Postnatal cytomegalovirus infection and pulmonary vascular disease in extremely premature infants: A case series

BACKGROUND

Pulmonary vascular disease (PVD) is a major determinant of both morbidity and mortality in extremely low birth weight infants. It is biologically plausible that postnatal cytomegalovirus (pCMV) infection may lead to PVD in premature infants secondary to pneumonitis or via derangement of pulmonary vascular development directly through endothelial dysfunction. Uncertainty remains, however, regarding thresholds for intervention in premature infants with cardiorespiratory instability and presumed CMV infection likely secondary to the limited understanding of the natural history of the disease.

METHODS/RESULTS

We describe four cases of premature infants with clinical and echocardiography features of PVD, in the setting of postnatally acquired CMV. All patients had atypical PVD trajectories, refractory to vasodilator treatment, which improved after initiation of CMV treatment.

CONCLUSION

We highlight the need to consider postnatally acquired CMV infection in patients with PVD non-responsive to standard pulmonary vasodilator therapies or disease severity which is out of proportion of the usual clinical trajectory. Treatment of extremely premature infants with CMV-associated PVD may have positive impact on cardiorespiratory health, although duration of therapy remains uncertain.

Compassion-focused therapy (CFT) for the reduction of the self-stigma of mental disorders: the COMpassion for Psychiatric disorders, Autism and Self-Stigma (COMPASS) study protocol for a randomized controlled study

BACKGROUND

People with mental disorders face frequent stigmatizing attitudes and behaviors from others. Importantly, they can internalize such negative attitudes and thus self-stigmatize. Self-stigma is involved in diminished coping skills leading to social avoidance and difficulties in adhering to care. Reducing self-stigma and its emotional corollary, shame, is thus crucial to attenuate the negative outcomes associated with mental illness. Compassion-focused therapy (CFT) is a third-wave cognitive behavioral therapy that targets shame reduction and hostile self-to-self relationship and allows for symptom improvement while increasing self-compassion. Although shame is a prominent part of the concept of self-stigma, the efficacy of CFT has never been evaluated in individuals with high levels of self-stigma. The purpose of this study is to evaluate the efficacy and acceptability of a group-based CFT program on self-stigma, compared to a psychoeducation program for self-stigma (Ending Self-Stigma) and to treatment as usual (TAU). We hypothesize that diminished shame and emotional dysregulation and increased self-compassion will mediate the relationship between self-stigma improvements post-therapy in the experimental group.

METHODS

This seven-center trial will involve 336 participants diagnosed with a severe mental illness and/or autism spectrum disorder and reporting high levels of self-stigma. Participants will be randomized into one of three treatment arms: 12 week-treatment of compassion-focused therapy (experimental arm), 12 week-treatment of Psychoeducation (active control arm), and TAU (treatment as usual-passive control arm). The primary outcome is the decrease of self-stigma scores on a self-report scale, i.e., ISMI, at 12 weeks. Secondary endpoints include sustainability of self-stigma scores (ISMI) and self-reported scores regarding target psychological dimensions, e.g., shame and emotional regulation, social functioning, and psychiatric symptoms. Assessments are scheduled at pretreatment, post-treatment (at 12 weeks), and at 6-month follow-up. Acceptability will be evaluated via (i) the Credibility and Expectancy Questionnaire at T0, (ii) the Consumer Satisfaction Questionnaire for Psychotherapeutic Services posttreatment and at 6-month follow-up, (iii) attendance, and (iv) dropout rates.

DISCUSSION

This study will evaluate the potential efficacy and acceptability of a group-based CFT program on the decrease of self-stigma and thereby contribute to the continuing development of evidence-based therapeutic interventions for the internalized stigma of mental and neurodevelopmental disorders.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05698589. Registered on January 26, 2023.

[Anticholinergic scales: Use in psychiatry and update of the anticholinergic impregnation scale]

Anticholinergic properties are well known to prescribers, notably in mental health, as a therapeutic strategy for i.e. extrapyramidal syndrome but also as a source of numerous adverse side effects. Herein, we propose a narrative literature review describing: (i) cholinergic pharmacology and anticholinergic properties; (ii) the importance of anticholinergic therapeutic properties in psychiatry; (iii) the existing anticholinergic drug scales and their usage limitations in Psychiatry and; last (iv) an update to the anticholinergic drug impregnation scale, designed for the French psychiatry practice. The anticholinergic side effects can appear both in the peripheral level (dry mouth, constipation, etc.) and in the central level (especially as cognitive deficits). Many of the so called « anticholinergic » drugs are in fact entirely or mostly antimuscarinic and act essentially as parasympathetic system antagonists. Overall, anticholinergic/antimuscarinic side effects are usually attributed to psychotropic medications: to certain antipsychotics, notably classical neuroleptics such as phenothiazine and also to tricyclic antidepressants. In practice, the impact of anticholinergic toxicity treatments is often highlighted due to their excessively prolonged use in patients on antipsychotics. Interestingly, these antipsychotic treatments are better known for their anticholinergic side effects, especially cognitive ones, with an early onset specially in elder patients and/or in the case of polymedication. In order to evaluate anticholinergic side effects, metrics known as anticholinergic burden scales were created in the last few decades. Nowadays, 13 different scales are documented and accepted by the international academic community, but only three of them are commonly used: the Anticholinergic Drug Scale (ADS), the Anticholinergic Risk Scale (ARS) and the Anticholinergic Burden Scale (ACB). All of them are based on a similar principle, consisting of grading treatments individually, and they are normally scored from 0 - no presence of side effects - to 3 - anticholinergic effects considered to be strong or very strong. Using these scales enables the calculation of the so-called "anticholinergic burden", which corresponds to the cumulative effect of using multiple medications with anticholinergic properties simultaneously. The application of anticholinergic scales to patients with psychiatric disorders has revealed that schizophrenic patients seem to be especially sensitive to anticholinergic cognitive side effects, while elder and depressed patients were more likely to show symptoms of dementia when exposed to higher anticholinergic burden. Unfortunately, these tools appear to have a low parallel reliability, and so they might induce large differences when assessing side effects predictability. In addition, the capacity of these scales to predict central adverse effects is limited due to the fact they poorly or do not differentiate, the ability of treatments to cross the blood-brain barrier. Finally, one last limitation on the validity of these scales is prescription posology is not accounted for side effects considered to be dose dependent. Recently, the MARANTE (Muscarinic Acetylcholine Receptor ANTagonist Exposure) scale has incorporated an anticholinergic burden weighting by posology. Nevertheless, this new model can be criticized, due to the limited number of medications included and due to testing a limited number of potency ranges and dosages for each treatment. Herein, we propose an update to the Anticholinergic Impregnation Scale, developed specifically for the French Psychiatry practice. The scale validation was based on an evaluation of the prescriptions correcting anticholinergic peripheral side effects (constipation, xerostomia and xeropthalmia). This indirect evaluation allowed us to show patients with an anticholinergic impregnation score higher than 5 received significantly more treatments for constipation and xerostomia. This strategy bypasses the bias of a cognitive evaluation in patients with severe mental health disorders. Moreover, the relevance of a tool developed specifically for French psychiatry is justified by the fact that some highly prescribed treatments for mental illness in France (cyamemazine and tropatemine) are strong anticholinergics, and also by the fact they are rarely included in the existing anticholinergic scales. This update of the original scale, published in 2017, includes information whether prescribed drugs cross the blood-brain barrier and thus makes possible a more accurate assessment when evaluating anticholinergic central side effects. Finally, the anticholinergic impregnation scale will soon be integrated into a prescription help software, which is currently being developed to take into consideration dose dependent adverse effects.

Psychotropics and COVID-19: An analysis of safety and prophylaxis

The use of psychotropics during the COVID-19 pandemic has raised two questions, in order of importance: first, what changes should be made to pharmacological treatments prescribed to mental health patients? Secondly, are there any positive side effects of these substances against SARS-CoV-2? Our aim was to analyze usage safety of psychotropics during COVID-19; therefore, herein, we have studied: (i) the risk of symptomatic complications of COVID-19 associated with the use of these drugs, notably central nervous system activity depression, QTc interval enlargement and infectious and thromboembolic complications; (ii) the risk of mistaking the iatrogenic impact of psychotropics with COVID-19 symptoms, causing diagnostic error. Moreover, we provided a summary of the different information available today for these risks, categorized by mental health disorder, for the following: schizophrenia, bipolar disorder, anxiety disorder, ADHD, sleep disorders and suicidal risk. The matter of psychoactive substance use during the pandemic is also analyzed in this paper, and guideline websites and publications for psychotropic treatments in the context of COVID-19 are referenced during the text, so that changes on those guidelines and eventual interaction between psychotropics and COVID-19 treatment medication can be reported and studied. Finally, we also provide a literature review of the latest known antiviral properties of psychotropics against SARS-CoV-2 as complementary information.

[Psychopharmacotherapeutic guidelines : a challenge during health crisis]

The construction of pharmacological guidelines is a complex endeavor, and this is all the truer amidst a health crisis such as the current SARS-CoV-2 pandemic. In psychiatric settings, guidelines have to consider the handling of other drugs (i.e., psychotropic medications), that have been suggested as potentially prophylactic for COVID-19. These dialectics are discussed here, and the methodological foundations used for the elaboration of guidelines are put forward.

Panic and pandemic: Narrative review of the literature on the links and risks of panic disorder as a consequence of the SARS-CoV-2 pandemic

Although the “panic” word has been abundantly linked to the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic in the press, in the scientific literature very few studies have considered whether the current epidemic could predispose to the onset or the aggravation of panic attacks or panic disorder. Indeed, most studies thus far have focused on the risk of increase and aggravation of other psychiatric disorders as a consequence of the SARS-CoV-2 epidemic, such as obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and generalized anxiety disorder (GAD). Yet, risk of onset or aggravation of panic disorder, especially the subtype with prominent respiratory symptoms, which is characterized by a fear response conditioning to interoceptive sensations (e.g., respiratory), and hypervigilance to these interoceptive signals, could be expected in the current situation. Indeed, respiratory symptoms, such as coughs and dyspnea, are among the most commonly associated with the SARS-CoV-2 (59–82% and 31–55%, respectively), and respiratory symptoms are associated with a poor illness prognosis. Hence, given that some etiological and maintenance factors associated with panic disorder – i.e., fear conditioning to abnormal breathing patterns attributable or not to the COVID-19 (coronavirus disease 2019), as well as hypervigilance towards breathing abnormalities – are supposedly more prevalent, one could expect an increased risk of panic disorder onset or aggravation following the COVID-19 pandemic in people who were affected by the virus, but also those who were not. In people with the comorbidity (i.e., panic disorder or panic attacks and the COVID-19), it is particularly important to be aware of the risk of hypokalemia in specific at-risk situations or prescriptions. For instance, in the case of salbutamol prescription, which might be overly used in patients with anxiety disorders and COVID-19, or in patients presenting with diarrhea and vomiting. Hypokalemia is associated with an increased risk of torsade de pointe; thus, caution is required when prescribing specific psychotropic drugs, such as the antidepressants citalopram and escitalopram, which are first-line treatments for panic disorder, but also hydroxyzine, aiming at anxiety relief. The results reviewed here highlight the importance of considering and further investigating the impact of the current pandemic on the diagnosis and treatment of panic disorder (alone or comorbid with the COVID-19).

[Panic and pandemic: Review of the literature on the links between panic disorder and the SARS-CoV-2 epidemic]

L’état de panique associé à la pandémie liée au SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) incite à s’interroger sur les troubles anxieux que cette situation pourrait générer ou aggraver. Si la littérature a déjà fourni des projections généralistes en la matière, les données concrètes concernent à ce stage davantage le trouble de stress post-traumatique et le trouble obsessionnel compulsif, tandis que quelques évaluations s’intéressent au cadre nosographie du trouble anxieux généralisé. Le trouble panique ne se voit que peu ou pas cité et l’évocation de la « panique », au sens social, la supplante largement. Bien que d’une légitimité clinique encore débattue, le trouble panique qualifié de « respiratoire » pourrait se voir augmenter en nombre et/ou être intensifié chez les patients qui en présentent déjà. D’éventuelles situations co-morbides entre un tel trouble et la COVID-19 (coronavirus disease 2019) doivent inciter à certaines précautions en matière de prescriptions médicamenteuses, notamment en lien avec les traitements ou situations, sources d’hypokaliémie : (i) le salbutamol, source potentielle de surconsommation, notamment chez les patients anxieux ; (ii) l’infection par le SARS-CoV-2 et plus encore en cas de diarrhées et/ou vomissements. L’hypokaliémie est associée à un risque accru de torsade de pointe, il convient donc également d’être prudent en matière de prescription de psychotropes à risque : comme avec le citalopram et l’escitalopram, des antidépresseurs indiqués dans le trouble panique ou encore l’hydroxyzine, à visée anxiolytique. Ces données sont de nature à resituer l’importance de la prise en considération du trouble panique dans le cadre de la pandémie en cours.

Évolution des phénomènes tachypsychiques en fonction des variations de l’humeur chez deux patients cyclothymiques : données sur 14 semaines issues de l’étude PSYCHE

Introduction

Habituellement décrite dans les états maniaques chez des patients avec troubles de l’humeur, la tachypsychie est définie comme une accélération de la pensée ou « racing thoughts », car les idées se succèdent rapidement contrairement au ralentissement psychomoteur de la dépression. Toutefois, la tachypsychie peut se trouver également associée à des états dépressifs mixtes. Les patients décrivent alors une impression de tête pleine de pensées qui se bousculent, ce qui est décrit par le terme « crowded thoughts » [1]. Peu d’études se sont intéressées à la phénoménologie et à l’évaluation de la tachypsychie. Nous décrivons ici les données obtenues chez deux patients cyclothymiques - une femme et un homme - à l’échelle que nous avons élaborée, le Racing and Crowded Thoughts Questionnaire (RCTQ), dans le cadre de l’étude longitudinale PSYCHE.

Methods

Pendant 14 semaines, le RCTQ, autoquestionnaire composé de 34 items, a été proposé de façon hebdomadaire lors d’une évaluation clinique comprenant les échelles YMRS (manie) et QIDS-C16 (dépression). Des analyses de corrélations intra-sujet entre les résultats à la YMRS et le RCTQ, d’une part, et à la QIDS-C16 et le RCTQ, d’autre part, ont été réalisées.

Résultats

Chez la patiente cyclothymique, une corrélation positive et une tendance à la corrélation négative ont été observées respectivement avec les résultats de la YMRS et de la QIDS-C16. Chez le patient, seuls les résultats à la QIDS-C16 sont corrélés positivement à ceux du RCTQ.

Conclusion

Ces résultats suggèrent que la tachypsychie peut être associée à des états maniaques, mais également à des états dépressifs, notamment ceux accompagnés d’une irritabilité. Une étude de validation du RCTQ est en cours, afin d’évaluer sa structure bifactorielle (« racing » versus « crowded thoughts ») et sa spécificité vis-à-vis des phénomènes voisins, tels que la rumination.

Comment constituer, au sein de la population générale, un échantillon de sujets cyclothymiques ? Expérience à Strasbourg dans le cadre du projet PSYCHE

Contrairement au trouble cyclothymique qui est défini par une labilité affective ayant un impact fonctionnel mais d’intensité et d’une durée insuffisantes pour répondre aux critères d’épisodes thymiques [2], le tempérament cyclothymique se caractérise par les mêmes variations thymiques en l’absence de répercussions [1]. Malgré la prévalence – trouble et tempérament confondus – estimée à 0,4 et 2,5 % de la population générale [3], les études concernant la cyclothymie restent négligées. Dans une revue épidémiologique des troubles bipolaires, parmi une centaine d’études, seules huit concernent la cyclothymie [4]. Peut-on expliquer cette négligence par des difficultés de recrutement de sujets cyclothymiques ? Nous présentons, ici, notre procédure de recrutement de huit sujets avec tempérament ou trouble cyclothymique dans le contexte du projet PSYCHE. Ce projet vise à évaluer un système personnalisé et interactif permettant la surveillance et l’évaluation de variables physiologiques afin de prédire des changements d’humeur. Une annonce a été publiée sur le site Internet et Intranet des hôpitaux universitaires de Strasbourg (HUS). La version brève de la sous-échelle de cyclothymie du TEMPS-A y était proposée. Les coordonnées des sujets dont le score était supérieur ou égal à 9/12 nous étaient envoyées automatiquement. En onze jours, 95 personnes ont eu un score supérieur à 9/12. Des scores de 12, 11, 10 et 9 ont été obtenus respectivement par 19, 15, 24 et 42 % au sein de cette sous-population. Huit sujets ont été recrutés dont sept étaient des collaborateurs des HUS (à rapporter au nombre de collaborateurs en 2011:11962). Notre démarche témoigne de la rapidité et de la facilité d’accessibilité de ce type de population – notamment au sein même des HUS – pour participer à des études cliniques.

[IDEM-depression: Characteristics and evaluation of an open group that combines psychoeducation and cognitive-behavior therapy]

INTRODUCTION

Depression is a highly prevalent mental illness that is associated with high rates of morbidity and functional impairment. At the psychiatric unit of the University Hospital of Strasbourg, France, we have developed an open group that combines psychoeducation and cognitive-behavior therapy (CBT), the information, discovery, exchange and mobilization for depression group (IDEM-depression). IDEM-depression is composed of 17 thematic, structured, and independent sessions, which address different aspects of depression (i.e., rumination, pharmacological treatments). Because of its flexible format, patients with varying degrees of depression severity (from remission up to severe depressive symptoms) and whose depression might be bipolar or unipolar, are able to participate in the group. Thus, the group is well suited to a large number of patients with major depression. In the present study we aimed at describing the IDEM-depression group and presenting results regarding patients' overall satisfaction, assessed via two self-report questionnaires (the Client Satisfaction Questionnaire, the CSQ-8, and the IDEM ad hoc questionnaire), as well as its effect on mood following each session assessed via a visual analog scale (VAS) ranging from 0 up to 100.

METHOD

Sixty-five patients participated in 50 sessions of the IDEM-depression group in two hospitals in Alsace. 61% of the patients had bipolar disorder, and 41% of them were inpatients. Sessions took place on a weekly basis, lasted 2hours and were proposed by a CBT-trained clinical psychologist. Patients were asked to fill-out the VAS at the beginning and at the end of each session. Moreover, they were asked to fill-out the CSQ-8 and the IDEM ad hoc questionnaire when they left the group. Other than one session ("yoga and mindfulness"), all the sessions (16 out of 17) were structured on a Powerpoint^© presentation. During the first hour information was given regarding the topic (i.e., rumination), and a shared CBT conceptualization of the topic was formulated by the participants and the psychologist. For most sessions, the first hour was therefore communication and information-based, whereas during the second hour participants were asked to participate in in-session behavioral experiments and/or to evaluate specific aspects of their behavior (thoughts, emotions, activity, mindful behavior) during the last few days. The therapist manual and the slides for each session are available via e-mail to the first author.

RESULTS

Regarding the results, self-reported mood on the VAS was compared between the onset (225 VAS) and the end (225 VAS) of each session. Overall, results suggest that self-reported mood is significantly improved following the participation in sessions (t=-5. 87, P<0.001). Moreover, mean results on the CSQ-8 suggest that patients are highly satisfied with the group (M=24.46, SD=6.42). Among them, 82% reported a moderate-high satisfaction with the group. On the IDEM ad hoc questionnaire, patients reported an overall high satisfaction level regarding (i) the content of sessions, (ii) the duration of sessions, (iii) the frequency of sessions, (iv) how much they felt they could express themselves during sessions. In the qualitative comments of this questionnaire, patients reported that the group helped them to gain an understanding of the mechanisms involved in depression; to feel less isolated and guilty; and to learn about specific psychotherapeutic tools (i.e., mindfulness) and to try to implement them.

CONCLUSION

Our results suggest that an IDEM-depression group is well suited to a wide-array of clinical pictures associated with depression (varying severity, bipolar or unipolar, inpatients and outpatients). This is probably due to its open-group format which is particularly well-adapted to the dynamic symptomatology associated with major depression, and may stimulate decentering in patients who have different levels of severity of symptoms but participate in the same session. Moreover, its impact on mood improvement, and the high satisfaction level reported by patients, seem to be related to its CBT and psychoeducation-based content on the one hand, which has shown its efficacy in depression. On the other hand, IDEM's structured open-group format might have also contributed to the improvement in mood and the overall good satisfaction reported by patients, through the social support provided by the group, improved feeling of self-efficiency, and its effect on stigmatization. Thus, IDEM-depression group is an efficacious, flexible, low-cost, and easy to implement (in different clinical settings) psychotherapeutic option for major depression.

Spinal cord lesions and disability in Hispanics with multiple sclerosis

Longitudinally extensive spinal cord lesions (LESCLs) are believed to occur predominantly with opticospinal multiple sclerosis (OSMS) and are associated with disability. The purpose of this study is to describe the prevalence and patterns of spinal cord lesions in Hispanics with multiple sclerosis (MS) and OSMS and their association with disability. A cross-sectional study of 164 patients with complete MRIs was used. In each case the spinal cord was classified: LESCLs, scattered spinal cord lesions (sSCLs) or no spinal cord lesions (noSCLs). Clinical course was defined as classical MS or OSMS. Risk of disability (Expanded Disability Status Scale ≥4.0) was adjusted for age, disease duration and sex using logistic regression. A total of 125/164 (73 %) MS patients had spinal cord lesions (sSCLs, 57 %; LESCLs, 19 %), but only 11 (7 %) had OSMS. LESCLs were associated with disability (p < 0.0001), longer disease duration (p < 0.0001) and MS (n = 21 vs. n = 10 OSMS; p < 0.0001). LESCLs were also associated with the greatest risk to disability (OR 7.3, 95 % CIs 1.9-26.5; p = 0.003; sSCLs OR 2.5, 95 % CIs 0.9-7.1; p = 0.09) compared with noSCLs. LESCLs are more common than OSMS and are associated with worse disability even in patients with MS. These results suggest that LESCLs are a more important marker of disability in MS than OSMS and may be an early indicator of more aggressive disease in this population.

[Acute psychotic disorders related to bupropion: review of the literature]

RATIONALE AND OBJECTIVES

Bupropion, or amfebutamone, is an atypical antidepressant also used during tobacco cessation. From a structural standpoint, it resembles amphetamine drugs with psychostimulant effects, and endogenous monoamines. From a pharmacological standpoint, bupropion, and two of its most important active metabolites, inhibit dopamine and norepinephrine reuptake. It has recently been discovered that bupropion may act as a non-competitive cholinergic nicotinic receptor antagonist, and that it may inhibit the activation of reward systems triggered by nicotine. Buproprion's efficacy as a smoking cessation aid has been demonstrated by numerous clinical trials that have compared its effects with those of placebo and other nicotinic substitutes. In 2001, buproprion SR received marketing authorization in France as a smoking cessation aid, under the name ZYBAN®. Tobacco addiction indeed remains a major public health issue. Among patients with psychiatric conditions, chronic tobacco consumption is frequent. The development of non-nicotinic drugs may therefore enhance therapeutic possibilities. However, the psychotropic effects of these molecules should be taken into account. We have recently reported the case of a patient with schizoaffective disorder, who presented two acute bupropion-induced psychotic episodes. We have also undertaken an exhaustive bibliographical research on this subject. The aim of the present study is to present the information available to us, in order to suggest aetiopathogenic hypotheses and therapeutic proposals.

DATA SOURCES

The following databases were consulted on a regular basis, with no date restriction: Medline, Cochrane and Elsevier. The present study identified 22 cases of psychotic conditions associated with buproprion, as well as randomized and pharmacovigilance studies published in English, from December 1985 to November 2008. Since 2002, there have been three published case-reports on patients who underwent a tobacco cessation program.

DATA SYNTHESIS

Psychotic disorders associated with buproprion appear after an average of 10 days of 300 mg/d bupropion intake. In about two third of cases, the patients have no history of psychiatric conditions. In one third of cases, they have a history of thymic disorders. In our review, auditory, visual or cenaesthetic hallucinations frequently occur (85% of the reported cases), and are sometimes characterized by single episodes and/or are rationalized. Some of them occur along with delusional episodes (mystical, paranoid, etc.). The patients are restless, confused, but seldom exhibit dissociative and thymic symptoms.

DISCUSSION AND CONCLUSIONS

From an aetiopathogenic, clinical and evolutive standpoint, buproprion-induced psychotic episodes share many similarities with acute organic or toxic psychosis (notably induced by amphetamines). The hypothesis of a dopaminergic hyper-reactivity should be analyzed. Moreover, most of these patients were taking other medication, and the possibility of a dopaminergic potentialization prior to buproprion intake could be suggested. In such cases, bupropion should be discontinued and complete remission is expected within an average of 10 days. Even though neuroleptic drugs are still frequently used in these cases, benzodiazepines could become a valid alternative, according to the model of amphetamine-induced acute psychosis.

The antidiabetic effect and pharmacokinetic properties of glipizide. Comparison of a single dose with divided dose regime

In 13 patients with maturity-onset diabetes mellitus which did not respond to diet therapy alone, serum concentration of glipizide, blood glucose (B-G) concentration, serum immunoreactive insulin (S-IRI) and plasma glycerol (P-G) were monitored hourly over 12 hours after placebo, an initial dose of glipizide (5 mg p.o.) and long-term treatment with glipizide (range 7.5--20 mg, mean 10.4), which produced fasting B-G of less than 8 mmol/l. During the long-term treatment, glipizide was given in a random, cross-over pattern, either as a single dose in the morning or as a three-part divided dose regime, in the same total daily amount. The duration of the immediate effects of glipizide on B-G, S-IRI and S-IRI/B-G was 9, 4.5 and 6.5 hours, respectively. The mean apparent half-life of glipizide was 4.1 hours, the mean distribution volume 0.13 l/kg and the mean plasma clearance 0.023 l/kg x h. The area under the concentration curve from 7.30 a.m. to 7.30 p.m. was 15% higher after the single dose regime. The serum levels of glipizide at 10 hours were only 30% lower than after the three-part divided dose regime. There were no significant differences between the single and divided dose regimes as regards B-G, S-IRI and S-IRI/B-G, although the mean B-G for the 12-hour period was somewhat lower after the former than after the latter (7.0 against 8.7 mmol/l).

Phase 1 trial of the antiangiogenic peptide ATN-161 (Ac-PHSCN-NH(2)), a beta integrin antagonist, in patients with solid tumours

To evaluate the toxicity, pharmacological and biological properties of ATN-161, a five –amino-acid peptide derived from the synergy region of fibronectin, adult patients with advanced solid tumours were enrolled in eight sequential dose cohorts (0.1–16 mg kg⁻¹), receiving ATN-161 administered as a 10-min infusion thrice weekly. Pharmacokinetic sampling of blood and urine over 7 h was performed on Day 1. Twenty-six patients received from 1 to 14 4-week cycles of treatment. The total number of cycles administered to all patients was 86, without dose-limiting toxicities. At dose levels above 0.5 mg kg⁻¹, mean total clearance and volume of distribution showed dose-independent pharmacokinetics (PKs). At 8.0 and 16.0 mg kg⁻¹, clearance of ATN-161 was reduced, suggesting saturable PKs. Dose escalation was halted at 16 mg kg⁻¹ when drug exposure (area under the curve) exceeded that associated with efficacy in animal models. There were no objective responses. Six patients received more than four cycles of treatment (>112 days). Three patients received 10 or more cycles (⩾280 days). ATN-161 was well tolerated at all dose levels. Approximately, 1/3 of the patients in the study manifested prolonged stable disease. These findings suggest that ATN-161 should be investigated further as an antiangiogenic and antimetastatic cancer agent alone or with chemotherapy.

High affinity promotes more effective ADCC by anti-HER2/neu monoclonal antibodies

2538

Background: Although monoclonal antibodies have emerged as useful cancer therapeutics, the antibody structural features and biologic properties that maximize therapeutic benefit are not fully understood. Antibody-dependent cellular cytotoxicity (ADCC) is believed to be a major mechanism of some anti-cancer antibodies. Herein, we describe the relationship between antibody affinity and the biologic properties of ADCC. Methods: A series of human IgG1 antibodies was created from the anti-HER2/neu C6.5 scFv and its affinity mutants (affinity ranging from 10−7 to 10−11 M). The IgGs were tested for their ability to elicit ADCC using a standard 51Cr-release assay. The ability of these IgGs to inhibit tumor cell proliferation and to induce apoptosis was evaluated using a colorimetric cell proliferation assay and homogeneous caspase assay/Annexin-V-FLUOS assay, respectively. Three tumor cell lines with differing levels of HER2/neu expression were used as target cells, and unactivated human PBMC from healthy donors were the effector cells. Results: There was a clear influence of both intrinsic and functional affinity on ADCC, with higher levels of peak cytotoxicity as apparent affinity approached 10−11 M. Among the antibodies with apparent affinity of 10−11 M, antibodies with higher intrinsic affinities elicited more ADCC. There also was an affinity-dependent increase in cytotoxicity at lower antibody concentrations and lower effector: target ratios. These antibodies elicited more cytotoxicity against tumor cells expressing high levels of HER2/neu than against cells expressing lower amounts of HER2/neu. None of these IgGs inhibited tumor cell proliferation, or induced apoptosis. Conclusions: Additional studies are needed to determine why, at the same functional avidity, ADCC is improved in antibodies with higher intrinsic affinities. These findings justify the examination of high affinity antibodies for ADCC promotion, although the impaired tumor targeting associated with high affinity may be an important confounding factor in the design of unconjugated anti-tumor antibodies. A careful examination of antibody structure: function relationships is required to develop optimized therapeutic unconjugated antibodies.

No significant financial relationships to disclose.

Delta9-tetrahydrocannabinol increases C6 glioma cell death produced by oxidative stress

(-)Delta9-tetrahydrocannabinol is a scavenger of free radicals. However, the activation of the CB1 receptor in cultured C6 glioma cells by (-)delta9-tetrahydrocannabinol in the presence of reagents generating reactive oxygen species leads to amplification of the cellular damage from oxidative stress. This was evident by increased loss of cell wall integrity, impaired mitochondrial function and reduction of glucose uptake. In addition, (-)delta9-tetrahydrocannabinol treatment was also found to be deleterious to the cells under conditions of glucose starvation. Free radicals have been implicated in various conditions leading to cell death and, as a routine, the Fenton reaction is utilized for modeling reactive oxygen species production. Our study was performed using a cell permeating Fe(III) chelating quinone that provides more physiological conditions for mimicking the naturally occurring oxidative stress within the cell and thus serves as a better model for natural reactive oxygen species formation.

Thermal denaturation of Bungarus fasciatus acetylcholinesterase: Is aggregation a driving force in protein unfolding?

A monomeric form of acetylcholinesterase from the venom of Bungarus fasciatus is converted to a partially unfolded molten globule species by thermal inactivation, and subsequently aggregates rapidly. To separate the kinetics of unfolding from those of aggregation, single molecules of the monomeric enzyme were encapsulated in reverse micelles of Brij 30 in 2,2,4-trimethylpentane, or in large unilamellar vesicles of egg lecithin/cholesterol at various protein/micelle (vesicle) ratios. The first-order rate constant for thermal inactivation at 45 degrees C, of single molecules entrapped within the reverse micelles (0.031 min(-1)), was higher than in aqueous solution (0.007 min(-1)) or in the presence of normal micelles (0.020 min(-1)). This clearly shows that aggregation does not provide the driving force for thermal inactivation of BfAChE. Within the large unilamellar vesicles, at average protein/vesicle ratios of 1:1 and 10:1, the first-order rate constants for thermal inactivation of the encapsulated monomeric acetylcholinesterase, at 53 degrees C, were 0.317 and 0.342 min(-1), respectively. A crosslinking technique, utilizing the photosensitive probe, hypericin, showed that thermal denaturation produces a distribution of species ranging from dimers through to large aggregates. Consequently, at a protein/vesicle ratio of 10:1, aggregation can occur upon thermal denaturation. Thus, these experiments also demonstrate that aggregation does not drive the thermal unfolding of Bungarus fasciatus acetylcholinesterase. Our experimental approach also permitted monitoring of recovery of enzymic activity after thermal denaturation in the absence of a competing aggregation process. Whereas no detectable recovery of enzymic activity could be observed in aqueous solution, up to 23% activity could be obtained for enzyme sequestered in the reverse micelles.

Evaluation of the bioequivalence of tablets and capsules containing the novel anticancer agent R115777 (Zarnestra) in patients with advanced solid tumors

R115777 (Zamestra) is a novel anticancer agent, currently undergoing phase III clinical testing. An open, cross-over trial was performed in 24 patients with solid tumors to compare the bioavailability of a new tablet formulation with the standard capsule formulation. Both dosage forms were administered once daily in doses of 300 or 400 mg. Patients received R115777 as a capsule on day I and as a tablet on day 2, or vice versa. Blood samples were drawn up to 24 hours after drug intake and R115777 levels were measured using a validated high performance liquid chromatography (HPLC) method. The following pharmacokinetic parameters were determined and compared for the two formulations: time to maximal plasma concentration (Tmax), half-life (t 1/2), maximal plasma concentration (Cmax) and area under the curve at twenty-four hours (AUC24h). For the latter two parameters, 90% classical confidence intervals of the ratio tablet/capsule were calculated after a log-transformation, using an Analysis of Variance (ANOVA). For t 1/2 and Tmax, no statistically significant differences were found between tablet and capsule. The point estimates of the ratio's of the log-normalized Cmax and AUC24h were 0.94 and 0.92, respectively, and the 90% confidence intervals were 0.81-1.09 and 0.83-1.03, which is within the critical range for bioequivalence of 0.80-1.25. In conclusion, the established pharmacokinetic parameters demonstrate that the capsule and tablet formulations of R115777 are interchangeable.

Electron and oxygen transfer in polyoxometalate, H(5)PV(2)Mo(10)O(40), catalyzed oxidation of aromatic and alkyl aromatic compounds: evidence for aerobic Mars-van Krevelen-type reactions in the liquid homogeneous phase

The mechanism of aerobic oxidation of aromatic and alkyl aromatic compounds using anthracene and xanthene, respectively, as a model compound was investigated using a phosphovanadomolybdate polyoxometalate, H(5)PV(2)Mo(10)O(40), as catalyst under mild, liquid-phase conditions. The polyoxometalate is a soluble analogue of insoluble mixed-metal oxides often used for high-temperature gas-phase heterogeneous oxidation which proceed by a Mars-van Krevelen mechanism. The general purpose of the present investigation was to prove that a Mars-van Krevelen mechanism is possible also in liquid-phase, homogeneous oxidation reactions. First, the oxygen transfer from H(5)PV(2)Mo(10)O(40) to the hydrocarbons was studied using various techniques to show that commonly observed liquid-phase oxidation mechanisms, autoxidation, and oxidative nucleophilic substitution were not occurring in this case. Techniques used included (a) use of (18)O-labeled molecular oxygen, polyoxometalate, and water; (b) carrying out reactions under anaerobic conditions; (c) performing the reaction with an alternative nucleophile (acetate) or under anhydrous conditions; and (d) determination of the reaction stoichiometry. All of the experiments pointed against autoxidation and oxidative nucleophilic substitution and toward a Mars-van Krevelen mechanism. Second, the mode of activation of the hydrocarbon was determined to be by electron transfer, as opposed to hydrogen atom transfer from the hydrocarbon to the polyoxometalate. Kinetic studies showed that an outer-sphere electron transfer was probable with formation of a donor-acceptor complex. Further studies enabled the isolation and observation of intermediates by ESR and NMR spectroscopy. For anthracene, the immediate result of electron transfer, that is formation of an anthracene radical cation and reduced polyoxometalate, was observed by ESR spectroscopy. The ESR spectrum, together with kinetics experiments, including kinetic isotope experiments and (1)H NMR, support a Mars-van Krevelen mechanism in which the rate-determining step is the oxygen-transfer reaction between the polyoxometalate and the intermediate radical cation. Anthraquinone is the only observable reaction product. For xanthene, the radical cation could not be observed. Instead, the initial radical cation undergoes fast additional proton and electron transfer (or hydrogen atom transfer) to yield a stable benzylic cation observable by (1)H NMR. Again, kinetics experiments support the notion of an oxygen-transfer rate-determining step between the xanthenyl cation and the polyoxometalate, with formation of xanthen-9-one as the only product. Schemes summarizing the proposed reaction mechanisms are presented.

Generation of free radicals by emodic acid and its [D-Lys6]GnRH-conjugate

In an attempt to develop an efficient chemotherapeutic agent targeted at malignant cells that express receptors to gonadotropin releasing hormone (GnRH) we coupled [D-Lys6]GnRH covalently to an emodin derivative, i.e. emodic acid (Emo) to yield [D-Lys6(Emo)]GnRH. Emodin is a naturally occurring anthraquinone which is widely used as a laxative and has other versatile biological activities. Physico-chemical studies employing electron paramagnetic resonance and electrochemistry of the conjugate as well as the (Emo) moiety showed that these compounds could be easily reduced either chemically, photochemically or enzymatically to their corresponding semiquinones. In the presence of oxygen the semiquinones generated reactive oxygen species (ROS), mainly superoxide and hydroxyl radicals, which were detected by the spin trapping method. Moreover, upon irradiation with visible light these compounds produced ROS and a highly reactive excited triplet state of Emo, which by itself may cause the oxidation of certain electron acceptors such as amino acids and bases of nucleic acids. Thus, [D-Lys6]GnRH-photosensitizer conjugates may be potentially used for targeted photodynamic chemotherapy aimed at treating cancer cells that carry GnRH receptors. These conjugates may also induce cytotoxicity in the dark similar to common conventional chemotherapeutic agents. The peptidic moiety, [D-Lys6]GnRH, was found to be stable toward highly reactive ROS generated either from enzymatic reduction or upon photoirradiation. The physico-chemical properties of Emo were only marginally influenced by the peptidic [D-Lys6]GnRH carrier.

Hypericin derivatives: substituent effects on radical-anion formation

The electron-transfer properties of the hypericin derivatives, dibromo-, hexaacetyl-, hexamethyl- and desmethylhypericin, were studied. Cyclovoltammetric measurements revealed that dibromo- and desmethylhypericin have almost the same redox potentials as the parent hypericin. Substitution of the hydroxyl groups by acetoxy leads to less negative E1/2 values, whereas methoxy substitution induces more negative values. Electron paramagnetic resonance (EPR)/electron nuclear double resonance/general TRIPLE spectroscopy and quantum mechanical calculations were used to establish the structure of the one-electron reduced stages of hypericin derivatives. Proton loss in the bay region, already demonstrated for hypericin, was also found for dibromo- and desmethylhypericin. The spin and charge of the radical ions are predominately confined to the central biphenoquinone moiety of the hypericin skeleton. Generation of the radical ions by in situ electrolysis indicates that the redox potentials of hypericin, dibromo- and desmethylhypericin, containing hydroxyls at the 1, 3, 4, 6, 8 and 13 positions, largely depend on the solvent. With phosphate-buffered saline (pH 7.4)/dimethylsulfoxide (DMSO) as the solvent the EPR spectra of the corresponding radical ions appear at markedly lower potentials than in pure DMSO and N,N'-dimethylformamide. However, this effect is not observable for hexaacetyl- and hexamethyl-hypericin-lacking hydroxyl groups. In all cases the EPR data and calculations revealed the presence of 7,14 tautomers.

Specific binding sites for cations in bacteriorhodopsin

The Asp-85 residue, located in the vicinity of the retinal chromophore, plays a key role in the function of bacteriorhodopsin (bR) as a light-driven proton pump. In the unphotolyzed pigment the protonation of Asp-85 is responsible for the transition from the purple form (lambda(max) = 570 nm) to the blue form (lambda(max) = 605 nm) of bR. This transition can also be induced by deionization (cation removal). It was previously proposed that the cations bind to the bR surface and raise the surface pH, or bind to a specific site in the protein, probably in the retinal vicinity. We have reexamined these possibilities by evaluating the interaction between Mn(2+) and a nitroxyl radical probe covalently bound to several mutants in which protein residues were substituted by cystein. We have found that Mn(2+), which binds to the highest-affinity binding site, significantly affects the EPR spectrum of a spin label attached to residue 74C. Therefore, it is concluded that the highest-affinity binding site is located in the extracellular side of the protein and its distance from the spin label at 74C is estimated to be approximately 9.8 +/- 0.7 A. At least part of the three to four low-affinity cation binding sites are located in the cytoplasmic side, because Mn(2+) bound to these binding sites affects spin labels attached to residues 103C and 163C located in the cytoplasmic side of the protein. The results indicate specific binding sites for the color-controlling cations, and suggest that the binding sites involve negatively charged lipids located on the exterior of the bR trimer structure.

Nonisomerizable non-retinal chromophores initiate light-induced conformational alterations in bacterioopsin

The photoactivation of retinal proteins is usually interpreted in terms of C=C photoisomerization of the retinal moiety, which triggers appropriate conformational changes in the protein. In this work several dye molecules, characterized by a completely rigid structure in which no double-bond isomerization is possible, were incorporated into the binding site of bacteriorhodopsin (bR). Using a light-induced chemical reaction of a labeled EPR probe, it was observed that specific conformational alterations in the protein are induced following light absorption by the dye molecules occupying the binding site. The exact nature of these changes and their relationship to those occurring in the bR photocycle are still unclear. Nevertheless, their occurrence proves that C=C or C=NH(+) isomerization is not a prerequisite for protein conformational changes in a retinal protein. More generally, we show that conformational changes, leading to changes in reactivity, may be induced in proteins by optical excitation of simple nonisomerizable dyes located in the macromolecular matrix.

Enhanced free radical scavenging and decreased lipid peroxidation in the rat fetal brain after treatment with ethyl docosahexaenoate

In order to explore possible mechanisms to explain previously observed decreases in fetal brain lipid peroxidation (LPO) following intraamniotic administration of ethyl docosahexaenoate (Et-DHA) to near term fetuses, the hydroxyl radical trapping capacity of Et-DHA treated fetal brain preparations was compared to control ethyl oleate injected fetuses by electron spin resonance using 5,5'-dimethyl-1-pyrroline N-oxide (DMPO) probe. Lipid extracts from control brains showed little hydroxyl radical scavenging activity, whereas those from the Et-DHA injected animals exhibited an almost 70% decrease in the amount of DMPO-OH adducts. A marked decrease (58%) in LPO formation was noticed in the Et-DHA treated animals compared to controls. The Et-DHA treatment related trapping capacity resided in the phospholipid fraction of the lipid extract, which was enriched in both docosahexaenoic acid and aminophospholipid contents. The decreased LPO production, as well as increased production of prostaglandin E(2) and nitric oxide by the fetal brain following Et-DHA administration, could be mimicked by a synthetic quinone possessing both hydroxyl radical producing and LPO propagation inhibiting properties. The data are consistent with the possibility that the neuroprotective effect of Et-DHA might be due to possible free radical scavenging ability of the brain tissue and interference with LPO propagation.

S-Allylmercaptoglutathione: the reaction product of allicin with glutathione possesses SH-modifying and antioxidant properties

The reaction between allicin (diallylthiosulfinate), the active component of garlic and reduced glutathione was investigated. The product of this reaction, mixed disulfide S-allylmercaptoglutathione (GSSA) was separated by high performance liquid chromatography and identified by 1H and (13)C nuclear magnetic resonance and mass spectroscopy. The reaction is fast (with an apparent bimolecular reaction rate constant of 3.0 M(-1) s(-1)). It is pH-dependent, which reveals a direct correlation to the actual concentration of mercaptide ion (GS(-)). Both GSSA and S-allylmercaptocysteine (prepared from allicin and cysteine) reacted with SH-containing enzymes, papain and alcohol dehydrogenase from Thermoanaerobium brockii yielding the corresponding S-allylmercapto proteins, and caused inactivation of the enzymes. The activity was restored with dithiothreitol or 2-mercaptoethanol. In addition, GSSA also exhibited high antioxidant properties. It showed significant inhibition of the reaction between OH radicals and the spin trap 5,5'-dimethyl-1-pyroline N-oxide in the Fenton system as well as in the UV photolysis of H2O2. In ex vivo experiments done with fetal brain slices under iron-induced oxidative stress, GSSA significantly lowered the production levels of lipid peroxides. The similar activity of GSSA and allicin as SH-modifiers and antioxidants suggests that the thioallyl moiety has a key role in the biological activity of allicin and its derivatives.

Bacteriorhodpsin experiences light-induced conformational alterations in nonisomerizable C(13)=C(14) pigments. A study with EPR

The mechanism by which bacteriorhodopsin is activated following light absorption is not completely clear. We have detected protein conformational alterations following light absorption by retinal-based chromophores in the bacteriorhodopsin binding site by monitoring the rate of reduction-oxidation reactions of covalently attached spin labels, using EPR spectroscopy. It was found that the reduction reaction with hydroxylamine is light-catalyzed in the A103C-labeled pigment but not in E74C or M163C. The reaction is light-catalyzed even when isomerization of the C(13)=C(14) bond of the retinal chromophore is prevented. The reverse oxidation reaction with molecular oxygen is effective only in apomembrane derived from the mutant A103C. This reaction is light-accelerated following light absorption of the retinal oxime, which occupies the binding site. The light-induced acceleration is evident also in "locked" bacteriorhodopsin in which isomerization around the C(13)=C(14) bond is prevented. It is evident that the chromophore-protein covalent bond is not a prerequisite for protein response. In contrast to the case of the retinal oxime, a reduced C=N bond A103C-labeled pigment did not exhibit acceleration of the oxidation reaction following light absorption. Acceleration was observed, however, following substitution of the polyene by groups that modify the excited state charge delocalization. It is suggested that protein conformational alterations are induced by charge redistribution along the retinal polyene following light absorption.

Alternative subcellular locations of keratinocyte basonuclin

Basonuclin is a zinc finger protein present in the basal cell layer of the epidermis and in hair follicles. Human basal epidermal cells are often heterogeneous with respect to a nuclear or cytoplasmic location of basonuclin and the protein may be concentrated in either compartment. In mouse and rat epidermis, although clusters of basonuclin may be seen in some basal cell nuclei, the protein is mainly concentrated in the cytoplasm. When epidermis whose basal cells contain predominantly cytoplasmic basonuclin is disaggregated and the cells are cultivated in the presence of supporting 3T3 cells, the basonuclin of the growing keratinocyte colonies is strongly concentrated in the cell nuclei. Transfer of the cells to culture medium without supporting 3T3 cells results in a predominantly cytoplasmic concentration of the basonuclin. This translocation is reversible, since addition of supporting 3T3 cells restores most basonuclin to the nucleus. The nuclear location is associated with more rapid cell growth. We conclude that different states of the keratinocyte require greater or less activity of basonuclin, and the subcellular location of the protein is probably related to the magnitude of its action on the cells.

The mode of action of allicin: its ready permeability through phospholipid membranes may contribute to its biological activity

Allicin (diallyl thiosulfinate) is the main biologically active component of the freshly crushed garlic extracts. In the present work the ability of allicin to cross through membranes (artificial and biological) was studied. Partition coefficients of allicin in water/octanol, water/hexadecane and water/phospholipids mixtures were determined. Using phospholipid vesicles loaded with hydrophilic thiols (reduced glutathione or 2-nitro-5-thiobenzoate), we observed that allicin freely permeates through phospholipid bilayers and interacts with the SH groups. The reaction rate of allicin with SH containing molecules after crossing the membrane was the same as in solution. Fast diffusion and permeation of allicin across human red blood cell membranes was also demonstrated. Allicin does not induce leakage, fusion or aggregation of membrane. The high permeability of allicin through membranes may greatly enhance the intracellular interaction with thiols.

Targeted cross-linking of a molten globule form of acetylcholinesterase by the virucidal agent hypericin

The natural product hypericin is a photosensitive polycyclic aromatic dione compound, which has been widely investigated because of its virucidal and antitumor properties. Although it has been suggested that singlet oxygen or a radical species might be responsible for its biological action, its mechanism of action remains unknown. Due to its amphiphilic characteristics, we considered the possibility that it might interact preferentially with partially unfolded proteins which exhibit exposed hydrophobic surfaces. We here demonstrate that hypericin binds to a molten globule species generated from Torpedo acetylcholinesterase, but not to the corresponding native enzyme. Irradiation with visible light, under aerobic conditions, causes chemical cross-linking of the catalytic subunits, to dimers and heavier species, under conditions where no cross-linking is observed for the native enzyme. Both anaerobiosis and sodium azide greatly reduce the extent of cross-linking, suggesting that singlet oxygen is responsible for the phenomenon. This agrees with our observation, using spin traps, that mainly singlet oxygen is produced by the complex of hypericin with the molten globule of acetylcholinesterase. Cross-linking is enhanced in the presence of liposomes to which the molten globule of acetylcholinesterase is quantitatively adsorbed. This may be due to high local concentrations of both hypericin and the protein resulting in close proximity, and hence in a high yield of cross-linking. Molten globule species are believed to be intermediates in both protein folding and translocation through biological membranes. Thus, hypericin may serve as a valuable tool for trapping such intermediates. This might also explain its therapeutic effectiveness toward virus-infected or tumor cells.

Ectopic expression of the nude gene induces hyperproliferation and defects in differentiation: implications for the self-renewal of cutaneous epithelia

Nude mice are characterized by the absence of visible hair, epidermal defects, and the failure to develop a thymus. This phenotype results from loss-of-function mutations in Whn (Hfh11), a winged-helix transcription factor. In murine epidermis and hair follicles, endogenous whn expression is induced as epithelial cells initiate terminal differentiation. Using the promoter for the differentiation marker involucrin, transgenic mice that ectopically express whn in stratified squamous epithelia, hair follicles, and the transitional epithelium of the urinary tract were generated. Transgenic epidermis and hair follicles displayed impaired terminal differentiation and a subset of hair defects, such as delayed growth, a waved coat, and curly whiskers, correlated with decreased transforming growth factor (TGF)-alpha expression. The exogenous Whn protein also stimulated epithelial cell multiplication. In the epidermis, basal keratinocytes exhibited hyperproliferation, though transgene expression was restricted to suprabasal, postmitotic cells. Hair follicles failed to enter telogen (a resting period) and remained continuously in an abnormal anagen (the growth phase of the hair cycle). Ureter epithelium developed severe hyperplasia, leading to the obstruction of urine outflow and death from hydronephrosis. Though an immune infiltrate was present occasionally in transgenic skin, the infiltrate was not the primary cause of the epithelial hyperproliferation, as the immune reaction was not observed in all affected transgenics, and the transgene induced identical skin and urinary tract abnormalities in immunodeficient Rag1-null mice. Given the effects of the transgene on cell proliferation and TGFalpha expression, the results suggest that Whn modulates growth factor production by differentiating epithelial cells, thereby regulating the balance between proliferative and postmitotic populations in self-renewing epithelia.

A phase II study of 5-fluorouracil, leucovorin, and interferon-alpha in the treatment of patients with metastatic or recurrent gastric carcinoma: an Eastern Cooperative Oncology Group study (E5292)

BACKGROUND

Chemotherapy has a limited impact on adenocarcinoma of the stomach. Although biochemical modulation of 5-fluorouracil (5-FU) by leucovorin (LV) and interferon-alpha (IFN-alpha) has improved the outcomes of patients with metastatic colorectal carcinoma compared with 5-FU alone, this approach has not been extensively evaluated in the treatment of advanced gastric carcinoma.

METHODS

Twenty-seven patients with bidimensionally measurable, metastatic gastric carcinoma and an Eastern Cooperative Oncology Group performance status of 0 or 1 received the combination of IFN-alpha (5 million U/m2 administered subcutaneously daily on Days 1-7), LV (500 mg/m2 administered intravenously over 30 minutes immediately after IFN-alpha on Days 2-6), and 5-FU (370 mg/m2 given as an intravenous bolus 60 minutes after LV on Days 2-6), with treatment repeated every 4 weeks. Oral cryotherapy was administered routinely before each dose of 5-FU to reduce the incidence of severe stomatitis.

RESULTS

The median age of the patients was 58 years (range, 20-76), and 22 patients had residual, unresectable primary lesions. The median number of cycles received was 3 (range, 1-11). Of 24 patients who received at least 2 cycles of treatment, 15 (62.5%) did not require dose reduction for toxicity during the initial 2 cycles. The predominant toxicities were gastrointestinal: diarrhea and stomatitis of Grade 3-4 occurred in 28.6% and 35.7% of patients, respectively. Other severe (Grade 3-4) toxicities were granulocytopenia (which occurred in 21.4% of patients) and fatigue (in 10.7%). Fever and flu-like symptoms were common but usually mild. Of 24 patients who were evaluable for response, 3 had partial responses (PR) of 16, 23, and 33 weeks' duration, respectively, for a response rate of 12.5% (95% confidence interval = 2.7-32.4%). Two additional patients had reductions in tumor size sufficient for PR, but scans to document the minimum required response duration of 4 weeks were not obtained before progressive disease occurred. The median progression-free and overall survivals were 2.5 and 7.8 months, respectively.

CONCLUSIONS

Although this regimen can be administered safely with appropriate supportive care to patients with good performance status, it has limited therapeutic activity in patients with advanced gastric carcinoma.

A spectrophotometric assay for allicin and alliinase (Alliin lyase) activity: reaction of 2-nitro-5-thiobenzoate with thiosulfinates

Allicin (diallylthiosulfinate) is the main biologically active component of freshly crushed garlic cloves. It is produced upon the interaction of the nonprotein amino acid alliin with the enzyme alliinase (alliin lyase, EC 4.4.1.4). A simple and rapid spectrophotometric procedure for determination of allicin and alliinase activity, based on the reaction between 2-nitro-5-thiobenzoate (NTB) and allicin, is described. NTB reacts with the activated disulfide bond --S(O)-S--; of allicin, forming the mixed-disulfide allylmercapto-NTB, as characterized by NMR. The method can be used for determination of allicin and total thiosulfinates in garlic preparations and garlic-derived products. The method was applied for determination of pure alliinase activity and for the activity of the enzyme in crude garlic extracts.

Basonuclin as a cell marker in the formation and cycling of the murine hair follicle

Basonuclin, a zinc-finger protein, is found in stratified squamous epithelia and hair follicles. In the basal keratinocytes of mouse epidermis, basonuclin is detected mainly in the cytoplasm. During the development of murine hair follicles, this protein concentrates in the nuclei of the basal cells that form the primary hair germs. As follicle morphogenesis proceeds, the epithelial cells possessing nuclear basonuclin invade the dermis and surround the follicular papilla. In mature anagen follicles, nuclear basonuclin is principally restricted to the basal layers of the outer root sheath and bulbar matrix; these regions are known to contain cells capable of proliferation, and to lack the features of terminal differentiation. During catagen, the compartment of cells containing nuclear basonuclin regresses, and in telogen, only a small number of these cells remain to form the secondary hair germ at the follicle base. During the next anagen, this basonuclin-containing population expands and regenerates the hair-producing portion of the follicle. It is concluded that in all hair cycles, the transient segment of the follicle originates from germinative cells possessing nuclear basonuclin.

Liposome-catalyzed unfolding of acetylcholinesterase from Bungarus fasciatus

The kinetics of thermal inactivation of acetylcholinesterase from the venom of the snake, Bungarus fasciatus, were studied at 45-54 degrees C. An Arrhenius plot reveals an activation energy of 113 kcal/mol. The thermally denatured enzyme displays the spectroscopic characteristics of a partially unfolded 'molten globule' state. The rate of thermal denaturation is greatly enhanced in the presence of unilamellar vesicles of dimyristoylphosphatidylcholine, the energy barrier for the transition being lowered from 113 to 52 kcal/mol. In contrast to our findings for partially unfolded Torpedo californica acetylcholinesterase [Shin et al. (1997) Proc. Natl. Acad. Sci. U.S.A. 94, 2848-2852], the thermally denatured snake enzyme does not remain bound to the liposomes but is released after unfolding and subsequently aggregates. The liposomes thus serve as catalysts for unfolding of the snake enzyme, and its rate of unfolding in the presence of liposomes can be described by the Michaelis-Menten equation (Km = 8 x 10(-7) M). The phospholipid vesicles display a catalytic turnover number of kcat approximately 4 min-1, assuming 15 binding sites per vesicle for the snake acetylcholinesterase.

The mode of action of allicin: trapping of radicals and interaction with thiol containing proteins

Allicin (thio-2-propene-1-sulfinic acid S-allyl ester) is the main biologically active component of garlic clove extracts. Its biological activity was attributed to either antioxidant activity or thiol disulfide exchange. Antioxidant properties of both allicin and its precursor, alliin (+S-allyl-L-cysteine sulfoxide), were investigated in the Fenton oxygen-radical generating system [H2O2-Fe(II)]. Using the spin trapping technique and ESR, it was found that both compounds possessed significant antioxidant activity. The reaction between allicin and L-cysteine was studied by 1H and 13C-NMR, and a S-thiolation product, S-allylmercaptocysteine, was identified. Allicin irreversibly inhibited SH-protease papain, NADP(+)-dependent alcohol dehydrogenase from Thermoanaerobium brockii (TBAD), and the NAD(+)-dependent alcohol dehydrogenase from horse liver (HLAD). All the three enzymes could be reactivated with thiol containing compounds. Papain could be reactivated with glutathione, TBAD with dithiothreitol or 2-mercaptoethanol (2-ME) but not by glutathione, while HLAD could be reactivated only with 2-ME. This study demonstrates that in addition to its antioxidant activity, the major biological effect of allicin should be attributed to its rapid reaction with thiol containing proteins.

Vertical transmission of HIV in New York State: a basis for statewide testing of newborns

Infants (n = 313) of HIV-infected mothers were enrolled (mean age 1.9 weeks, range 0-8 weeks) in a 3-year prospective study of vertical transmission. Fifty-six infants (17.9%) had laboratory and clinical evidence of HIV infection. Polymerase chain reaction (PCR) provided early and reliable identification of infected infants. Thirty-one of the 56 infected infants had specimens submitted when the infants were 4 weeks of age or less and 30 (97%) tested PCR positive. This percentage increased to 100% by 8 weeks of age when 51 of the 56 infected infants had specimens tested for that time period. Immune complex dissociation (ICD) antigen testing was a sensitive method for diagnosis of infection but only in infants older than 1 month. p24 antigen testing, although free of false positives, is less sensitive than either of the other methods. Among surrogate markers of HIV infection, elevation of soluble CD8 levels precedes an increase in immunoglobulin levels or a decline in CD4 T lymphocytes. Vertical transmission is significantly lower in Central and Western New York State than other regions. Transmission is significantly higher in low birthweight babies and in infants whose mothers have CD4 counts < 500. This study provided the basis for establishing a Pediatric HIV PCR Testing Service for the early diagnosis of HIV infection in neonates.