Immunity to Trichinella spiralis infection in vitamin A-deficient mice.

Vitamin A-deficient (A-) mice make strikingly poor IgG responses when they are immunized with purified protein antigens. Previously, we showed that A- T cells overproduce interferon gamma (IFN-gamma), which then could inhibit interleukin 4 (IL-4)-stimulated B cell IgG responses. To determine if the altered IFN-gamma regulation pattern and its immunological consequences would extend to a natural infection, we studied mice infected with the parasitic helminth Trichinella spiralis. The course of the infection was similar in A- and A-sufficient (A+) mice. These mice did not differ with respect to newborn larvae/female/hour produced in the intestine, or muscle larvae burden 5 wk postinfection. They also did not differ in the intestinal worm expulsion rate until day 15, when A- mice still harbored parasites, whereas A+ mice had cleared intestinal worms. Vitamin A deficiency reduced both the frequency of B lymphocytes secreting IgG1 antibodies to parasite antigens, and the bone marrow eosinophilia associated with helminth infection. The cytokine secretion patterns in infected mice were consistent with these observations and with previous studies. Mesenteric lymph node cells from infected A- mice secreted significantly more IFN-gamma, and significantly less IL-2, IL-4, and IL-5 than infected A+ controls. A- splenocytes secreted significantly more IFN-gamma, and equivalent amounts of IL-2, IL-4, and IL-5 compared with A+ controls. Interestingly, CD4-CD8- cells secreted the majority of the IL-4 produced in the spleen. The IL-2, IL-4, and IL-5 steady-state transcript levels correlated with secreted protein levels, but IFN-gamma transcripts did not. Although they secreted more protein, A- cells contained fewer IFN-gamma transcripts than A+ cells. These results suggest two vitamin A-mediated regulation steps in IFN-gamma gene expression: positive regulation of IFN-gamma transcript levels, and negative regulation posttranscriptionally. The essentially unaltered outcome of T. spiralis infection in vitamin A-deficient mice probably reflects a balance between cellular and humoral responses. The IFN-gamma overproduction might have a positive effect on the gut inflammatory response, but the decrease eosinophilia, cytokine production in mesenteric lymph node, and IgG1-secreting cell frequency might have a negative effect on T. spiralis immunity.

Distinct mechanism for antidepressant activity by blockade of central substance P receptors.

The localization of substance P in brain regions that coordinate stress responses and receive convergent monoaminergic innervation suggested that substance P antagonists might have psychotherapeutic properties. Like clinically used antidepressant and anxiolytic drugs, substance P antagonists suppressed isolation-induced vocalizations in guinea pigs. In a placebo-controlled trial in patients with moderate to severe major depression, robust antidepressant effects of the substance P antagonist MK-869 were consistently observed. In preclinical studies, substance P antagonists did not interact with monoamine systems in the manner seen with established antidepressant drugs. These findings suggest that substance P may play an important role in psychiatric disorders.

Role of EGR1 in regulation of stimulus-dependent CD44 transcription in B lymphocytes.

The immediate-early gene egr-1 encodes a transcription factor (EGR1) that links B-cell antigen receptor (BCR) signals to downstream activation events through the regulation of previously unidentified target genes. Here we identify the gene encoding the lymphocyte homing and migration protein CD44 as a target of EGR1 regulation in B cells. BCR-induced increases in CD44 mRNA expression and transcription levels are shown to occur in EGR1-expressing but not in nonexpressing subclones of the B-cell line WEHI-231. Kinetics of egr-1 transcription and the appearance of nuclear EGR1 protein precede CD44 induction and occur within 30 min after stimulation in the EGR1-expressing subclone. A single EGR1 binding motif is demonstrated at bp -301 of the human CD44 promoter. Cotransfection of a CD44 promoter-chloramphenicol acetyltransferase reporter construct with an egr-1 expression vector resulted in a 6.5- to 8.5-fold induction of transcriptional activity relative to an empty expression vector. The EGR1 binding motif was shown to be necessary for stimulus-induced expression of a CD44 promoter-chloramphenicol acetyltransferase reporter construct in nontransformed B lymphocytes and was required for transactivation by an EGR1 expression vector in a B-cell line. These studies identify EGR1 as an intermediary linking BCR-derived signals to the induction of CD44. The relevance of these molecular events to BCR signal transduction and antigen-stimulated B-cell-mediated immune responses is discussed.

Use of calcitonin in psychotic agitation or mania.

Synthetic salmon calcitonin was administered subcutaneously to 12 inpatients with several primary psychotic diagnoses. Increases in serum total calcium and inorganic phosphorus levels and decreases in CSF calcium level had earlier been observed during periodic psychotic agitation or mania. By contrast, calcitonin, which decreased serum calcium and phosphorus levels and increased CSF calcium level, appeared to produce transient (24-hour) increases in depression and decreases in arousal in this double-blind placebo-controlled trial. Quantitative activity monitoring confirmed the rater's impression that this agent had tranquilizing or depressant effects in such patients. When given in the evening, this polypeptide also appeared to delay sleep onset, as demonstrated both by nurses' 30-minute sleep checks and by the same longitudinal activity record. A decreased hypocalcemic response to calcitonin was noted in the agitated patients, which might explain the increases in serum calcium level described at the "switch".

Effects of a dopamine agonist piribedil in depressed patients: relationship of pretreatment homovanillic acid to antidepressant response.

Piribedil, a compound that stimulates dopamine receptors in a relatively specific fashion, was administered to 11 hospitalized depressed patients. The dopamine agonist significantly decreased rapid eye movement (REM) sleep and percent REM sleep and increased REM latency. Piribedil decreased the probenecid-induced accumulation of the dopamine metabolite homovanillic acid (HVA) in CSF. A range of mild to moderate antidepressant effects was noted; one patient worsened and one developed recurrent manic episodes. The degree of improvement in depression was negatively correlated with pretreatment values of HVA in CSF (r = -.66, P less than .05). These data suggest that the heterogeneity of clinical response may be related to biological differences in depressed patients and that those with low initial dopaminergic function respond best to increased dopamine receptor stimulation.

Developmental, nutritional and hormonal anomalies of weightlessness-grown wheat.

The behavior of water in weightlessness, as occurs in orbiting spacecraft, presents multiple challenges for plant growth. Soils remain saturated, impeding aeration, and leaf surfaces remain wet, impeding gas exchange. Herein we report developmental and biochemical anomalies of "Super Dwarf" wheat (Triticum aestivum L.) grown aboard Space Station Mir during the 1996-97 "Greenhouse 2" experiment. Leaves of Mir-grown wheat were hyperhydric, senesced precociously and accumulated aromatic and branched-chain amino acids typical of tissues experiencing oxidative stress. The highest levels of stress-specific amino acids occurred in precociously-senescing leaves. Our results suggest that the leaf ventilation system of the Svet Greenhouse failed to remove sufficient boundary layer water, thus leading to poor gas exchange and onset of oxidative stress. As oxidative stress in plants has been observed in recent space-flight experiments, we recommend that percentage water content in apoplast free-spaces of leaves be used to evaluate leaf ventilation effectiveness. Mir-grown plants also tillered excessively. Crowns and culms of these plants contained low levels of abscisic acid but high levels of cytokinins. High ethylene levels may have suppressed abscisic acid synthesis, thus permitting cytokinins to accumulate and tillering to occur.

Calcium: bivalent cation in the bivalent psychoses.

Decreases in cerebrospinal fluid (CSF) calcium accompany mood elevation and motor activation in depressed patients undergoing treatment with ECT, lithium, and total sleep deprivation. Similarly, decreases in CSF calcium occur during acute psychotic agitation or mania. On the other hand, periodic recurrences of such agitated states are accompanied at their onset by transient increases in serum calcium and phosphorus. Several observations suggest that such serum ion shifts may trigger the more enduring and opposite shifts in CSF calcium and, in turn, the manic behavior. Progressive restriction of dietary calcium was earlier reported to mitigate and finally abolish both rhythmic rises in serum calcium and periodic agitated episodes in one psychotic patient. Lithium, which decreases the efficiency of alimentary calcium absorption, may function similarly. Conversely, a modest oral calcium lactate supplement (approximately one additional Recommended Daily Allowance of dietary calcium) seemed to slightly intensify agitation in six patients. Dihydrotachysterol (DHT), an analogue of vitamin D, which more exactly mimics the increase in both serum calcium and phosphorus, appeared in at least one periodically psychotic patient to trigger and opposite shift in CSF calcium. Moreover, in eight patients, manic symptomatology appeared de novo or grew significantly and substantially worse during 2 to 6 weeks of oral DHT administration. On the other hand, in 12 patients, subcutaneous injections of synthetic salmon calcitonin (SCT) decreased serum calcium and phosphorus, increased CSF calcium, and decreased agitation while augmenting depressive symptomatology. SCT also decreased quantified motor activity, frequency and severity of periodic agitated episodes, serum CPK and prolactin, and nocturnal sleep, while DHT or calcium lactate had opposite effects on the same parameters.

Calcium and electroconvulsive therapy of severe depressive illness.

In severely depressed patients with primary affective illness, consistent decreases in total calcium concentration have been demostrated in both CSF and serum following successful ECT treatment. The hypocalcemia does not appear to occur after the initial ECTs, but develops after three to five treatments, coincident with an acceleration in clinical antidepressant effects, and is not an artifact of the anesthetic premedications or mechanical ventilation of the patients. Evidence linking alterations in calcium metabolism to mood is reviewed and a number of mechanisms by which the calcium change might result from ECT and mediated its effects on mood are discussed.

CSF calcium: clinical correlates in affective illness and schizophrenia.

In a study of electrolytes in lumbar cerebrospinal fluid (csf) from psychiatric patients, the authors found a positive correlation between calcium concentration and symptom severity in hospitalized depressed patients. CSF calcium levels tended to decrease as patients improved. In four rapidly cycling patients, CSF calcium was higher during depression than during mania. Mean CSF calcium for the depressed patients as a group was not significantly different from neurological controls or other psychiatric patients. Symptom remission from acute psychosis in schizophrenic patients was accompanied by a significant increase in CSF calcium concentration. These findings are discussed in relationship to calcium-induced alterations in neuronal and physiological excitability.

Calcium: pacesetting the periodic psychoses.

In this double-blind study dihydrotachysterol (DHT) was given orally to eight psychotic patients; in each case marked increases in psychosis and agitation accompanied increases in serum calcium and phosphorus within two weeks after active drug was substituted for placebo. In the three patients whose psychoses exhibited periodic spontaneous exacerbations, the agitated episodes grew more severe. Serum creatine phosphokinase (CPK) increased in all but one patient. By contrast, when three periodically psychotic patients received synthetic salmon calcitonin (SCT), the severity and frequency of agitated episodes decreased while CSF calcium increased in all three. These data support the hypothesis that the observed abrupt increases in serum calcium and phosphorus might cause the opposite CSF calcium shifts, the behavioral agitation and the increases in serum CPK frequently noted during acute psychosis.

Negative effects of melatonin on depression.

In order to test the efficacy of the pineal neurohumor melatonin on depression, the hormone was administered in varying doses to six moderately to severely depressed patients and two patients with Huntington's chorea in double-blind crossover study. Melatonin exacerbated symptoms of dysphoria in these patients, as well as causing a loss of sleep and weight and a drop in oral temperature. Melatonin increased cerebrospinal fluid 5-hydroxyindoleacetic acid and calcium in three of four patients studied. The authors discuss the implications of this finding.

Wheat gluten challenge in schizophrenic patients.

Eight chronic schizophrenic patients were maintained on a diet free of gluten, cereal grains, and milk (CM-F diet) and challenged in a double-blind manner with dietary wheat gluten and placebo. While on the CM-F diet, each patient received a daily challenge of 30 g of gluten for 5 weeks and a placebo challenge for 8 weeks. No deterioration in clinical status as measured by the BPRS was noted on gluten challenge. Serum alpha 1 acid glycoprotein measurement demonstrated no evidence of inflammatory response to gluten challenge. The data suggest that sensitivity to dietary gluten is not characteristic of young chronic schizophrenic patients.

The cerebellofugal projections in the brachium conjunctivum of the rat I. The contralateral ascending pathway.

The cerebellofugal projections in the contralateral ascending pathway of the brachium conjunctivum (B.C.) in the rat have been investigated in 23 animals using the Fink-Heimer technique to demonstrate the axonal degeneration resulting from complete B.C. lesions (7), partial B.C. lesions (14) and control lesions dorsal to the B.C. (2). All of the degeneration resulting from the concomitant involvement of the structures surrounding the B.C. is accounted for in terms of known fiber pathways and from the results in the control experiments. The contralateral ascending pathway ascends rostrally from the decussation of the B.C. through the ventromedial midbrain tegmentum to the diencephalon. In the midbrain, cerebellofugal fibers terminate heavily throughout the red nucleus including the nucleus minimus, while others pass dorsolaterally and dorsomedially from the ascending tract to terminate in adjacent midbrain nuclei. The dorsolaterally directed fibers terminate in the midbrain reticular formation,the stratum griseum profundum of the superior colliculus, the anterior pretectalnucleus and the nucleus of the posterior commissure; the dorsomedially directed fibers terminate in the principal oculomotor nucleus, the nucleus of Darkschewitsch, interstitial nucleus of Cajal and the central gray matter. A considerable number of the cerebellofugal fibers proceed more rostrally within the prerubral field and enter the thalamus by two routes. Most follow a direct subthalamic course within field H of Fore1 and after contributing fibers to the zona incerta, enter the caudal pole of the ventromedial nucleus (Vm) of the thalamus to terminate throughout Vm and the ventrolateral complex (Vl). Others enter via the internal medullary lamina and terminate throughout the parafascicular and central lateral nuclei. A small number of cerebellothalamic fibers form a commissural projection to V1 on the opposite side.The finding that the cerebellothalamic projections to the ventral nucleus are distributed throughout Vm and V1 establishes the Vm-V1 complex as the homologue in the rat of the ventral anterior and ventral lateral nuclei in the primate thalamus.

Diet, prolactin, and breast cancer.

Relationships between dietary nutrients and plasma prolactin concentration were studied in 249 women with a history of nonskin cancers among first-degree female relatives. For each quintile of nutrient density, the odds ratio (OR), relative to the lowest quintile, of having an elevated (above the median) prolactin concentration was estimated by logistic regression, taking into account parity, menopausal status, and current tobacco-smoking habits. For nutrient densities estimated from 24-h recall data there was a significant positive association between plasma prolactin concentration and increasing saturated fatty acid intake; the OR of elevated prolactin in the top quintile was 3.1 [95% confidence interval (CI) 1.2-8.1] and there was a negative association with vitamin C [OR in the top quintile 0.28, (95% CI 0.10-0.78)]. For usual nutrient densities (estimated by quantitative food frequency questionnaire) there was a statistically significant trend (P = 0.04) toward lower prolactin concentrations with increasing sodium density, and a marginally significant positive trend (P = 0.07) with increasing dietary density of refined sugars.

Use of isolated immature-stage B cells to understand negative selection and tolerance induction at the molecular level.

Encounter with antigen by newly developing antigen receptor-positive B cells leads to negative selection. This process positions the B cell antigen receptor (BCR) in a central role for initiating the process of negative selection and suggests developmental regulation of its signaling. The observation that immature B cells are more susceptible to negative selection than are mature B cells has been demonstrated in a number of in vitro and in vivo model systems and support the idea of developmental regulation of BCR-initiated responses. Since identical antigen receptors are expressed on immature and mature B cells, the critical fate-determining distinction between these developmental stages must lie downstream of the receptor-ligand interaction itself, in the form of different BCR-linked signaling processes or with different secondary events occurring subsequent to BCR cross-linking. To address the first possibility, our laboratory and others have sought to define the differences in BCR-mediated signal transduction in immature and mature B lymphocytes. In this review article we will discuss current in vitro systems to study this question in primary, nontransformed murine B lymphocytes. In addition, we will discuss our previously published work in order to illustrate how these model systems have been useful in beginning to unravel the molecular basis for immune B cell negative selection and tolerance.

Epitope specificity of the bovine antibody response to the gIII glycoprotein of bovine herpesvirus type 1.

A panel of monoclonal antibodies (MAbs) to BHV-1, specific for gI and gIII glycoproteins and for a nonglycosylated core protein p100, was used to examine the epitope specificity of the immune response to the virus in naturally exposed and experimentally infected cattle. Sera from experimentally infected calves were analyzed in a competition ELISA (C-ELISA). Antibody to an epitope on gIII appeared as early as 4 days post infection, although virus-neutralizing antibody did not appear until day 8 or later. Antibody production peaked at 13 to 18 days post infection but the level of antibody to each gIII epitope varied. Competition by sera from cattle naturally exposed to BHV-1 was analyzed as a function of the virus neutralization (VN) titer of these sera. Competition with most of the MAbs correlated linearly with neutralization titer. However, competition with 2 of the MAbs, one specific for gIII and one specific for gI, was maximal even at the lowest neutralization titer, and competition with another MAb, specific for a non-glycosylated core protein, p100, was negative. Selected sera from the naturally exposed group were also examined by radioimmunprecipitation, and were shown to react predominantly with gI, gIII and gIV glycoproteins and in a few shown to react predominantly with gI, gIII and gIV glycoproteins and in a few MAbs were determined, and it was found that neutralization was enhanced by certain combinations. A mutually exclusive relationship between neutralization enhancement and competition for binding by MAbs (as determined by reciprocal C-ELISA) indicated an epitope-specific, rather than antibody-specific, mechanism for neutralization enhancement.

Lithium combined with neuroleptics in chronic schizophrenic and schizoaffective patients.

In a placebo-controlled double-blind crossover study lithium carbonate was added to the neuroleptic treatment of 11 chronic schizophrenic and 7 schizoaffective inpatients. Nurses' ratings of behavior indicated significant improvement in 8 patients in agitation or manic behavior, 5 patients in psychosis, and 5 patients in depression. A greater initial severity of symptoms, presence of affective symptoms and episodic course characterized the favorable response group. No neurotoxicity was encountered in this study.

A fixed-dose (300 mg) efficacy study of bupropion and placebo in depressed outpatients.

Two hundred twenty-four outpatients with major depression entered a 6-week, five-center, double-blind trial of bupropion 300 mg/day and placebo. A total of 216 patients were included in the efficacy analysis. In the combined center analysis, greater efficacy for bupropion was found on one or more measures (Hamilton Rating Scale for Depression, Montgomery-Asberg Depression Rating Scale, and Clinical Global Impressions) at treatment Days 21, 28, 35, and 42. Bupropion was well tolerated; only four adverse events were reported at least 5% more often in the bupropion group than in the placebo group. Six bupropion patients versus 5 placebo patients discontinued treatment because of adverse events. This study extends earlier findings of efficacy for higher-dose treatment in an inpatient population to lower-dose treatment in an outpatient population.

The EGR1 protein contains a discrete transcriptional regulatory domain whose deletion results in a truncated protein that blocks EGR1-induced transcription.

Egr-1 is a ubiquitous immediate-early gene whose expression is induced by a wide range of different stimuli. A requirement for egr-1 expression has been demonstrated in pathways leading to both proliferation and differentiation, suggesting that egr-1 is a critical intermediary in determining the long-term cellular response to a stimulus. To determine how egr-1 coordinates a cellular response to receptor-mediated stimulation, we have developed a transient cotransfection assay to map functional domains in the EGR1 protein. We localized an activation domain to a serine/threonine/proline-rich region between amino acids 174 and 270. Using this information, we designed a mutant that lacks this activation domain, but retains the DNA-binding domain. When cotransfected into fibroblasts with an EGR1-dependent reporter, this mutant inhibited the transcriptional activity of both endogenous EGR1, as well as exogenously expressed, wild-type EGR1 protein. These data demonstrate that the activation domain of EGR1 is critical for the activity of the protein, and that a mutant lacking this domain can dominantly inhibit wild-type EGR1 function.

Identification of Bacillus anthracis by API tests.

API and morphological tests were examined for their ability to distinguish between 37 Bacillus anthracis strains (virulent and avirulent) and 194 strains of closely related Bacillus species (B. cereus, B. mycoides and B. thuringiensis). In addition, 34 strains of B. anthracis and four of B. cereus were tested by several other methods that included capsule formation, ability to grow on a selective medium, and sensitivity to phage. It was found that virulent strains of B. anthracis were easily separated from the closely related Bacillus species by most of the test methods; but separation of slightly virulent and avirulent strains of B. anthracis from the closely related species could be done only by API and phage-sensitivity tests.