluble, extracellular cytotoxin alpha-sarcin in Escherichia coli.

The goal of the present study was to establish the condition to obtain preparative amounts of the recombinant cytotoxin alpha-sarcin to be used for immunoconjugate production. alpha-Sarcin cDNA was isolated from Aspergillus giganteus strain MDH 18,894 and its expression in Escherichia coli was attempted by the use of both two-cistron and fusion protein-expression systems. Whereas the former resulted in low intracellular expression level of recombinant alpha-sarcin (r-Sar), the latter allowed high-level expression of the fusion protein in the culture supernatant. A variant form of alpha-sarcin with an additional threonine residue in position 1 (Thr-Sar) was obtained by proteolytic processing of the fusion protein with a final yield after purification of 40 mg/L of culture. Both recombinant proteins r-Sar and Thr-Sar were identical to native a-sarcin with respect to the biochemical properties and to the in vitro biological activity.

Role of cross-linking agents in determining the biochemical and pharmacokinetic properties of Mgr6-clavin immunotoxins.

Several immunotoxins (ITs) were synthesized by the attachment of clavin, a recombinant toxic protein derived from Aspergillus clavatus, to the monoclonal antibody Mgr6 that recognizes an epitope of the gp185(HER-2) extracellular domain expressed on breast and ovarian carcinoma cells. Conjugation and purification parameters were analyzed in an effort to optimize the antitumor activity and stability of the ITs in vivo. To modulate the in vitro and in vivo properties of the immunotoxins, different coupling procedures were used and both disulfide and thioether linkages were obtained. Unhindered and hindered disulfide with a methyl group linkage ethyl S-acetyl 3-mercaptopropionthioimidate ester hydrochloride (AMPT) or ethyl S-acetyl 3-mercaptobutyrothioimidate ester hydrochloride (M-AMPT) were obtained by reaction with recombinant clavin, while the monoclonal antibody Mgr6 was derivatized with ethyl 3-[(4-carboxamidophenyl)dithio]propionthioimidate ester hydrochloride (CDPT). To achieve higher hindrance (a disulfide bond with a geminal dimethyl group), Mgr6 was derivatized with the N-hydroxysuccinimidyl 3-methyl-3-(acetylthio)butanoate (SAMBA) and clavin with CDPT. To evaluate the relevance of the disulfide bond in the potency and pharmacokinetic behavior of the ITs, a conjugate consisting of a stable thioether bond was also prepared by derivatizing Mgr6 with the N-hydroxysuccinimidyl ester of iodoacetic acid (SIA) and clavin with AMPT. The immunotoxins were purified and characterized using a single-step chromatographic procedure. Specificity and cytotoxicity were assayed on target and unrelated cell lines. The data indicate that the introduction of a hindered disulfide linkage into ITs has little or no effect on antitumor activity and suggest that disulfide cleavage is essential for activity; indeed, the intracellularly unbreakable thioether linkage produced an inactive IT. Analysis of IT stability in vitro showed that the release of mAb by incubation with glutathione is proportional to the presence of methyl groups and increases exponentially with the increase in steric hindrance. Analysis of the pharmacokinetic behavior of ITs in Balb/c mice given intravenous bolus injections indicated that ITs with higher in vitro stability were eliminated more slowly; i.e., the disulfide bearing a methyl group doubled the beta-phase half-life (from 3.5 to 7.1 h) compared with that of the unhindered, while a geminal dimethyl protection increased the elimination phase to 24 h. The thioether linkage showed its intrinsic stability with a beta-phase half-life of 46 h. The thioether linkage also increased the distribution phase from 17 to 32 min. The in vitro characteristics and in vivo stability of Mgr6-clavin conjugates composed of a methyl and dimethyl steric hindered disulfide suggest clinical usefulness.

Clavin, a type-1 ribosome-inactivating protein from Aspergillus clavatus IFO 8605. cDNA isolation, heterologous expression, biochemical and biological characterization of the recombinant protein.

We describe the cloning and expression of a new cDNA from the filamentous fungus Aspergillus clavatus IFO 8605. This cDNA contains an open reading frame (ORF) that predicts a putative ribonuclease precursor with high similarity to the alpha-sarcin family of ribosome-inactivating proteins (RIPs). The cDNA encoding the mature protein was expressed in Escherichia coli, and the recombinant protein, a 17-kDa polypeptide designated clavin was purified and characterized. Clavin shows typical type-1 RIP properties: specific cleavage of ribosomal and synthetic RNA and inhibition of protein synthesis in cell-free and cellular systems. When selectively targeted to a tumour cell antigen by coupling to a monoclonal antibody (mAb) clavin was able to inhibit protein synthesis at nanomolar concentration. Pharmacokinetics analysis in mice indicated an elimination half-life (t1/2 beta) of 7.4 h with no particular accumulation in major organs. Liver toxicity was very limited and transient while no alteration of kidney function was observed. Clavin induced a late and very low antibody response in mice. The in vitro and in vivo biological characteristics of clavin, together with its availability in large amounts, suggest the usefulness of this toxin in the production of toxic chemical conjugates.

POEMS syndrome: follow-up study of a case.

We report here the case of a 20-year-old man with POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, M proteins, skin changes). This rare syndrome followed a 3-year history of a syndrome that mimics a chronic inflammatory demyelinating polyneuropathy (CIDP). Treatment with cyclophosphamide induced regression of the syndrome and improved peripheral nerve conduction.

Prochymosin expression in Bacillus subtilis.

Prochymosin (PC) sequence was cloned in Bacillus subtilis using two kinds of plasmid constructions. In plasmid pSM316 the cDNA was inserted to obtain the intracellular expression of the enzyme. The enzyme turned out to be expressed in an insoluble form which could be converted to native enzyme under proper denaturing and refolding conditions. The levels of intracellular expression of PC were further enhanced by modifying the 5' region of the gene in a way that a two-cistron expression system was created. For the PC secretion, the cDNA was fused to the subtilisin leader sequence and expressed under the control of the B. subtilis neutral protease promoter. A properly folded PC was secreted by the cells, although to low levels.