Substitution mutations at the putative catalytic triad of the poliovirus 3C protease have differential effects on cleavage at different sites

Picornavirus 3C proteases are substrate-specific cysteine proteases, proposed to be homologous to the trypsin/chymotrypsin-like serine proteases on the basis of structural predictions. Substitutions at the putative active-site residues (Glu71 and Cys147) of the poliovirus 3C protease did not completely abolish proteolytic processing in vitro. The activity of mutated 3C proteases was in the following hierarchy: Glu71-Cys147 (wild type) > Asp71-Cys147 > Glu71-Ser147 > Gln71-Cys147 > Asp71-Ser147 > Gln71-Ser147 (inactive at all sites). Such mutations had differential effects on cleavage at different sites of the poliovirus polyprotein. Cleavage within the P1 region of the polyprotein was the most defective, at the 1ABC/VP1 junction and particularly at the VP0/VP3 junction. Cleavage at the 3AB/3CD and 2B/2C junctions was less affected by the mutations, and the P2/P3 and 2A/2BC junctions were cleaved efficiently by all mutants except Gln71-Ser147. All the 3C mutants gave negative results in infectivity and replication assays after transfection, indicating that mutation of Glu71 or Cys147 virtually abolishes viral replication, irrespective of the efficiency of processing of the nonstructural part of the polyprotein.

Hormonal factors in susceptibility to multiple sclerosis

Evidence implies that hormonal factors are involved in susceptibility to multiple sclerosis. Diseases associated with a class II allele occur more frequently in women than in men. Multiple sclerosis is more frequent in women, particularly in the early- and late-onset groups. Pregnancy has a favorable effect on the course of multiple sclerosis on both a short- and a long-term basis. Experimental allergic encephalomyelitis, an animal model with similarities to multiple sclerosis, is also influenced by hormonal factors in both occurrence and severity. The multiple levels of interaction between immune, endocrine, neurologic, and genetic systems probably explain the action of sex steroids in multiple sclerosis susceptibility.

Mechanisms of action of a second generation growth hormone-releasing peptide (Ala-His-D-beta Nal-Ala-Trp-D-Phe-Lys-NH2) in rat anterior pituitary cells

The mechanism by which GH-releasing peptides elicit GH secretion has remained largely unknown. In this study, the effects of a second generation GH-releasing peptide, Ala-His-D-beta Nal-Ala-Trp-D-Phe-Lys-NH2(GHRP-1), on cAMP, intracellular Ca2+ ([Ca2+]i), and GH release were examined using rat pituitary gland static monolayer cell cultures. It was found that GHRP-1 increased GH release in a dose-dependent manner up to 3-fold, while having no effect on cAMP levels. In contrast, simultaneous elevations of cAMP and GH were observed after treatment with GHRH. To further define the underlying mechanism of GHRP-1-mediated GH release, its effect on [Ca2+]i was determined using a fluorescent Ca2+ indicator, fura-2. GHRP-1 dose dependently increased [Ca2+]i up to 45.5 nM +/- 5.6 nM. A similar elevation of [Ca2+]i was observed after GHRH treatment. Similar to GHRH, GHRP-1-induced increases in [Ca2+]i and GH release were inhibited by somatostatin. Furthermore, the GHRP-1-induced increases in [Ca2+]i and GH were also suppressed by nifedipine. The interaction between the voltage-dependent Ca2+ channels and GHRP-1 was investigated in cells maximally stimulated by KCl. The addition of GHRP-1 had no effect on the KCl-stimulated GH release. To investigate the possible interaction between the adenylyl cyclase pathway and GHRP-1, cells were maximally stimulated with forskolin or (Bu)2cAMP. Addition of GHRP-1 stimulated GH release beyond that observed using cAMP elevating agents. Similar results were obtained in the presence of a protein kinase C, 4 beta-phorbol 12-myristate 13-acetate (PMA). The GHRP-1-stimulated GH release was additive to that observed with PMA stimulation. Based on these findings, it was concluded that 1) GHRP-1 treatment leads to an increase in [Ca2+]i; 2) unlike GHRH, GHRP-1 releases GH via a Ca(2+)-dependent, cAMP-independent mechanism; 3) GHRP-1-induced increases in [Ca2+]i and GH release are sensitive to somatostatin inhibition; and 4) cAMP-elevating agents and PMA have an additive effect on the GHRP-1-stimulated GH release, indicating these agents stimulate GH release via a mechanism separate from that of GHRP-1.

The needs and hopes for an AIDS vaccine

This article reviews the many difficulties met in the development of an effective vaccine against human immunodeficiency virus (HIV), including the considerable antigenic variability of the virus, its intracellular mode of transmission, its mucosal port of entry, and the persistent nature of the infection. Progresses in the development of prototype vaccines in animal models are discussed together with the results of initial clinical trials in human volunteers.

[Study of the remission period (between crises) of unipolar and bipolar manic depressive disorders. Personal study of 95 patients]

The personality abnormalities observed during unipolar and bipolar manic-depressive disorders are known for years by german psychiatry as depressive temperament. In USA many works based on DSM III criteria have studied personality abnormalities coexisting with depression. The most frequently abnormalities are dependent, avoidant, compulsive, border line personality, observed with a frequency of 48% (P.A. Pilkonis) to 74% of patients (T.M. Shea et al.). But the personality traits or disorders are not the disorders only observed during remissions and intercrisis. Our personal work have studied the other disorders. This work concern pre-morbid period and intercrisis of 95 manic-depressed patients (45 unipolar and 50 bipolar patients). The time of remission is at least three months. Remission is certified by maximum scores of 10 on MADRS, 12 on Bech-Rafaelsen scale. The study of personality traits and other mental disorders is based on DSM III-R criteria. It is completed by Hamilton-Anxiety-Scale, Eysenck Personality Inventory and Beth-Israel Questionnaire of Sifneos. This study shows the following results. In pre-morbid period, the anxiety disorders are statistically more frequent in unipolar patients: generalized anxiety (35%), panic disorder (27%), psychosomatic disorders (30.5%). During intercrisis, the anxiety disorders are statistically more frequent in unipolar patients: generalized anxiety (51.1%), agoraphobia (31.1%) obsessive disorders (26.6%), panic disorder (18.2%). But this co-morbidity with anxious disorders is highly correlated with the incomplete characteristic of remission. During remission the personality abnormalities are similar to american studies, more frequent in unipolar patients, particularly obsessive personality (22.2 to 4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Intracellular pH on protein kinase C and ionomycin potentiation of isoproterenol-stimulated cyclic AMP and cyclic GMP production in rat pinealocytes

In rat pinealocytes, alpha 1-adrenergic activation, which leads to cytoplasmic alkalinization, also potentiates the beta-adrenergic stimulated cyclic AMP (cAMP) and cyclic GMP (cGMP) responses. Both elevation of intracellular calcium ([Ca2+]i) and activation of protein kinase C are involved in the potentiation mechanism. Recently, intracellular pH has also been found to modulate the adrenergic-stimulated cyclic nucleotide responses, suggesting intracellular pH may also affect the potentiation mechanism. This possibility was examined in the present study. Cytoplasmic alkalinization by ammonium chloride had an enhancing effect on the isoproterenol and ionomycin-stimulated cAMP and cGMP accumulation. In comparison, cytoplasmic acidification by sodium propionate reduced the isoproterenol and ionomycin-stimulated cAMP and cGMP responses. Direct measurement of [Ca2+]i indicated that neither ammonium chloride nor sodium propionate had an effect on the ionomycin-stimulated elevation of [Ca2+]i, suggesting their effects on cyclic nucleotide responses may be independent of [Ca2+]i. In cells stimulated by isoproterenol and an activator of protein kinase C, ammonium chloride had an enhancing effect on both cAMP and cGMP responses, whereas sodium propionate had no effect. Taken together, these results suggest that a site distal to elevation of [Ca2+]i and activation of protein kinase C, of importance to the potentiation mechanism, is modulated by intracellular pH.

Expression and secretion of Japanese encephalitis virus nonstructural protein NS1 by insect cells using a recombinant baculovirus

The nonstructural protein NS1 of Japanese encephalitis virus (JEV) was expressed at a high level under the control of the polyhedrin promoter in Spodoptera frugiperda (Sf9) insect cells using a recombinant baculovirus. Recombinant NS1 was designed to contain its natural signal sequence at its N-terminus and no C-terminal hydrophobic domain that could act as a membrane anchor. This recombinant protein exhibited similar size to native NS1 expressed in Aedes albopictus (C6/36) insect cells infected with wild-type JEV. The signal sequence of NS1 allowed translocation of the protein into the endoplasmic reticulum where it underwent glycosylation. A small fraction of synthesized NS1 was able, in the absence of any other viral protein, to associate as a homodimer, showing similar characteristics to the native dimer. Interestingly, this recombinant dimeric form seemed to be exported and released in the extracellular medium of infected cell culture. During its transport, one of the two N-linked oligosaccharides of the polymannose type was processed to an endoglycosidase H-resistant form, suggesting that the protein had passed through the Golgi compartment before reaching the cell surface. Moreover, Triton X-114 partitioning analysis showed that monomeric NS1 behaved essentially as a hydrophilic protein, whereas both intracellular and extracellular dimeric NS1 were either free of or associated to membraneous components.

The increased susceptibility of women to multiple sclerosis

Many diseases with an auto-immune etiology have a skewed sex distribution. In the majority of instances, women are affected more frequently than men. A review of population studies demonstrates that the preponderance of women in multiple sclerosis (MS) is almost constant. We show that this preponderance is further increased in early as well as in late-onset cases, in familial cases as well as in MS twin pairs and that the HLA-DR2 allele, which has been associated with MS in Caucasian populations, is significantly more frequent in women than in men with MS. "Rules" have been established for multifactorial diseases; MS contravenes most of those rules. The skewed sex distribution in MS could be attributed to the known hormonal and gender influences on the immune response, as well as to genetic influences.

Intracellular pH and growth hormone-releasing factor-stimulated adenosine 3'5'-monophosphate, intracellular calcium and growth hormone release from rat anterior pituitary cells

In this study, we examined the effect of changes in intracellular pH (pHi) on basal and GH-releasing factor (GRF)-stimulated cyclic AMP (cAMP), intracellular Ca2+ and GH release using a static monolayer culture prepared from dispersed rat anterior pituitary cells. To modulate pHi, two approaches were used: variation of extracellular pH (pHo) and addition of sodium propionate and ammonium chloride which alter pHi directly. Direct pHi measurement with 2'7'-bis(carboxyethyl)-5(6)-carboxyfluorescein showed that for pHo values between 6.9 and 7.6, a change in pHo of 0.1 units resulted in a change in pHi of 0.045 units. Sodium propionate (30 mmol/l) reduced pHi by 0.06 units whereas ammonium chloride (30 mmol/l) increased pHi by 0.1 units. Increasing pHo from 6.6 to 7.8 enhanced the maximal GRF-stimulated cAMP and GH responses by 80% and 300% respectively, indicating that the GRF-stimulated cAMP and GH release were both pH-dependent. Acute elevation of pHo from 6.6 to 7.8 also increased basal GH release by sixfold. Reduction of pHi by sodium propionate, however, had no significant effect on GRF-stimulated cAMP levels while the corresponding GRF-stimulated GH release was reduced by up to 40%. In comparison, elevation of pHi by ammonium chloride enhanced the GRF-stimulated cAMP release by up to 75% and the corresponding increase in GH was less than 20%. When the relationship between pHi and intracellular Ca2+ was determined with the fluorescent Ca2+ indicator, Fura-2, it was found that increasing pHo and treatment with ammonium chloride increased intracellular Ca2+, while sodium propionate and reducing pHi had no effect on intracellular Ca2+. These results indicate that activation of adenylate cyclase and mobilization of intracellular Ca2+, two intracellular signalling pathways of importance to GH secretion, are both sensitive to changes in pHi.

Profiles of alcoholics according to the SCL-90-R: a confirmative study

The Symptom Checklist-90-Revised (SCL-90-R) has often been used in studies of alcoholic populations. Based on findings reported in the literature and data gathered on 712 alcoholics in treatment, this paper investigates the general trends in the responses of alcoholics to the SCL-90-R. On global measures as well as on each of the symptom scales, the scores of alcoholic groups reveal a symptomatology two to five times as severe as that observed in the general population. The Psychoticism dimension shows the most marked divergence with the general population. In almost each of the study groups, the Depression Scale registers the highest scores, followed by Obsessive-Compulsive, Interpersonal Sensitivity, and Anxiety.

Inhibitory action of ethanol on L-type Ca2+ channels and Ca(2+)-dependent guanosine 3',5'-monophosphate accumulation in rat pinealocytes

It has previously been shown that the K+ potentiation of vasoactive intestinal peptide-stimulated cAMP and cGMP responses was inhibited by ethanol in rat pinealocytes, suggesting an inhibitory action of ethanol on the voltage-dependent Ca2+ channels (VDCC). In this study, using the whole cell version of the patch clamp technique, we found that ethanol reduced the amplitude, but did not change the voltage dependence or the time course of activation or inactivation of the L-type VDCC. The inhibitory effect of ethanol on this current was concentration dependent, and ethanol (100 mM) resulted in a 40% inhibition of this current. However, in fura-2-loaded cells, total increases in intracellular Ca2+ ([Ca2+]i) caused by ethanol and BayK 8644 did not differ from the [Ca2+]i signal caused by BayK 8644 alone, suggesting that the inhibitory action of ethanol on VDCC may not be related to a reduction in [Ca2+]i. Although there was no change in the total [Ca2+]i signal, ethanol (25-200 mM) dose-dependently inhibited the potentiation effects of depolarizing concentrations of K+ and BayK 8644 on the isoproterenol-stimulated cGMP, but not the cAMP, response. Therefore, the cGMP response appears to be more sensitive to the inhibitory action of ethanol, and a site distal to elevation of [Ca2+]i of importance to the potentiation mechanism may be inhibited by ethanol. This was confirmed by the finding that ethanol was effective in inhibiting the A23187 potentiation of isoproterenol-stimulated cGMP response. These results suggest that 1) the L-type VDCC was inhibited by ethanol; 2) the Ca(2+)-mediated potentiation of the isoproterenol-stimulated cGMP response was sensitive to the inhibitory action of ethanol; and 3) although ethanol inhibits the VDCC, it alone cannot explain the inhibitory effect of ethanol on BayK 8644- and K(+)-mediated potentiation of the isoproterenol-stimulated cGMP response.

Differential effects of intracellular calcium elevating agents on adrenergic-stimulated cyclic nucleotide and melatonin synthesis in rat pinealocytes

In this study, the role of elevation of intracellular Ca2+ and activation of protein kinase C on adrenergic-stimulated cyclic nucleotide accumulation and melatonin synthesis in rat pinealocytes was investigated. It was found that whereas KCl, ionomycin, and ouabain, three Ca(2+)-elevating agents, had a potentiating effect on adrenergic-stimulated cyclic AMP response, their effects on melatonin synthesis were inhibitory. Similar inhibition was also observed when dibutyryl cyclic AMP was used to stimulate melatonin synthesis. By determining intracellular Ca2+ directly, it was found that the enhancing effects of these agents on the cyclic AMP response but not their inhibitory effects on melatonin synthesis paralleled their abilities to elevate intracellular Ca2+. In comparison, activation of protein kinase C significantly enhanced the adrenergic-stimulated cyclic AMP response and, to a lesser degree, the adrenergic-stimulated N-acetyltransferase and melatonin levels. These results indicate that (i) Ca(2+)-elevating agents have opposite effects on adrenergic-stimulated cyclic AMP and melatonin production; (ii) a post cyclic AMP event of importance to melatonin synthesis is inhibited by these agents; and (iii) the mechanism of inhibition may not be directly related to their effect on intracellular Ca2+.

Analysis of the functional significance of amino acid residues in the putative NTP-binding pattern of the poliovirus 2C protein

The amino acid sequence of the poliovirus 2C protein contains two highly conserved stretches, GSPGTGKS136 and MDD177, which correspond to the consensus 'A' and 'B' motifs (GXXXXGKS/T and DD/E, respectively) found in nucleoside triphosphate-binding proteins. To assess the functional importance of these amino acid sequences, we changed conserved and non-conserved amino acids. The replacement of the non-conserved Thr133 residue with Ser or Ala did not markedly change the virus phenotype. Similarly, replacement of the non-conserved Pro131 residue by Ala did not abolish virus viability, but changes of this residue to Thr or Asn were not tolerated. No viable mutant could be isolated after transfection of cultured cells with transcripts mutated at the conserved Lys135, Ser136 or Asp177 residues. However, true revertants were selected from Arg135 and Ser135 mutants, from Glu177 and Gly177 mutants, and from Ala136 mutants. Thr136 mutants not only gave rise to true revertants, but also to two independent isolates of a suppressor mutant, Asn140----Tyr. All the lethal mutations resulted in severe inhibition of viral RNA synthesis in vivo, although no translational deficiency was detected in a cell-free system. This is the first direct evidence for the functional significance of the nucleoside triphosphate-binding pattern in the poliovirus 2C protein.

Vaccine protection of chimpanzees against challenge with HIV-1-infected peripheral blood mononuclear cells

Because human immunodeficiency virus (HIV) can be transmitted as cell-free virus or as infected cells (cell-associated virus), vaccines must protect against infection by both viral forms. Vaccine-mediated protection of nonhuman primates against low doses of cell-free HIV-1, HIV-2, or simian immunodeficiency virus (SIV) has been demonstrated. It is now shown that multiple immunizations of chimpanzees with HIV-1 antigens protected against infection with cell-associated virus. Protection can persist for extended periods (one animal had not been exposed to viral antigens for 1 year before challenge). These results show that it is possible to elicit long-lasting protective immunity against cell-associated HIV-1.

High-titer HIV-1 neutralizing antibody response of rhesus macaques to gp160 and env peptides

Three groups of four rhesus macaques were immunized twice, one month apart with purified recombinant HIV-1LAI gp160 in the presence of either alum, incomplete Freund's adjuvant (IFA), or SAF-1. Two months later, the animals were injected twice again with a synthetic peptide with the sequence of the principal neutralization determinant (PND) of the HIV-1LAI isolate mixed with the same adjuvants. All animals received a booster injection of gp160 and PND peptide at 6 months. This regimen of immunization induced in the SAF-1 and IFA groups a high-titer neutralizing antibody response that declined progressively over the course of the following 6 months. In contrast, only a weak response was observed in the alum group. Neutralizing antibody titers varied as anti-PND titers, suggesting that they were principally targeted to the PND. A shortened immunization protocol comprising two injections of gp160 at 0 and 1 month followed by one injection of PND peptide at 3 months is suggested as optimal for the induction of high titers of HIV-1 neutralizing antibodies in primates.

[Experimental vaccination against HIV-1 protects the chimpanzee against challenge with injections of infected lymphocytes]

Two chimpanzees were immunized against HIV-1 : C-339, using whole inactivated HIV-1 followed by purified recombinant gp160 and a KLH-V3 peptide conjugate; and, C-499, using purified recombinant gp160 and p18gag followed by a mixture of uncoupled V3 peptides. The antigens were emulsified prior to use with one volume Syntex adjuvant SAF-1 containing 1 mg/ml Threonyl-MDP. The animals were challenged twice one year apart by the intravenous route, the first time with cell-free virus, using 40 chimpanzee infectious units (100 TCID50) of the titrated HTLV-IIIB virus stock from the National Cancer Institute, Frederick, MD; and the second time with cell-associated virus, using 6 x 10(5) viable peripheral blood mononuclear cells (PBMC) from a naive chimpanzee which had been injected 3 months earlier with cell-free virus and had become virus-positive within a few weeks. From end-point titration of C-087 PBMC on indicator human PBMC, using a reverse transcriptase assay, this represented the equivalent of at least 15 infected cells. A 3rd chimpanzee, C-435, a näive animal, was also injected with 6 x 10(5) PBMC from C-087 to serve as a positive control. The PMBC of the animals were co-cultivated with fresh human PBMC and assayed for reverse transcriptase on a regular basis. In parallel, ELISA and Western blot analyses were carried out. Virus was detected in the PBMC from C-435 beginning at 4 weeks after challenge. This was followed by seroconversion of the animal to the Env and Gag antigens. By contrast, no virus could be detected in the PBMC from chimpanzees C-499 and C-339 during 7 and 12 months, respectively. Lymph node biopsies and bone marrow aspirates from these animals remained virus-negative upon co-cultivation with human PBMC. PBMC, bone marrow aspirates and lymph node biopsies also scored HIV-negative by polymerase chain reaction. Finally, no anamnestic antibody response of the animals could be detected by ELISA, and no modification of their western blot profiles that could have signed HIV-infection were observed during the follow-up period. C-499 accidentally developed an infectious endocarditis with congestive liver and kidney failure and had to be euthanized at 7 months post-challenge. Specimens from its brain, kidneys, liver, mesenteric nodes, pancreas, salivary glands, and spleen were processed for co-cultivation with human PBMC. No evidence for the presence of virus could be detected by reverse transcriptase assays in any of these co-cultures.(ABSTRACT TRUNCATED AT 400 WORDS)

The Influence Of Reservoir Wettability On Waterflood And Miscible Flood Performance

Abstract

Laboratory waterflood and miscible flood data of three Alberta reservoir systems are compared with their respective field projections. Trends in laboratory waterflood and miscible flood recoveries were found to correspond closely with the expected ultimate recoveries in the respective fields and to correlate well with reservoir wettability. The wettability, as characterized by measuring water-oil relatie permeabilities, ranged from strongly water-wet to strongly oil-wet with one system of intermediate wet/ability and another of probable mixed wettability. Miscible flood oil recoveries were high in systems possessing other than strongly water-wet nature. In addition to the water-shielding phenomenon, interfacial adhesion is also considered to gain a better understanding of the wettability effects in miscible gas processes.

The results of this study could be used to identify candidate reservoirs for carrying out miscible floods and to re-evaluate the need for secondary waterfloods in certain reservoirs. In some reservoirs where mixed wettability conditions exist extended waterfloods, within economic limits, may not adversely affect the potential for future miscible floods. This paper brings forth the significant role played by wettability in miscible processes and also offers insight into strategic alternatives for field applications.

Introduction

Reservoir wettability is an important factor among the many that affect the design of a miscible enhanced oil recovery process. Wettability influences the extent of access of oil by the injected miscible solvent through its effect on the relative location of oil and water. This, in turn, will influence miscible flood performance.

The influence of wettability on waterflood performance has been studied for several decades(l) and the published literature supports widely differing conclusions leading to some uncertainty. These uncertainties did not seem important as long as there existed a belief that all petroleum reservoirs were strongly water-wet. Many researchers have contributed significant findings over the last few decades to dispel this belief. It is now generally accepted that reservoir wettabilities vary widely between the extremes of strongly water-wet and strongly oil-wet states, with many falling in the mid-band of neutral or intermediate wettability where the rock shows equal preference to both oil and water- None of these homogeneous wettability states could explain the high waterflood recoveries in the East Texas Woodbine core displacement tests. Efforts to explain these results culminated in the concept of "mixed wettability" which was introduced by Salathiel in 1973(2). This mixed wettability state has also been recently assigned to the Pembina Cardium field in Alberta(3).

What is the influence of these widely differing wettability states of petroleum reservoirs on their waterflood and miscible flood behaviour? Despite such a wide variation in reservoir wettability, should we continue to adopt the same sequence of production strategies namely secondary waterfloods and tertiary miscible floods? Or could we optimize our production strategies for maximum benefit by a better understanding of the influence of wettability on secondary and tertiary oil recoveries? This study attempts to address these concerns.

This paper begins with the role of wettability in miscible enhanced oil recovery (EOR) operations wherein the literature dealing with this subject is reviewed.

Poliovirus chimeras expressing sequences from the principal neutralization domain of human immunodeficiency virus type 1

Sequences from the principal neutralization domain of human immunodeficiency virus type 1 (HIV-1) strain LAI or RF have been expressed in antigenic site 1 of the capsid of the Sabin strain of poliovirus type 1. A number of the resulting chimeras were viable. Viable variants bearing mutations within the insertion site spontaneously arose from several nonviable chimeras. In general, these mutations result in a decrease in positive charge in the substituted antigenic site 1. Two of the chimeras were genetically stable and have been further characterized. Both chimeras were neutralized by various HIV-1 neutralizing antibodies. In rabbits, both chimeras produced high levels of antibodies which react with HIV-1 gp120/160 in immunoprecipitation and enzyme-linked immunosorbent assays. One of the chimeras (HIV-1LAI) produced a significant but weak HIV-1 neutralizing response.

Assessment of behavioural objectives in anaesthesia resident training

Residency training must be based on a comprehensive curriculum. Educators use the term behavioural objectives to represent educational objectives stated as behaviours that must be accomplished by the students. Educational objectives represent an important part of the curriculum content. However, curriculum content, as defined in large academic departments, has often been described as irrelevant for practitioners outside these large centres. Behavioural objectives drawn for the year of internal medicine, the fourth year of a five-year specialty programme in anaesthesia, were evaluated for their clinical relevance for anaesthetists in clinical practice outside cities where teaching programmes are found in the province of Québec. A questionnaire based on 288 objectives, using a rating scale, was used to compare the opinions of the members of the Education Committee (6) and outside practitioners (24). There were no significant differences between the mean ratings of the two groups of raters on ten of the 14 groups of objectives. A concordance of opinion was also present when there was disagreement with the importance of certain objectives. There was disagreement with only one group (VIII) of objectives on 14. Within this group there was agreement with the clinically oriented objectives and disagreement with the laboratory oriented objectives. Objectives that were related to the acute aspects of illness were rated higher than those related to their chronic aspects. The outside practitioners made 81 suggestions or comments about the objectives.

[Methodological obstacles encountered in the evaluation of psychotherapies of schizophrenic patients. A general review]

Through a critical review of literature, authors suggest a methodological reflexion about problems in evaluation of effects of psychotherapies of schizophrenics, taking into account not only individual techniques but also institutional ones with psychotherapeutic orientations. Among the main difficulties are: evaluation with too much unspecific and over simplified criteria, for example criterium of rehospitalisation; lack of real comparability between groups, or techniques, and lack of validity of randomisation, still considered as a pawn of methodological rigour; diversity of levels of experience, and education of therapists, too unmatched model of functional organisation of the different centers, and in the same time too unequal recruitment of patients and at length of proposed therapeutic programs. Moreover, and even before these methodological bias, a more basic obstacle must be considered. It is the non-opening of models to the falsification, denounced by Bignami as the impossible verification of the heuristic value of the proposed models, ie the impossible verification of the utility of the proposed programs for individual therapies of schizophrenics.

Evidence for a substance P containing subpopulation in the primate suprachiasmatic nucleus

Immunohistochemical detection of substance P (SP) in the suprachiasmatic nucleus (SCN) of the Old World monkey, Macaca fascicularis, was performed using two different rabbit polyclonal antisera. Immunostaining revealed a large population of neurons located in the dorsal subdivision of the nucleus identified by Nissl stain. This neuronal group represents the only cluster of SP-like immunoreactive (SP-IR) perikarya observed within the hypothalamus. In contrast with our present finding in the macaque, earlier studies only reported a few scattered SP-IR neurons in the SCN of other mammalian species. In agreement with previous descriptions of neuropeptides in the SCN, the topographical distribution of SP-IR neurons in the monkey confirms that cellular segregation is a significant feature of the mammalian SCN. This particular peptidergic subpopulation may represent a characteristic of the monkey circadian pacemaker. Together with other anatomical data previously reported in monkey and man, this finding also relates to the anatomical evolution of the circadian system from non-primates to humans. Although convincing data support the implication of SP in cyclic neuroendocrine regulations, the role of this tachykinin in circadian rhythmicity remains to be elucidated.

Transient increases in numbers of infectious cells in an HIV-infected chimpanzee following immune stimulation

Efficient replication and production of human immunodeficiency virus (HIV) has been shown to be influenced greatly not only by the activation state of the infected cell but also by a variety of cytokines. Thus, it seems reasonable to assume, as has been hypothesized, that any stimulus to the immune system, whether by intercurrent infection, exposure to new or recall antigens, or injury with inflammation, could enhance HIV expression in infected individuals. To test this hypothesis, we subjected an HIV-1-infected chimpanzee to repeated specific and nonspecific immune stimulation by inoculation of various vaccine preparations, adjuvant alone, or HIV-specific immune globulin. Transient increases both in numbers of infectious peripheral blood cells and in some HIV-specific immune responses occurred within 1 to 2 weeks after most inoculations, including administration of the immune globulin. These results have important implications for the use of immunotherapy as a treatment for HIV-infected persons and for immunization of HIV-infected infants and children against other pathogens. They suggest that both immunotherapy and vaccination of HIV-infected individuals should be accompanied by administration of an antiviral drug(s).

Antibodies of HIV-1 positive subjects and experimentally immunized primates and rodents bind to sequence divergent regions of the third variable domain (V3) of gp120

Several motifs have been found to be the target of the neutralizing antibody response to HIV, the human immunodeficiency virus. One of the well characterized motifs maps to a loop within the third hypervariable region (V3) of the exterior envelope glycoprotein gp120 at amino acid positions 308-331 and is referred to as the principal neutralizing determinant (PND). The sequence of this V3 loop raises the question of the immunogenicity and the degree of diversity of the antibody response to the PND. We show here that this neutralization-related motif is highly immunogenic in HIV-positive subjects and in experimentally immunized primates and rodents submitted to various anti-HIV immunization regimens. In probing the diversity of the antibody response to PNDs corresponding to 11 HIV sequence-divergent isolates in serum samples of 101 HIV-positive individuals we found that human antibodies exhibit binding affinity to up to nine PND synthetic peptides. This antibody binding was in all cases tested inhibitable by the homologous PND synthetic peptide. We additionally demonstrate that this antibody cross-reactivity towards sequence-divergent PNDs is detectable in the sera of mice and chimpanzees experimentally immunized against a single HIV-1 isolate. Finally, we noticed that there is a hierarchy of reactivity among the various PNDs wherein the synthetic peptide corresponding to the MN isolate was generally the most prominently recognized by antibodies of human, non-human primate, and rodent origins. Based on these findings and on features of the sequences analyzed we suggest that, despite its overall sequence variability, the PND encompasses conserved amino acid positions or epitopes that are the targets of antibodies recognizing sequence-divergent isolates. We also propose that the high positive charge density of the most frequently recognized PNDs and the high antigenicity value of some of their residues are critical to the broad immunoreactivity of this neutralization-related motif.

[Nursing problems in intensive care for psychiatric patients]

Two cases illustrate psychotherapeutic aspects of surgical intensive cares for psychiatric patients. Comparison with their style of expression in art-therapy allows a better understanding in their relations with the technical and non human environment.