Defining sepsis on the wards: results of a multi-centre point-prevalence study comparing two sepsis definitions.

Our aim was to prospectively determine the predictive capabilities of SEPSIS-1 and SEPSIS-3 definitions in the emergency departments and general wards. Patients with National Early Warning Score (NEWS) of 3 or above and suspected or proven infection were enrolled over a 24-h period in 13 Welsh hospitals. The primary outcome measure was mortality within 30 days. Out of the 5422 patients screened, 431 fulfilled inclusion criteria and 380 (88%) were recruited. Using the SEPSIS-1 definition, 212 patients had sepsis. When using the SEPSIS-3 definitions with Sequential Organ Failure Assessment (SOFA) score ≥ 2, there were 272 septic patients, whereas with quickSOFA score ≥ 2, 50 patients were identified. For the prediction of primary outcome, SEPSIS-1 criteria had a sensitivity (95%CI) of 65% (54-75%) and specificity of 47% (41-53%); SEPSIS-3 criteria had a sensitivity of 86% (76-92%) and specificity of 32% (27-38%). SEPSIS-3 and SEPSIS-1 definitions were associated with a hazard ratio (95%CI) 2.7 (1.5-5.6) and 1.6 (1.3-2.5), respectively. Scoring system discrimination evaluated by receiver operating characteristic curves was highest for Sequential Organ Failure Assessment score (0.69 (95%CI 0.63-0.76)), followed by NEWS (0.58 (0.51-0.66)) (p < 0.001). Systemic inflammatory response syndrome criteria (0.55 (0.49-0.61)) and quickSOFA score (0.56 (0.49-0.64)) could not predict outcome. The SEPSIS-3 definition identified patients with the highest risk. Sequential Organ Failure Assessment score and NEWS were better predictors of poor outcome. The Sequential Organ Failure Assessment score appeared to be the best tool for identifying patients with high risk of death and sepsis-induced organ dysfunction.

Sexual selection in a hermaphroditic plant through female reproductive success.

Sexual selection is well accepted as a mechanism of shaping traits in animals. However, whether and how floral traits are sexually selected in hermaphroditic plants remains less clear. Here, we use Passiflora incarnata to address how floral traits that affect pollination success are selected via female function. We manipulated the ecological context by limiting pollination and adding resources to expand the phenotypic distribution and alter the intensity of sexual selection. Total sexual selection favoured lower style deflexion because of its impact on pollen receipt and subsequent seed number. However, total selection on style deflexion was not significant, indicating additional selection on style deflexion through routes other than mating. Limited pollination and enhanced resources were expected to alter the distribution of pollen deposition and seed production and therefore intensify the Bateman gradient - the relationship between pollen receipt and seed production. Indeed, the Bateman gradient was strongest when pollination was limited, suggesting potential for sexual selection to influence floral trait evolution under these conditions. Overall, we found floral traits may be shaped by sexual selection through female reproductive success in this hermaphroditic plant. These results support manipulations to enhance the variance in mating as a mechanism to understand patterns of sexual selection.

Reduced inbreeding depression in peripheral relative to central populations of a monocarpic herb.

Many temperate taxa were confined to warmer latitudes during the last glacial maximum. As their ranges expanded when climates warmed, genetic drift and inbreeding in relatively small peripheral populations are expected to have reduced genetic diversity and the segregating genetic load. Therefore, inbreeding depression in peripheral populations might be lower than in centrally located sites. We evaluated the consequences of inbreeding for fitness traits in six central and six northern peripheral populations of the herb Campanulastrum americanum. Inbreeding reduced performance for all traits. Inbreeding depression in peripheral populations was lower than in central populations. This difference increased across the life cycle from similar levels for germination, to central populations having three times the inbreeding depression for adult traits. Geographical patterns of inbreeding depression suggest that mating system variation and potential future mating system evolution in many temperate taxa might reflect, at least in part, nonequilibrium conditions associated with historic range changes.

The impact of a hybrid online and classroom-based course on palliative care competencies of family medicine residents.

The University of Calgary offers a palliative care course that involves both classroom- and web-based learning for rural-based family medicine residents. This study assessed the impact of the course on palliative care-related competencies for two classes: 2004 and 2005. Instruments were developed to evaluate pre- versus post-course changes in knowledge (15-item quiz), attitudes (12-item survey), self-perceived comfort levels (19-item survey) and skills (3 long Objective Structured Clinical Examination stations (OSCEs), with accompanying standardised score sheets). In all, 16 and 20 residents participated in the 2004 and 2005 classes, respectively. Internal reliability values were acceptable to very good (Knowledge Quiz, Kuder-Richardson 20 = 0.5; Attitude Scale, alpha = 0.68-0.78; OSCE score sheets, alpha = 0.63-0.89; Self-Perceived Comfort Survey, alpha = 0.89-0.92). Inter-rater reliability values of the OSCE score sheets were alpha = 0.87 to 0.92. There was a significant improvement in the pre- versus post-course performances in OSCE 2 for 2004 and 2005 (P = 0.01; P = 0.01; d = 1.42 and 1.94, respectively). Despite statistically insignificant changes in the other OSCEs, acceptable to large effect sizes were noted (d = 0.4-1.34) for OSCE 1 in 2004 and OSCEs 3 in 2004 and 2005. Knowledge improved significantly pre-versus post-course in 2004 and 2005 (t = 4.44 and 8.99; d = 2.29 and 2.24, respectively). Significant improvements and large effect sizes were noted in the comfort scales, but a ceiling effect was noted in the communication subscale. This hybrid course resulted in significant improvements across four domains, knowledge, attitudes, self-perceived comfort scale, and skills, in 2 consecutive classes.

Detection of Streptococcus pneumoniae colonisation in respiratory tract secretions of military personnel.

Respiratory tract infections with Streptococcus pneumoniae are an important cause of morbidity and mortality among military personnel. A sensitive method is needed to determine the prevalence of S. pneumoniae colonisation in respiratory secretions, as well as its role in pneumonia without an established aetiology. This study investigated the efficacy of two PCR assays in screening military personnel for S. pneumoniae colonisation. Nasopharyngeal swabs were obtained from 200 military personnel and tested for S. pneumoniae by culture and PCR. S. pneumoniae was cultured from three (1.5%) of the 200 samples. PCR for the lytA gene detected S. pneumoniae in 11% of the samples, while PCR for the pneumolysin gene detected S. pneumoniae in 3% of the samples. The sensitivity and negative predictive values were 100% for both PCR assays when compared to culture; the specificity and positive predictive values for the lytA PCR were 90.4% and 13.6%, respectively, compared with 98.5% and 50%, respectively, for the pneumolysin gene PCR. It was concluded that respiratory tract colonisation of military personnel with S. pneumoniae can be identified rapidly and reliably by PCR assays. The use of this technique may greatly enhance the ability to identify a microbial aetiology for pneumonia when compared with conventional culture methods.

Chronic activation of protein kinase C in soleus muscles and other tissues of insulin-resistant type II diabetic Goto-Kakizaki (GK), obese/aged, and obese/Zucker rats. A mechanism for inhibiting glycogen synthesis.

We examined the possibility that protein kinase C (PKC) is chronically activated and may contribute to impaired glycogen synthesis and insulin resistance in soleus muscles of hyperinsulinemic type II diabetic Goto-Kakizaki (GK) rats. Relative to nondiabetic controls, PKC enzyme activity and levels of immunoreactive PKC-alpha, beta, epsilon, and delta were increased in membrane fractions and decreased cytosolic fractions of GK soleus muscles. In addition, PKC-theta levels were decreased in both membrane and cytosol fractios, whereas PKC-zeta levels were not changed in either fraction in GK soleus muscles. These increases in membrane PKC (alpha, beta, epsilon, and delta) could not be accounted for by alterations in PKC mRNA or total PKC levels but were associated with increases in membrane diacylglycerol (DAG) and therefore appeared to reflect translocative activation of PKC. In evaluation of potential causes for persistent PKC activation, membrane PKC levels were decreased in soleus muscles of hyperglycemic streptozotocin (STZ)-induced diabetic rats; thus, a role for simple hyperglycemia as a cause of PKC activation in GK rats was not evident in the STZ model. In support of the possibility that hyperinsulinemia contributed to PKC activation in GK soleus muscles, we found that DAG levels were increased, and PKC was translocated, in soleus muscles of both (1) normoglycemic hyperinsulinemic obese/aged rats and (2) mildly hyperglycemic hyperinsulinemic obese/Zucker rats. In keeping with the possibility that PKC activation may contribute to impaired glycogen synthase activation in GK muscles, phorbol esters inhibited, and a PKC inhibitor, RO 31-8220, increased insulin effects on glycogen synthesis in soleus muscles incubated in vitro. Our findings suggested that: (1) hyperinsulinemia, as observed in type II diabetic GK rats and certain genetic and nongenetic forms of obesity in rats, is associated with persistent translocation and activation of PKC in soleus muscles, and (2) this persistent PKC activation may contribute to impaired glycogen synthesis and insulin resistance.

Insulin translocates PKC-epsilon and phorbol esters induce and persistently translocate PKC-beta 2 in BC3H-1 myocytes.

Initial studies suggested that insulin increases diacylglycerol and activates protein kinase C (PKC) in BC3H-1 myocytes. In these earlier studies, insulin was found to translocate PKC-beta, but the presence of PKC-epsilon was not appreciated. More recently, the presence of PKC-epsilon was documented, but PKC-beta was not detected, and it was questioned whether insulin activates PKC in BC3H-1 myocytes [Stumpo, D.J., Haupt, D.M. and Blackshear, P.J. (1994) J. Biol. Chem. 269:21184-21190]. We questioned whether insulin translocates PKC-epsilon in BC3H-1 myocytes, and re-evaluated the question of whether myocytes truly contain a PKC-beta isoform whose existence can be verified by its response to phorbol ester treatment. We found that PKC-epsilon was acutely translocated by insulin and phorbol esters from the cytosol to the membrane fraction in BC3H-1 myocytes; in addition, PKC-epsilon, like PKC-alpha, was depleted by chronic phorbol ester treatment. We also found that BC3H-1 myocytes containing a 76,000 Mr PKC-beta isoform that is acutely translocated and subsequently depleted by phorbol esters. Moreover, chronic phorbol ester treatment induced an 84,000 Mr PKC-beta 2 isoform that appeared to be persistently translocated and activated, as suggested by studies of myristoylated arginic-rich C kinase substrate (MARCKS) phosphorylation. We conclude that: (1) insulin acutely translocates PKC-epsilon, as well as PKC-beta, in BC3H-1 myocytes; and (2) PKC-beta is not truly downregulated by phorbol esters in BC3H-1 myocytes.

Evidence for involvement of protein kinase C (PKC)-zeta and noninvolvement of diacylglycerol-sensitive PKCs in insulin-stimulated glucose transport in L6 myotubes.

We examined the question of whether insulin activates protein kinase C (PKC)-zeta in L6 myotubes, and the dependence of this activation on phosphatidylinositol (PI) 3-kinase. We also evaluated a number of issues that are relevant to the question of whether diacylglycerol (DAG)-dependent PKCs or DAG-insensitive PKCs, such as PKC-zeta, are more likely to play a role in insulin-stimulated glucose transport in L6 myotubes and other insulin-sensitive cell types. We found that insulin increased the enzyme activity of immunoprecipitable PKC-zeta in L6 myotubes, and this effect was blocked by PI 3-kinase inhibitors, wortmannin and LY294002; this suggested that PKC-zeta operates downstream of PI 3-kinase during insulin action. We also found that treatment of L6 myotubes with 5 microM tetradecanoyl phorbol-13-acetate (TPA) for 24 h led to 80-100% losses of all DAG-dependent PKCs (alpha, beta1, beta2, delta, epsilon) and TPA-stimulated glucose transport (2-deoxyglucose uptake); in contrast, there was full retention of PKC-zeta, as well as insulin-stimulated glucose transport and translocation of GLUT4 and GLUT1 to the plasma membrane. Unlike what has been reported in BC3H-1 myocytes, TPA treatment did not elicit increases in PKCbeta2 messenger RNA or protein in L6 myotubes, and selective retention of this PKC isoform could not explain the retention of insulin effects on glucose transport after prolonged TPA treatment. Of further interest, TPA acutely activated membrane-associated PI 3-kinase in L6 myotubes, and acute effects of TPA on glucose transport were inhibited, not only by the PKC inhibitor, LY379196, but also by both wortmannin and LY294002; this suggested that DAG-sensitive PKCs activate glucose transport through cross-talk with phosphatidylinositol (PI) 3-kinase, rather than directly through PKC. Also, the cell-permeable, myristoylated PKC-zeta pseudosubstrate inhibited insulin-stimulated glucose transport both in non-down-regulated and PKC-depleted (TPA-treated) L6 myotubes; thus, the PKC-zeta pseudosubstrate appeared to inhibit a protein kinase that is required for insulin-stimulated glucose transport but is distinct from DAG-sensitive PKCs. In keeping with the latter dissociation of DAG-sensitive PKCs and insulin-stimulated glucose transport, LY379196, which inhibits PKC-beta (preferentially) and other DAG-sensitive PKCs at relatively low concentrations, inhibited insulin-stimulated glucose transport only at much higher concentrations, not only in L6 myotubes, but also in rat adipocytes, BC3H-1 myocytes, 3T3/L1 adipocytes and rat soleus muscles. Finally, stable and transient expression of a kinase-inactive PKC-zeta inhibited basal and insulin-stimulated glucose transport in L6 myotubes. Collectively, our findings suggest that, whereas PKC-zeta is a reasonable candidate to participate in insulin stimulation of glucose transport, DAG-sensitive PKCs are unlikely participants.

Insulin stimulates phospholipase D-dependent phosphatidylcholine hydrolysis, Rho translocation, de novo phospholipid synthesis, and diacylglycerol/protein kinase C signaling in L6 myotubes.

Previous studies have provided conflicting findings on whether insulin activates certain, potentially important, phospholipid signaling systems in skeletal muscle preparations. In particular, insulin effects on the hydrolysis of phosphatidylcholine (PC) and subsequent activation of protein kinase C (PKC) have not been apparent in some studies. Presently, we examined insulin effects on phospholipid signaling systems, diacylglycerol (DAG) production, and PKC translocation/activation in L6 myotubes. We found that insulin provoked rapid increases in phospholipase D (PLD)-dependent hydrolysis of PC, as evidenced by increases in choline release and phosphatidylethanol production in cells incubated in the presence of ethanol. In association with PC-PLD activation, Rho, a small G protein that is known to activate PC-PLD activation, translocated from the cytosol to the membrane fraction in response to insulin treatment. PC-PLD activation was also accompanied by increases in total DAG production and increases in the translocation of both PKC enzyme activity and DAG-sensitive PKC-alpha, -beta, -delta, and -epsilon from the cytosol to the membrane fraction. A potential role for PKC or a related protein kinase in insulin action was suggested by the finding that RO 31-8220 inhibited both PKC enzyme activity and insulin-stimulated [3H]2-deoxyglucose uptake. Our findings provide the first evidence that insulin stimulates Rho translocation and activates PC-PLD in L6 skeletal muscle cells. Moreover, this signaling system appears to lead to increases in DAG/PKC signaling, which, along with other related signaling factors, may regulate certain metabolic processes, such as glucose transport, in these cells.

Effects of knockout of the protein kinase C beta gene on glucose transport and glucose homeostasis.

The beta-isoform of protein kinase C (PKC) has paradoxically been suggested to be important for both insulin action and insulin resistance as well as for contributing to the pathogenesis of diabetic complications. Presently, we evaluated the effects of knockout of the PKCbeta gene on overall glucose homeostasis and insulin regulation of glucose transport. To evaluate subtle differences in glucose homeostasis in vivo, knockout mice were extensively backcrossed in C57BL/6 mice to diminish genetic differences other than the absence of the PKCbeta gene. PKCbeta-/- knockout offspring obtained through this backcrossing had 10% lower blood glucose levels than those observed in PKCbeta+/+ wild-type offspring in both the fasting state and 30 min after i.p. injection of glucose despite having similar or slightly lower serum insulin levels. Also, compared with commercially obtained C57BL/6-129/SV hybrid control mice, serum glucose levels were similar, and serum insulin levels were similar or slightly lower, in C57BL/6-129/SV hybrid PKCbeta knockout mice in fasting and fed states and after i.p. glucose administration. In keeping with a tendency for slightly lower serum glucose and/or insulin levels in PKCbeta knockout mice, insulin-stimulated 2-deoxyglucose (2-DOG) uptake was enhanced by 50-100% in isolated adipocytes; basal and insulin-stimulated epitope-tagged GLUT4 translocations in adipocytes were increased by 41% and 27%, respectively; and basal 2-DOG uptake was mildly increased by 20-25% in soleus muscles incubated in vitro. The reason for increased 2-DOG uptake and/or GLUT4 translocation in these tissues was uncertain, as there were no significant alterations in phosphatidylinositol 3-kinase activity or activation or in levels of GLUT1 or GLUT4 glucose transporters or other PKC isoforms. On the other hand, increases in 2-DOG uptake may have been partly caused by the loss of PKCbeta1, rather than PKCbeta2, as transient expression of PKCbeta1 selectively inhibited insulin-stimulated translocation of epitope-tagged GLUT4 in adipocytes prepared from PKCbeta knockout mice. Our findings suggest that 1) PKCbeta is not required for insulin-stimulated glucose transport; 2) overall glucose homeostasis in vivo is mildly enhanced by knockout of the PKCbeta gene; 3) glucose transport is increased in some tissues in PKCbeta knockout mice; and 4) increased glucose transport may be partly due to loss of PKCbeta1, which negatively modulates insulin-stimulated GLUT4 translocation.

Effects of phorbol esters on insulin-induced activation of phosphatidylinositol 3-kinase, glucose transport, and glycogen synthase in rat adipocytes.

In rat adipocytes, phorbol ester-induced activation of PKC did not inhibit insulin signalling through IRS-1-dependent phosphatidylinositol (PI) 3-kinase activation. Moreover, phorbol esters alone provoked an increase in membrane PI 3-kinase activity. These findings may be relevant to the failure of phorbol esters to inhibit insulin effects on glucose transport and glycogen synthesis in rat adipocytes.

Population differentiation in an annual legume: genetic architecture.

The presence or absence of epistasis, or gene interaction, is explicitly assumed in many evolutionary models. Although many empirical studies have documented a role of epistasis in population divergence under laboratory conditions, there have been very few attempts at quantifying epistasis in the native environment where natural selection is expected to act. In addition, we have little understanding of the frequency with which epistasis contributes to the evolution of natural populations. In this study we used a quantitative genetic design to quantify the contribution of epistasis to population divergence for fitness components of a native annual legume, Chamaecrista fasciculata. The design incorporated the contrast of performance of F2 and F3 segregating progeny of 18 interpopulation crosses with the F1 and their parents. Crosses were conducted between populations from 100 m to 2000 km apart. All generations were grown for two seasons in the natural environment of one of the parents. The F1 often outperformed the parents. This F1 heterosis reveals population structure and suggests that drift is a major contributor to population differentiation. The F2 generation demonstrated that combining genes from different populations can sometimes have unexpected positive effects. However, the F3 performance indicated that combining genes from different populations decreased vigor beyond that due to the expected loss of heterozygosity. Combined with previous data, our results suggest that both selection and drift contribute to population differentiation that is based on epistatic genetic divergence. Because only the F3 consistently expressed hybrid breakdown, we conclude that the epistasis documented in our study reflects interactions among linked loci.

Population differentiation in an annual legume: local adaptation.

Studies of many plants species have demonstrated adaptive genetic differentiation to local environmental conditions. Typically these studies are conducted to evaluate adaptation to contrasting environments. As a consequence, although local adaptation has been frequently demonstrated, we have little information as to the spatial scale of adaptive evolution. We evaluated adaptive differentiation between populations of the annual legume Chamaecrista fasciculata using a replicated common-garden design. Study sites were established in three field locations that are home to native populations of C. fasciculata. Each location was planted for two years with seed from the population native to the study site (home population) and populations located six distances (0.1-2000 km) from each site (transplanted populations). Seeds were planted into the study sites with minimum disturbance to determine the scale of local adaptation, as measured by a home-site fitness advantage, for five fitness components: germination, survival, vegetative biomass, fruit production, and the number of fruit produced per seed planted (an estimate of cumulative fitness). For all characters there was little evidence for local adaptation, except at the furthest spatial scales. Patterns of adaptive differentiation were fairly consistent in two of the three sites, but varied between years. Little genetic variation was expressed at the third site. These results, combined with previous estimates of limited gene flow, suggest that metapopulation processes and temporal environmental variation act together to reduce local adaptation, except over long distances.

Nuclear and cytoplasmic contributions to intraspecific divergence in an annual legume.

The genetic architecture of trait differentiation was evaluated between two ecologically distinct populations of Chamaecrista fasciculata. Individuals from Maryland and Illinois populations were crossed to create 10 types of seed: Maryland and Illinois parents, reciprocal F1 and F2 hybrids, and backcrosses to Maryland and to Illinois on reciprocal F1 hybrids. Reciprocal crosses created hybrid generation seeds with both Maryland and Illinois cytoplasmic backgrounds. Experimental individuals were grown in a common garden near the site of the Maryland population. In the garden, plants from the Illinois population flowered, set fruit, and died earlier than those from Maryland, likely reflecting adaptations to differences in growing season length between the two populations. Although reproductive components at the flower and whole plant level differed between the two populations, reproductive output as measured by fruit and seed production was similar. Cytoplasmic genes had a subtle but pervasive effect on population differentiation; hybrids with Maryland cytoplasm were significantly differentiated from those with Illinois cytoplasm when all characters were evaluated jointly. The nuclear genetic architecture of population differentiation was evaluated with joint scaling tests. Depending on the trait, both additive and nonadditive genetic effects contributed to population differentiation. Intraspecific genetic differentiation in this wild plant species appears to reflect a complex genetic architecture that includes the contribution of additive, dominance, and epistatic components in addition to subtle cytoplasmic effects.

Reduced branching and length of dendrites detected in cervical spinal cord motoneurons of Wobbler mouse, a model for inherited motoneuron disease.

The Wobbler mouse (wr) has been proposed as a model for human inherited motoneuron disease (infantile spinal muscular atrophy). The primary defect is thought to be in the motoneurons. Therefore we undertook a survey of the qualitative and quantitative changes occurring in the cervical spinal motoneurons of Wobbler mice during a late stage of the motoneuron disease compared with age- and sex-matched normal phenotype (NFR/wr) littermates. The Rapid Golgi Method was applied. In control and Wobbler mice, four types of neurons were identified according to their dendritic patterns: multipolar, tripolar, bipolar, and unipolar cells. Unipolar cells were observed more often in the Wobbler specimens than the controls and may represent a final stage in the degeneration of other cell types with greater numbers of primary dendrites. Medium (300-999 microns 2) and large (greater than 1,000 microns 2) impregnated neurons (presumably alpha-motoneurons) showed strong indications of cell degeneration, including statistically significant reductions in the measurements for dendritic length, distribution, and branching, as well as the number of spines. In contrast, the small (less than 300 microns 2) neurons showed only mild signs of degeneration, including slight reductions in dendritic length, but no significant differences appeared in the distribution and branching of dendrites, or in the number of spines. Instead, a small increase could be detected in the number of primary and secondary dendritic branches emanating from the small neurons, as well as in the number of dendritic spines. These findings suggest that sprouting may occur to a slight extent. Although previous studies document that swelling with subsequent vacuolation of motoneurons is the predominant feature characterizing the Wobbler disease, the mean soma area (microns 2) calculated for the impregnated neurons of the Wobbler specimens showed no significant difference from the controls. It is hypothesized that the advanced signs of the Wobbler motoneuron disease are primarily reflected in the degeneration of the dendrites and spines on the medium and large alpha-motoneurons. The small neurons (presumably a mixed population of gamma-motoneurons, interneurons, and Renshaw cells) possess dendrites and spines that seem to be less affected, and instead show signs of sprouting.

Alteration in the levels of thyrotropin releasing hormone, substance P and enkephalins in the spinal cord, brainstem, hypothalamus and midbrain of the Wobbler mouse at different stages of the motoneuron disease.

The present study was undertaken to quantify selected neuropeptides (thyrotropin releasing hormone, substance P, methionine and leucine enkephalin) in the cervical spinal cord and other regions of the central nervous system of Wobbler mice by radioimmunoassays during several stages of the motoneuron disease compared with age- and sex-matched normal phenotype littermates. In Wobbler spinal cord, thyrotropin releasing hormone is higher early in the disease, whereas in the brainstem it is higher at a later stage. Substance P in spinal cord is also higher late in the disease. Leucine enkephalin levels are greater at all stages in diseased spinal cord and brainstem, but methionine enkephalin increases only late in the disease. Highly significant increases of the peptides (except thyrotropin releasing hormone) appear in hypothalamus and midbrain only late in the motoneuron disease. Regression analyses show that thyrotropin releasing hormone in spinal cord and brainstem decreases normally with age in the control mice and at a faster rate related to the extent of motor impairment in Wobbler mice. Thyrotropin releasing hormone and methionine enkephalin in the Wobbler brainstem correlate (P less than 0.05) with the progress of the motoneuron disease. Methionine enkephalin increases faster in Wobbler brainstem and decreases faster in control spinal cord with age. The increase of leucine enkephalin in the Wobbler spinal cord correlates significantly with age and with the progress of the disease, but leucine enkephalin declines slightly with age in the controls. The changes of substance P in spinal cord and brainstem do not correlate significantly with the progress of the disease. In the hypothalamus, increasing values for substance P in control specimens and enkephalins in Wobbler specimens are significantly correlated with age. However, in the midbrain, higher methionine and leucine enkephalin levels are significantly associated with age only in the control mice. Alterations of neuropeptides in the Wobbler mouse spinal cord and brainstem may result from the degeneration of bulbospinal raphe neurons projecting to the ventral spinal cord, or from primary afferent or interneuronal nerve terminals. The data imply that the neuronal degeneration process in the Wobbler motoneuron disease is not limited to motoneurons. In the spinal cord, the data support our previous hypothesis that neuronal sprouting presynaptic to the motoneurons may account for increased neuropeptide concentrations. Alternatively, synthesis and/or degradation of these peptides may be altered. In addition, it is proposed that enkephalinergic neurons may develop abnormally in Wobbler mice. The early increase of leucine enkephalin in the Wobbler spinal cord possibly indicates its importance in the etiology of the motoneuron disease.

Bupropion in the long-term treatment of cyclic mood disorders: mood stabilizing effects.

The effects of bupropion HCl in treating 11 patients with bipolar or schizoaffective disorder were examined in an open trial. Most patients had been intolerant of or showed minimal to moderate improvement on lithium, neuroleptics, antidepressants, or a combination of these drugs. All patients were maintained on bupropion alone or bupropion in combination with low-dose neuroleptics or anxiolytics for 1 year or more, with little or no relapse and few side effects.

Spiny interneurons identified in the normal mouse spinal cord show alterations in the Wobbler mouse: a model for inherited motoneuron disease.

Presumed interneurons are described in the Golgi-impregnated cervical spinal cord taken from normal phenotype and motoneuron-diseased mice of the Wobbler mouse strain (NFR/wr), as well as from the spinal cord of two related normal mouse strains (C57B1/6N and NFR/N). The interneurons, distributed throughout Rexed's laminae V-VIII, are characterized by numerous spines clustered along the distal dendrites. Quantitatively, the soma size (µm2) of the interneurons in the Wobbler specimens studied late in the motoneuron disease is smaller than that measured in the pair-matched (3-week-old) normal phenotype littermates. Early in the disease, the spine density (number of spines per 100 µm length dendrite) is greater compared with the normal phenotype littermates, perhaps implying that sprouting may occur. At a later stage in the disease process, the spine density does not differ significantly. However the increase in the spine density expected with advancing age is not observed for the Wobbler interneurons. It is proposed that perhaps the normal age-related proliferation of spines is impaired in the Wobbler mice. Since the measurements for spine length are lower in the Wobbler interneurons studied late in the motoneuron disease compared with the pair-matched (3-month-old) normal phenotype littermates, the normal age-related lengthening of the spines seems to be lacking. In addition, the spine length measured in the normal phenotype littermates is significantly greater compared with the normal mice (NFR/N, C57B1/6N). Thus the growth patterns of the spines may differ in the Wobbler mouse strain compared with the normal (C57B1/6N, NFR/N) mouse strains. It is proposed that the Wobbler motoneuron disease affects interneurons as well as motoneurons.

Alterations of immunoreactive substance P and enkephalins in rat spinal cord after electroacupuncture.

A form of electrically-induced analgesia known as electroacupuncture was administered to rats bilaterally at the point "Huan-tiao." Compared with untreated rats, treated rats showed altered pain thresholds characterized as low, intermediate, and high. From immunocytochemical studies, the spinal cords taken from the treated rats exhibited differences in immunoreactivity for substance P (SP), methionine- and leucine-enkephalins (ME and LE respectively). By densitometry, the altered levels of immunoreactive (IR) peptides correlated with the pain thresholds in specific ways. That is, high pain threshold correlated with the visualization of increased IR-SP adn IR-LE within neuronal processes throughout the dorsal horn substantia gelatinosa. In the same specimens, decreased IR-ME could be seen. In contrast, low pain threshold correlated with decreased IR-SP and IR-ME. IR-LE showed a concomitant decrease in the medial substantia gelatinosa region, and slight, insignificant changes laterally. The data suggest that different degrees of analgesia induced by electroacupuncture result from the variable release of SP, ME, and LE in spinal regions associated with nociception. In terms of current models of pain processing, the data do not entirely support an axo-axonic interaction between enkephalin interneurons and SP terminals. Some modifications and an alternative model are considered.

Identification of thyrotropin-releasing hormone receptor mRNA in the Leydig cells of the mouse testis by in situ hybridization.

Thyrotropin-releasing hormone receptor (TRH-R) mRNA was detected in cryostat sections of the mouse testis using biotinylated oligonucleotides complementary to the cDNA encoding the mouse pituitary TRH-R by in situ hybridization. Hybridization signals were detected exclusively in the Leydig cells. The intensity of the signal was probe-concentration dependent. This result suggests that testicular TRH may serve as an autocrine regulator of reproductive function and development via TRH-R in a fashion that is similar or identical to that in the pituitary.