Persisting consequences of drug intake: towards a memory of addiction

Long-term intake of a psychoactive drug alters brain signal transduction, emotional and motivational factors and behavioral parameters. Some effects that outlast long periods of abstinence are due to the long-term presence of the drug in the organism (tolerance, physical dependence). Withdrawal symptoms, as a consequence of physical dependence, can be protracted, i.e. they persist after long periods of drug deprivation (e.g. a desensitization of the production of cAMP). Further persisting effects include experience-based learning. At least three distinct processes can be differentiated: a memory of drug effects (reflected by a sensitization to drug effects etc.), a memory of drug use (reflected by controlled drug consumption), and a memory of addiction (reflected by a persisting loss of control over drug intake and correlating changes in striatal dopaminergic neurotransmission). The latter probably consists of two components: a general memory of loss of control and a specific memory of the addictive drug (general principles for the development of addiction, specific of the urge for the addictive drug).

The breadth of bioethics: core areas of bioethics education for hospital ethics committees

The multidisciplinary nature of bioethics can result in narrow "sub-specialists" within the field, whose work reflects the issues and concerns most relevant to their "home discipline." This can result in work which is insensitive to the important ways in which particular areas of bioethics are interrelated, and which (while viable in the context of the sub-specialty) is not viable in a broader context. The narrow focus of many healthcare ethics committees on issues directly related to clinical patient care can exacerbate this problem. Increasingly, issues in the clinical care of patients cannot be separated from issues in research, organizational ethics, and public policy. I argue that these problems call for a need to identify "core" areas for bioethics education. This is especially true for education of hospital ethics committees, which increasingly face complex cases involving concerns that fall outside traditional patient care issues. I then consider nine areas examined in detail in A Companion to Bioethics edited by Helga Kuhse and Peter Singer, as potential candidates for "core" areas of bioethics education. At the same time, I evaluate the range of issues examined in each area of the book, in the context of the book's ability to provide an introduction to each area.

The VIRGO study: nevirapine, didanosine and stavudine combination therapy in antiretroviral-naive HIV-1-infected adults

The virological and immunological efficacy of the triple regimen containing nevirapine (once or twice daily), didanosine (once daily) and stavudine, in antiretroviral-naive patients infected with HIV-1, was evaluated in an open-label, prospective, non-randomized, multi-centre, 52-week study. The first 60 patients (VIRGO I) received nevirapine as the standard dose, 200 mg twice daily; the subsequent 40 patients (VIRGO II) received nevirapine at a dose of 400 mg once daily. All patients received 400 mg of didanosine once daily and 40 mg of stavudine twice daily, adjusted for body weight. At baseline, the median CD4 cell count and plasma viral load (pVL) were 414 cells/mm3 and 4.59 log10 copies/ml in VIRGO I, and 412 cells/mm3 and 4.87 log10 copies/ml in VIRGO II. Using an intent-to-treat, 'non-completer equals failure', analysis, 78% (95% CI, 68-88%) of patients in VIRGO I and 68% (95% CI, 53-83%) of those in VIRGO II had a pVL <500 copies/ml at 24 weeks; the proportions achieving a pVL of <50 copies/ml were 62% (95% CI, 50-74%) and 50% (95% CI, 35-65%), respectively. The week 24 median CD4 cell count increase was 168 cells/mm3 (VIRGO I) and 139 cells/mm3 (VIRGO II). At week 52, 39/45 (87%) of VIRGO I patients had pVL <500 copies/ml and 30/45 (67%) <50 copies/ml. Of the 100 patients, 44 experienced grade 2 to 4 adverse events; 20 permanently discontinued study medication because of an adverse event. Combination therapy with the three reverse transcriptase (RT) inhibitors stavudine, once-daily didanosine and either once- or twice-daily nevirapine could be considered as an alternative option for first-line antiretroviral therapy.

Poisoning due to eating fungi in Victoria

OBJECTIVES

To determine the range of fungi eaten in Victoria and the incidence and severity of associated illness.

METHOD

From May 1997 to April 1999, 174 callers to the Victorian Poisons Information Centre who had eaten fungi posted samples for identification and 170 completed a questionnaire. The study was suspended for three months from 1 November 1997 to 10 January 1998 and for four months from 1 July 1998 to 30 October 1998.

RESULTS

Species categorised as: 'poisonous', 'possibly poisonous', 'hallucinogenic', 'possibly hallucinogenic' and 'coprine containing' or 'possibly coprine containing' were identified in 87/174 (50%) samples. Accidental ingestions: 55 types of fungus were identified in the 126 ingestions; Coprinus species were the most common (24/126 [19%]). Illness 'likely' or 'possibly' due to the fungi was reported in 13/126 (10%) of these ingestions. Deliberate ingestions: The fungi were eaten for food in 46/47 of these cases; 41 of these (89%) were Agaricus xanthodermus or other Agaricus species. Illness 'likely' or 'possibly' due to the fungi was reported in 40/47 (85%) deliberate ingestions. In one case the reason for ingestion was unknown.

CONCLUSIONS

A large range of fungi was eaten in the accidental ingestions; the incidence of illness was low. A small range of fungi was eaten deliberately. The predominant species was Agaricus xanthodermus, which was probably confused with other edible Agaricus species. The incidence of associated gastrointestinal irritation was high; it was of limited duration and mild severity.

Occupational exposure to blood: search for a relation between personality and behavior

OBJECTIVE

To describe the behavior of French nurses after occupational exposure to blood (OEB); to study the reasons for not reporting an OEB to the occupational medicine service or the hospital authorities, and to explore the links between personality traits and both the risk of having an OEB and the likelihood of reporting it.

DESIGN

A descriptive and correlational study using a cross-sectional survey for data collection.

SETTING

Six nursing schools (four initial training institutes and two specialty training schools, one for surgical nurses and one for nurse anesthetists) and six hospitals in Lorraine.

PARTICIPANTS

942 nurses and 459 nursing students were approached, and 964 (69%) replied to the questionnaire.

METHODS

The participants received an anonymous two-part questionnaire. The first part explored the knowledge of the risk and Standard Precautions and collected details of the history of OEB. Reporting of OEB to the occupational medicine service or the hospital authorities and the nature of serological monitoring after OEB also were explored. The second part was composed of the Zuckerman sensation-seeking scale, exploring four areas: disinhibition, danger- and adventure-seeking, seeking new experiences, and susceptibility to boredom.

RESULTS

947 nurses were vaccinated against hepatitis B, but only 528 (56%) had checked that they were effectively immunized. Only 166 respondents (17%) stated they routinely used gloves during all procedures in which they were exposed to blood. There were 505 recorded OEB during the study period (0.24 per person per year). The most frequently reported OEB were those involving hollow needles (57%). Approximately one half (48.5%) of all OEB were reported. "Good local antisepsis immediately after the accident" was the reason most often given to justify nonreporting. Only 57% of OEB victims sought to determine the serological status of the source patient for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus immediately after accident. Only 40% and 31% of OEB victims checked their own HIV and HCV serostatus 3 and 6 months after OEB, respectively. Few staff adopted safer-sex measures after OEB, and some continued to donate blood in subsequent months. Logistic regression identified two variables significantly and independently linked to the risk of having at least one OEB in the 27 months preceding the date on which the questionnaire was completed: having a permanent position and having a higher degree of disinhibition. Taking into account the number of OEB during this period (Poisson regression), four variables were significantly and independently linked to the risk of having a larger number of OEB: having a permanent position; having a higher degree of disinhibition; being more susceptible to boredom; and having less nursing experience. In logistic regression, three variables emerged as being significantly and independently linked to reporting all OEB: younger age; having had at least one percutaneous injury (excluding splashes); and having lower susceptibility to boredom.

CONCLUSION

Nursing personnel continue to ignore or be unaware of many factors surrounding OEB, meaning that information and counseling must continue unabated. Knowledge of the risk, of the benefit of respecting Standard Precautions, and of the importance of notification and serological follow-up is still inadequate. Finally, certain personality traits, such as a high level of disinhibition and susceptibility to boredom, appear to be linked to the risk of OEB. Subjects strongly susceptible to boredom are less likely to report such accidents.

Pregnancy-associated invasive squamous cell carcinoma of the vulva in a 28-year-old, HIV-negative woman. A case report

BACKGROUND

The incidence of invasive squamous cell carcinoma of the vulva in women under 40 years of age has been increasing, particularly in association with human papillomavirus. Invasive vulvar carcinoma is rare in women under 30, as is an association with pregnancy. We report on a 28-year-old woman who was diagnosed with invasive squamous cell carcinoma of the vulva during pregnancy.

CASE

The patient, gravida 5, para 4105, HIV negative, presented to the emergency room with vulvar pain. She had delivered a term infant three months earlier at another institution and was diagnosed with squamous cell carcinoma of the vulva at that time. At this admission, a 4.0-cm, ulcerated lesion involving the left labium minus was noted. The patient underwent examination under anesthesia with bilateral inguinal lymph node dissection, cone biopsy, radical vulvectomy and excision of perianal lesions.

CONCLUSION

This case demonstrates the need to biopsy all suspicious vulvar lesions, even in young and pregnant women.

Effect of subacute swainsonine (locoweed; Oxytropis sericea) consumption on immunocompetence and serum constituents of sheep in a nutrient-restricted state

The subacute dose-response effects of swainsonine (SW) consumption on immunocompetence and serum constituents of sheep in a nutrient-restricted state were investigated. Sheep (23 wethers, 5 ewes) were assigned to 1 of 5 SW treatments (0, 0.2, 0.4, 0.8, or 1.6 mg swainsonine/ kg bw/d). Swainsonine was delivered by feeding locoweed (Oxytropis sericea) with grama grass and alfalfa hays for a 28-d treatment period followed by a 21-d recovery period without locoweed. Body weights were measured weekly and behavioral changes were monitored for clinical signs of SW toxicity. Venous blood was collected weekly for lymphoblastogenesis and serum constituent analyses. Clinical signs (sluggishness, decreased responsiveness) of swainsonine toxicity were observed from d 14 to 35 in the 0.8 and 1.6 mg treatments. Subacute oral exposure did not appear to affect lymphoblastogenic analyses. Acute and subacute alterations in various serum constituents did indicate subclinical effects of SW ingestion. Linear, quadratic and cubic dose-response relationships were detected for some serum constituents (e.g., alkaline phosphatase, aspartate aminotransferase). Subacute SW consumption at the levels investigated does not seem to affect the immunocompetence of nutrient restricted sheep. The lack of change in serum alkaline phosphatase at the 0.2 mg SW/kg bw/d dose indicates the potential for a no adverse effect level of SW consumption in nutrient restricted sheep. In combination with measurable SW in serum, rises in serum alkaline phosphatase and aspartate aminotransferase activities, and declines in serum Fe and cholesterol during subacute exposure to SW establish these markers as potential indicators of subclinical SW toxicosis.

Patients, families, and organ donation: who should decide?

Although 69 to 75 percent of U.S. adults say they would be willing to become organ donors, half of the families that are asked to consider donating the organs of a deceased family member refuse to consent. This discrepancy is most noticeable when the refusal of a family conflicts with the known wishes of a patient. It is the practice of nearly all organ procurement organizations in the United States not to procure organs or tissue when families refuse, even if the patient's wishes have been documented. Recently, the Center for Organ Recovery and Education (CORE) adopted a controversial policy of acting on the documented wishes of individuals to donate, independent of family consent. An examination of the moral and political issues raised by this policy lead to the conclusion that the CORE policy is not only justified, but morally required.

[Mycobacterium avium complex disease in HIV seropositive patients: incidence and risk factors before and after the introduction of highly active antiretroviral treatments. Clinical Epidemiology Group of the Information and Care Center for Human Immunodeficiency]

The objective of this study was to determine the risk factors of the first occurrence of Mycobacterium avium complex disease (MAC) infection among human immunodeficiency virus (HIV)-infected subjects during two different time periods: before and after the introduction of protease inhibitor (respectively, period 1: 1 January 1992 to 31 December 1995, and period 2: 1 January 1996 to 30 June 1998). This study was performed using the French Hospital Database on HIV (FHDH). Subjects were included when their CD4+ cell count was less than 100/mm3. If they did not die or develop MAC within the first 6 months after the inclusion, their follow-up had to be longer than 6 months to be included. Cox's model was used to calculated the relative hazards (RH) of MAC occurrence according to the age and time-dependent variables, such as CD4+ below 50/mm3, previous occurrence of tuberculosis, cytomegalovirus (CMV) infection and other acquired immunodeficiency syndrome (AIDS)-defining disease, nature of antiretroviral treatment and MAC prophylaxis. Among the 14,779 subjects followed during period 1, 1,710 (11.6%) had a diagnosis of MAC infection during their follow-up (incidence: 8.4 +/- 0.2 for 100 persons per year), while only 453 (4.4%) among 10,239 subjects presented this infection during period 2 (2.8 +/- 0.1 for 100 persons per year). Rifabutin regular prescription was a protective factor of MAC occurrence during period 1 (RH = 0.51 95% confidence interval (CI) = [0.37-0.69]), whereas this protective effect was not observed during period 2 (RH = 1.05 CI = [0.63-1.67]). Thus, during the HAART period, the results that we present do not indicate an interest into continuing MAC prophylaxis.

Interictal EEG and ictal scalp EEG propagation are highly predictive of surgical outcome in mesial temporal lobe epilepsy

PURPOSE

Surgical outcome in patients with mesial temporal lobe sclerosis (MTS) is worse than that in patients with temporal lobe activity (TLE) with tumors. Previous studies of the ictal EEG focused on ictal EEG onset in scalp EEG or ictal EEG propagation in invasive recordings. Ictal EEG propagation with scalp electrodes has not been reported.

METHODS

Ictal scalp EEG propagation patterns were studied in 347 seizures of 58 patients with MTS or nonlesional TLE. Interictal epileptiform discharges (IEDs) and the presence of unilateral mesial temporal lobe atrophy in magnetic resonance imaging (MRI) also were studied in these 58 patients. Forty-nine patients were operated on (minimal follow-up of 1 year).

RESULTS

Postoperatively, seizure-free outcome was seen in (a) 82.8% of patients with regionalized EEG seizure without contralateral propagation, but in only 45.5% of patients with contralateral propagation (p = 0.007); (b) 84.6% of patients with 100% IED lateralized to one temporal lobe, but in only 52.2% with <100% unitemporal IED (p = 0.015); (c) 88.9% with 100% unitemporal IED and regionalized ictal EEG combined, 73.7% with one of both variables, and only 33.3% with <100% ipsitemporal IED combined with contralateral ictal EEG propagation (p = 0.007).

CONCLUSIONS

Switch of lateralization or bitemporal asynchrony in the ictal scalp EEG and bitemporal IED are most probably an index of bitemporal epileptogenicity in MTS and are associated with a worse outcome.

The effect of a methanogen, Methanobrevibacter smithii, on the growth rate, organic acid production, and specific ATP activity of three predominant ruminal cellulolytic bacteria

Three predominant ruminal cellulolytic organisms, Fibrobacter succinogenes S85, Ruminococcus albus 8, and R. flavefaciens FD-1, were cultured with a methanogen, Methanobrevibacter smithii. Growth rates, bacterial protein, organic acids, and methane production were measured. When grown in diculture with the methanogen, a fermentative advantage was observed with F. succinogenes S85 as seen by an increase in specific rate of ATP production and organic acid concentration. The introduction of the methanogen did not improve the growth rate, organic acid yield, or specific rate of ATP production for R. albus 8. The growth rate and amount of organic acid end products increased when R. flavefaciens FD-1 was cultured with the methanogen; however, the specific activity of ATP production did not increase.

14-3-3 proteins form a guidance complex with chloroplast precursor proteins in plants

Transit sequences of chloroplast-destined precursor proteins are phosphorylated on a serine or threonine residue. The amino acid motif around the phosphorylation site is related to the phosphopeptide binding motif for 14-3-3 proteins. Plant 14-3-3 proteins interact specifically with wheat germ lysate-synthesized chloroplast precursor proteins and require an intact phosphorylation motif within the transit sequence. Chloroplast precursor proteins do not interact with 14-3-3 when synthesized in the heterologous reticulocyte lysate. In contrast, a precursor protein destined for plant mitochondria was found to be associated with 14-3-3 proteins present in the reticulocyte lysate but not with 14-3-3 from wheat germ lysate. This indicates an unrecognized selectivity of 14-3-3 proteins for precursors from mitochondria and plastids in plants in comparison to fungi and animals. The heterooligomeric complex has an apparent size of 200 kD. In addition to the precursor protein, it contains 14-3-3 (probably as a dimer) and a heat shock protein Hsp70 isoform. Dissociation of the precursor complex requires ATP. Protein import experiments of precursor from the oligomeric complex into intact pea chloroplasts reveal three- to fourfold higher translocation rates compared with the free precursor, which is not complexed. We conclude that the 14-3-3-Hsp70-precursor protein complex is a bona fide intermediate in the in vivo protein import pathway in plants.

14-3-3 proteins form a guidance complex with chloroplast precursor proteins in plants

Transit sequences of chloroplast-destined precursor proteins are phosphorylated on a serine or threonine residue. The amino acid motif around the phosphorylation site is related to the phosphopeptide binding motif for 14-3-3 proteins. Plant 14-3-3 proteins interact specifically with wheat germ lysate-synthesized chloroplast precursor proteins and require an intact phosphorylation motif within the transit sequence. Chloroplast precursor proteins do not interact with 14-3-3 when synthesized in the heterologous reticulocyte lysate. In contrast, a precursor protein destined for plant mitochondria was found to be associated with 14-3-3 proteins present in the reticulocyte lysate but not with 14-3-3 from wheat germ lysate. This indicates an unrecognized selectivity of 14-3-3 proteins for precursors from mitochondria and plastids in plants in comparison to fungi and animals. The heterooligomeric complex has an apparent size of 200 kD. In addition to the precursor protein, it contains 14-3-3 (probably as a dimer) and a heat shock protein Hsp70 isoform. Dissociation of the precursor complex requires ATP. Protein import experiments of precursor from the oligomeric complex into intact pea chloroplasts reveal three- to fourfold higher translocation rates compared with the free precursor, which is not complexed. We conclude that the 14-3-3-Hsp70-precursor protein complex is a bona fide intermediate in the in vivo protein import pathway in plants.

Effects of etonitazene consumption and abstinence on the signal transmission of mu-opioid receptors in brain membranes of rats

Rats, for 8 weeks consuming the mu-opioid agonist etonitazene (forced and free choice conditions yielding high and low drug-consumers), were sacrificed after 2 days or 6 weeks lasting drug deprivation. Binding characteristics of membranes from the parieto-occipital cortex of these four groups were compared with those of drug-naive controls. In all five groups, 1 microM of the mu-opioid receptor agonist [D-Ala2,N-MePhe4,Gly5-ol]enkephalin (DAMGO) increased the guanosine-5'-O([35S]3'thio)triphosphate ([35S]GTPgammaS) binding activity on guanine nucleotide-binding (G) proteins, and 500 nM of GTPgammaS decreased the [3H]DAMGO binding affinity. During acute withdrawal, both opioid consuming groups displayed a higher maximum efficacy (Emax) in basal [35S]GTPgammaS binding (34 and 31%, each P < 0.01), but only the forced group showed a 58% higher net DAMGO-stimulated binding density Bmax (P < 0.01) and 53% more activated G proteins per mu-opioid receptor (P < 0.05). In the presence of GTPgammaS both groups revealed a higher affinity in [3H]DAMGO binding (each 25%, P < 0.01). The long-term drug-deprived groups displayed no differences in their binding characteristics.

Chloroplast precursor protein translocon

Chloroplasts are believed to have originated from a photosynthetic, prokaryotic ancestor. As the result of endosymbiotic evolution, most of the genes of the endocytobiont were displaced to the host nucleus. Today's chloroplasts must import most of their proteins from the cytosol as precursors. Oligomeric protein complexes in the chloroplast outer and inner envelope membranes are responsible for the specific recognition and membrane translocation of precursor proteins. The translocon at the outer membrane of chloroplasts and the inner membrane of chloroplasts act jointly during the import process. Several translocon subunits have been partially characterized in their molecular structure and function. Initial evidence indicates the prokaryotic origin of some chloroplast translocon components.

[Disseminated infestation of Enterocytozooon bieneusi a an HIV-infected patient]

An HIV-positive patient developed disseminated Enterocytozoon bieneusi infection. The parasite was identified in stool, duodenal biopsy, nasal discharge, and sputum specimens using transmission electron microscopy. Albendazole therapy failed to improve the symptoms or eradicate the parasite. The patient survived for nine months after the diagnosis of E. bieneusi infection.