Evidence for a stimulatory action of melanin-concentrating hormone on luteinising hormone release involving MCH1 and melanocortin-5 receptors.

The present series of studies aimed to further our understanding of the role of melanin-concentrating hormone (MCH) neurones in the central regulation of luteinising hormone (LH) release in the female rat. LH release was stimulated when MCH was injected bilaterally into the rostral preoptic area (rPOA) or medial preoptic area (mPOA), but not when injected into the zona incerta (ZI), of oestrogen-primed ovariectomised rats. In rats that were steroid-primed to generate a surge-like release of LH, MCH administration into the ZI blocked this rise in LH release: no such effect occurred when MCH was injected into the rPOA or mPOA. In vitro, MCH stimulated gonadotrophin-releasing hormone (GnRH) release from hypothalamic explants. Double-label immunohistochemistry showed GnRH-immunoreactive neurones in the vicinity of and intermingled with immunoreactive MCH processes. MCH is the endogenous ligand of the MCH type 1 receptor (MCH1-R). Previously, we have shown a role for melanocortin-5 receptors (MC5-R) in the stimulatory action of MCH, so we next investigated the involvement of both MCH1-R and/or MC5-R in mediating the actions of MCH on GnRH and hence LH release. The stimulatory action of MCH in the rPOA was inhibited by administration of antagonists for either MCH1-R or MC5-R. However, in the mPOA, the action of MCH was blocked only by the MC5-R antagonist. LH release was stimulated by an agonist for MC5-R injected into the rPOA or mPOA; this was blocked by the MC5-R antagonist but not the MCH1-R antagonist. These results indicate that both MCH1-R and MC5-R are involved in the central control of LH release by MCH.

The dorsal cyst in holoprosencephaly and the role of the thalamus in its formation.

The dorsal cyst is poorly understood, although it is commonly encountered in holoprosencephaly. We endeavor to establish the role of diencephalic malformations in the formation of the dorsal cyst and speculate on the developmental factors responsible. We reviewed the imaging of 70 patients with holoprosencephaly (MRI of 50 and high-quality CT of 20). The presence or absence of a dorsal cyst, thalamic noncleavage and abnormal thalamic orientation were assessed for statistical association, using Fisher's Exact Test and logistical regression. The presence of a dorsal cyst correlated strongly with the presence of noncleavage of the thalamus (P = 0.0007) and with its degree (P < 0.00005). There was a trend toward an association between abnormalities in the orientation of the thalamus and the dorsal cyst, but this was not statistically significant (P = 0.07). We speculate that the unseparated thalamus physically blocks egress of cerebrospinal fluid from the third ventricle, resulting in expansion of the posterodorsal portion of the ventricle to form the cyst.

Characterization of the zinc sites in cobalamin-independent and cobalamin-dependent methionine synthase using zinc and selenium X-ray absorption spectroscopy.

X-ray absorption spectroscopy has been used to investigate binding of selenohomocysteine to cobalamin-independent (MetE) and cobalamin-dependent (MetH) methionine synthase enzymes of Escherichia coli. We have shown previously [Peariso et al. (1998) J. Am. Chem. Soc. 120, 8410-8416] that the Zn sites in both enzymes show an increase in the number of sulfur ligands when homocysteine binds. The present data provide direct evidence that this change is due to coordination of the substrate to the Zn. Addition of L-selenohomocysteine to either MetE or the N-terminal fragment of MetH, MetH(2-649), causes changes in the zinc X-ray absorption near-edge structure that are remarkably similar to those observed following the addition of L-homocysteine. Zinc EXAFS spectra show that the addition of L-selenohomocysteine changes the coordination environment of the zinc in MetE from 2S + 2(N/O) to 2S + 1(N/O) + 1Se and in MetH(2-649) from 3S + 1(N/O) to 3S + 1Se. The Zn-S, Zn-Se, and Se-S bond distances determined from the zinc and selenium EXAFS data indicate that the zinc sites in substrate-bound MetE and MetH(2-649) both have an approximately tetrahedral geometry. The selenium edge energy for selenohomocysteine shifts to higher energy when binding to either methionine synthase enzyme, suggesting that there is a slight decrease in the effective charge of the selenium. Increases in the Zn-Cys bond distances upon selenohomocysteine binding together with identical magnitudes of the shifts to higher energy in the Se XANES spectra of MetE and MetH(2-649) suggest that the Lewis acidity of the Zn sites in these enzymes appears the same to the substrate and is electronically buffered by the Zn-Cys interaction.

Adhesion induced expression of the serine/threonine kinase Fnk in human macrophages.

Members of the polo subfamily of protein kinases play crucial roles in cell proliferation. To study the function of this family in more detail, we isolated the cDNA of human Fnk (FGF-inducible kinase) which codes for a serine/threonine kinase of 646 aa. Despite the homology to the proliferation-associated polo-like kinase (Plk), tissue distribution of Fnk transcripts and expression kinetics differed clearly. In contrast to Plk no correlation between cell proliferation and Fnk gene expression was found. Instead high levels of Fnk mRNA were detectable in blood cells undergoing adhesion. The transition of monocytes from peripheral blood to matrix bound macrophages was accompanied by increasing levels of Fnk with time in culture. Neither treatment of monocytes with inducers of differentiation nor withdrawal of serum did influence Fnk mRNA levels significantly, suggesting that cell attachment triggers the onset of Fnk gene transcription. The idea that Fnk is part of the signalling network controlling cellular adhesion was supported by the analysis of the cytoplasmic distribution of the Fnk protein and the influence of its overexpression on the cellular architecture. Fnk as fusion protein with GFP localized at the cellular membrane in COS cells. Dysregulated Fnk gene expression disrupted the cellular f-actin network and induced a spherical morphology. Furthermore, Fnk binds to the Ca2+/integrin-binding protein Cib in two-hybrid-analyses and co-immunoprecipitation in assays. Moreover, both proteins were shown to co-localize in mammalian cells. The homology of Cib with calmodulin and with calcineurin B suggests that Cib might be a regulatory subunit of polo-like kinases.

Anticonvulsant compounds from the wood of Caesalpinia sappan L.

80% Aqueous MeOH extracts from the wood of Caesalpinia sappan, which showed remarkable anticonvulsant activity, were fractionated using EtOAc, n-BuOH, and H2O. Among them, the EtOAc fraction significantly inhibited the activities of two GABA degradative enzymes, succinic semialdehyde dehydrogenase (SSADH) and succinic semialdehyde reductase (SSAR). Repeated column chromatographies for the fraction guided by activity test led to the isolation of the two active principal components. Their chemical structures were determined to be sappanchalcone and brazilin based on spectral data. The pure compounds, sappanchalcone (1) and brazilin (2), inactivated the SSAR activities in a dose dependent manner, whereas SSADH was inhibited partially by sappanchalcone and not by brazilin.

Effect of ginsenosides, active components of ginseng, on capsaicin-induced pain-related behavior.

Our recent study demonstrated that ginsenosides had antinociceptive effects by reducing some types of pain-related behavior in mice (Yoon et al., 1998. Ginsenosides induce differential antinociception and inhibit substance P-induced nociceptive response in mice. Life Science 62, PL319-PL325). In the present study we further investigated whether ginsenosides produce antinociceptive effects through an action at central or peripheral site(s) and whether these effects are mediated by the opioid system. Intraperitoneally injected ginsenosides suppressed in a dose-dependent manner the pain-related behavior produced by capsaicin injection into the plantar surface of the hind paw; the ED(50) was 49 mg/kg [26-92 mg/kg, 95% confidence interval (C.I.)]. Intrathecally or intracerebroventricularly administered ginsenosides also suppressed the capsaicin-induced pain-related behavior in a dose-dependent manner; the ED(50)s were 1.72 mg/kg (0.8-3.72 mg/kg, 95% C.I.) and 1. 48 mg/kg (0.8-2.6 mg/kg, 95% C.I.), respectively. On the other hand, subcutaneously injected ginsenosides to the plantar surface prior to the capsaicin injection did not alter the pain-related behavior. Naloxone pretreatment was without effect in blocking the antinociceptive effect of intrathecally administered ginsenosides. Intraperitoneally injected ginsenosides also did not significantly affect the motor response of animals. These results suggest that ginsenosides produce antinociceptive effects through their action at the spinal and/or supraspinal site(s), not at nociceptors in the periphery. In addition, the results suggest that the antinociceptive effects are not mediated by opioid receptors.

Constitutive activation of extracellular signal-regulated kinase in human acute leukemias: combined role of activation of MEK, hyperexpression of extracellular signal-regulated kinase, and downregulation of a phosphatase, PAC1.

Extracellular signal-regulated kinase (ERK) is an important intermediate in signal transduction pathways that are initiated by many types of cell surface receptors. It is thought to play a pivotal role in integrating and transmitting transmembrane signals required for growth and differentiation. Constitutive activation of ERK in fibroblasts elicits oncogenic transformation, and recently, constitutive activation of ERK has been observed in some human malignancies, including acute leukemia. However, mechanisms underlying constitutive activation of ERK have not been well characterized. In this study, we examined the activation of ERK in 79 human acute leukemia samples and attempted to find factors contributing to constitutive ERK activation. First, we showed that ERK and MEK were constitutively activated in acute leukemias by in vitro kinase assay and immunoblot analysis. However, in only one half of the studied samples, the pattern of ERK activation was similar to that of MEK activation. Next, by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblot analysis, we showed hyperexpression of ERK in a majority of acute leukemias. In 17 of 26 cases (65.4%) analyzed by immunoblot, the pattern of ERK expression was similar to that of ERK activation. The fact of constitutive activation of ERK in acute leukemias suggested to us the possibility of an abnormal downregulation mechanism of ERK. Therefore, we examined PAC1, a specific ERK phosphatase predominantly expressed in hematopoietic tissue and known to be upregulated at the transcription level in response to ERK activation. Interestingly, in our study, PAC1 gene expression in acute leukemias showing constitutive ERK activation was significantly lower than that in unstimulated, normal bone marrow (BM) samples showing minimal or no ERK activation (P =.002). Also, a significant correlation was observed between PAC1 downregulation and phosphorylation of ERK in acute leukemias (P =.002). Finally, by further analysis of 26 cases, we showed that a complementary role of MEK activation, ERK hyperexpression, and PAC1 downregulation could contribute to determining the constitutive activation of ERK in acute leukemia. Our results suggest that ERK is constitutively activated in a majority of acute leukemias, and in addition to the activation of MEK, the hyperexpression of ERK and downregulation of PAC1 also contribute to constitutive ERK activation in acute leukemias.

Wernicke encephalopathy and beriberi during total parenteral nutrition attributable to multivitamin infusion shortage.

OBJECTIVE: Wernicke encephalopathy (WE) is an acute neurologic disorder characterized by a triad of ophthalmoplegia, ataxia, and mental confusion. WE is attributable to thiamine (vitamin B1) deficiency. Beriberi is the systemic counterpart of thiamine deficiency and often manifests in cardiovascular collapse. WE is usually associated with alcoholism and malnutrition. It has also been seen in people with gastrointestinal diseases with malabsorption. Patients who have received total parenteral nutrition (TPN) without proper replacement of thiamine have also developed WE. Since November 1996, there has been a shortage of multivitamin infusion (MVI). Many patients who were on chronic TPN with MVI ceased to receive the MVI and were converted to an oral form of the multivitamin. As a result, there have been several reports of children and adults on TPN who have developed WE as a result of thiamine deficiency. With this case report, we bring to attention the association of the MVI shortage and WE. Early diagnosis of WE is important, because if it is treated with thiamine in the acute stages, the neurologic and cardiovascular abnormalities can be reversed. CASE REPORT: We report a 20-year-old female patient with Crohn's disease who developed WE as a result of thiamine deficiency. She had Crohn's disease since age 9 years and was on chronic TPN. Two months before admission, MVI was discontinued in the TPN because of the shortage of its supply. An oral multivitamin tablet was substituted instead. She was admitted to the hospital for persistent vomiting. In the hospital, she continued to receive TPN without MVI, but continued taking an oral multivitamin preparation. Two weeks after admission, she developed signs of WE including diplopia, ophthalmoplegia, nystagmus, and memory disturbance. She also developed hypotension that was thought to be caused by beriberi. She was treated with 50 mg of intravenous thiamine. Within hours of the intravenous thiamine, her hypotension resolved. The day after the infusion, she no longer complained of diplopia, and her ophthalmoplegia had improved dramatically. Magnetic resonance imaging showed several areas of abnormally high signal on T2-weighted images in the brainstem, thalamus, and mamillary bodies. The topographic distribution of these changes was typical of WE. After 2 months, her mental status and neurologic status had recovered completely. CONCLUSION: WE and thiamine deficiency should be considered in all patients with malabsorption, malnutrition, and malignancies. WE from thiamine deficiency can occur as a result of cessation of MVI in the TPN infusion. Even if an oral multivitamin preparation is given instead of MVI, patients with malabsorption may not absorb thiamine adequately. Prompt diagnosis of WE is important because it is potentially fatal and readily treatable with thiamine supplementation. Early recognition of WE may be more difficult in children, because the classic triad of symptoms may not develop fully. Magnetic resonance imaging may be useful in these cases to confirm the diagnosis of WE. Because the shortage of MVI is expected to be a long-term, there are likely to be more cases of WE in the pediatric population of TPN-dependent children. Because there is no shortage of intravenous thiamine, it should be administered with TPN even if MVI is not available.

Pilot randomized controlled trial of Chinese herbal treatment for HIV-associated symptoms.

We wished to determine the short-term safety and efficacy of a Chinese medicinal herb preparation in treating symptoms of human immunodeficiency virus (HIV) infection in a 12-week randomized, double-blind, placebo-controlled clinical trial in a University-affiliated acquired immunodeficiency syndrome (AIDS) clinic at a public general hospital. Thirty adults with symptomatic HIV infection, no previous AIDS-defining diagnosis, and CD4+ counts of 0.200-0.499 x 10(9)/L (200-499/mm3) received 28 tablets each day of either a standardized oral preparation of 31 Chinese herbs or a cellulose placebo. Primary outcome measures were changes in life satisfaction, perceived health, and number and severity of symptoms. Other outcomes included adherence, and changes in weight, CD4+ count, depression, anxiety, physical and social function, and mental health. Two placebo- and no herb-treated subjects had mild adverse events (AE). Subjects on both arms reported taking 94% of prescribed tablets. No differences between treatment groups reached the p < 0.05 level. Life satisfaction improved in herb-treated [+0.86, 95% confidence interval (CI): +0.29, +1.43] but not in placebo-treated subjects (+0.20, 95% CI -0.35, + 0.75). Number of symptoms was reduced in subjects receiving herbs (-2.2, 95% CI -4.1, -0.3) but not in those receiving placebo (-0.3, 95% CI -3.2, +2.7). There were trends toward greater improvements among herb-treated subjects on all symptom subscales except dermatologic. Believing that one was receiving herbs was strongly associated with reporting that the treatment had helped (p < 0.005), but not with changes in life satisfaction or symptoms. There were improvements in life satisfaction and symptoms among subjects receiving the herbal therapy. Whether Chinese herbs are effective in the management of symptomatic HIV infection can be adequately addressed only by larger trials of longer duration.

Influence of molecular characteristics on clinical outcome in human immunodeficiency virus-associated non-Hodgkin's lymphoma: identification of a subgroup with favorable clinical outcome.

The relationship between clinical and molecular characteristics of 45 treated individuals with histologically-documented human immunodeficiency virus (HIV)-associated B-cell non-Hodgkin's lymphoma was examined to determine whether differences in molecular features of lymphoma were associated with differences in clinical outcome. Tissue specimens from these tumors were evaluated for evidence of Ig heavy-chain gene rearrangements using both Southern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR). Lymphomas were also evaluated for the presence of Epstein-Barr virus (EBV) DNA sequences and c-myc gene rearrangements. Twenty-five lymphomas were characterized as polyclonal and 20 as monoclonal. PCR amplification of expressed Ig variable (V)-region genes confirmed polyclonality in three extensively studied polyclonal lymphomas. The median CD4 count was significantly higher in the group with polyclonal disease (277/microL) than in the group with monoclonal disease (123/microL), P = .04. The complete response rate to therapy was significantly higher in patients with polyclonal disease (78%) and CD4 greater than 200/microL (81%) than in those with monoclonal disease (31%) and CD4 less than 200/microL (33%). CD4 count, clonality, and presence of EBV DNA sequences were the most important predictors of survival. Both Kaplan-Meier and Cox proportional hazards analyses showed a markedly prolonged survival in those patients with both CD4 > or = 200/microL and polyclonal disease. Histologically the polyclonal lymphomas were high grade in appearance and contained prominent macrophages. All seven surviving patients were in this group. Median survival for those individuals whose tumors contained EBV sequences was only 3.2 months (range, 0.4 to 19.5), whereas those with EBV- tumors survived for a median of 9.0 months (range, 0.7 to 65.2), P = .0007. These data indicate that molecular features of HIV-associated lymphomas may be important predictors of clinical outcome. These characteristics define a distinct subset of patients with polyclonal EBV- tumors and CD4 counts greater than 200/microL that appear to have a less aggressive clinical course.

Ideal digestible lysine level for early- and late-finishing swine.

Two hundred sixteen crossbred (PIC line 26 x Camborough 15) pigs were used in three trials to determine optimal digestible lysine levels during early (EF = 50 to 95 kg) and late (LF = 90 to 110 kg) finishing periods. Pigs were self-fed in sex groups of two in all trials. The assay diets for EF and LF periods were 11 and 10% CP corn-soybean meal diets, respectively, supplemented with threonine, methionine, tryptophan, valine, and isoleucine. Corn-soybean meal positive-control diets were included in each trial (14.5% CP for EF and 13.5% CP for LF). This dietary CP regimen was shown to give the same performance and carcass quality as a 17% CP corn-soybean meal diet fed during both EF and LF. Plateau portions of the lysine response curves resulted in performance levels that were equal to or greater than those achieved with pigs fed the 14.5/13.5% CP positive-control diets. Early-finishing pigs responded (P < .05) to graded doses of digestible lysine (.41 to .71%) for daily weight gain, gain:feed, longissimus muscle area, 10th-rib fat depth, lean gain, and plasma urea N. Digestible lysine requirement estimates based on average plateau points were .58% for EF barrows and .64% for EF gilts. Late-finishing pigs responded (P < .05) to digestible lysine doses (.35 to .65%) for daily weight gain, gain:feed, lean gain, and plasma urea N. Digestible lysine requirement estimates based on average plateau points were .49% for LF barrows and .52% for LF gilts.

Growth and plasma zinc responses of young pigs fed pharmacologic levels of zinc.

Three trials were conducted to evaluate high levels of Zn addition from various Zn sources on growth performance and plasma Zn responses of 8-kg pigs. Zinc supplements were added to 20% CP starting diets (125 mg of Zn/kg) containing antibiotics. Trial 1 was done to evaluate plasma Zn responses of pigs fed three different feed-grade Zn sources: ZnO where supplemental Zn levels were 0, 250, 500, 1,000, 3,000, and 5,000 mg/kg; ZnSO4 at 1,500 or 2,500 mg of Zn/kg; and a zinc-lysine complex (Zn-Lys) at 1,500 or 2,500 mg of Zn/kg. Plasma Zn concentration as a function of supplemental Zn intake was fitted to a broken-line for ZnO data and to simple linear models for ZnSO4 and Zn-Lys data. For ZnO, plasma Zn did not increase until concentrations > 1,000 mg Zn/kg were fed. Above this level, plasma Zn increased linearly (P < .01) for all three sources of Zn, although slopes of the ZnO and Zn-Lys response curves were 56% (P < .05) and 110%, respectively, of the ZnSO4 slopes. In Trial 2, five diets were fed: basal, 3,000 and 5,000 mg of Zn/kg from ZnO, and 3,000 and 5,000 mg of Zn/kg from ZnSO4. Daily gain and daily feed intake were increased (P < .05) by ZnO addition, regardless of level, whereas ZnSO4 addition increased these performance indices only at the 3,000 mg of Zn/kg level of supplementation. Plasma Zn responses to ZnSO4 addition were almost double those of ZnO addition.(ABSTRACT TRUNCATED AT 250 WORDS)

[Plinius and Greek physicians in Rome: the concept of nature and medical critique in Naturalis Historia]. / Plinius und die griechischen Arzte in Rom: Naturkonzeption und Medizinkritik in der Naturalis Historia.

Pliny's historical outline of the development of medicine, in Natural History 29.1-27, is our primary source concerning the reception of scientific medicine at Rome during the later Republic and early Empire. Here, as elsewhere, Pliny handles Greek doctors and their medical practices with vehement disapproval. But this attitude, at first glance anti-Hellene, traditionalistic, and critical of his coevals, arises from more deeply rooted notions: a specific conception of nature which can be shown to be the basis of Pliny's critique of medicine and his own times. Reconstruction of this "Plinean" conception reveals a view of nature marked by Stoic terminology and categories, though in fact derivate from various sources, idiosyncratic and characterized by a genuine love of and respect for nature and her creations. True comprehension of the lessons offered by nature, resulting in concrete mores of behaviour and moral categories, as opposed to theory and speculation, is the proper modus operandi for Pliny. And thus, with regard to the human process of self-discovery in the natural world, medicine plays a decisive role--for providential nature displays herself most clearly in the production of healing substances. Pliny notes among the proponents of scientific medicine, a general disregard for nature and her rules, while he finds just the opposite in traditional medicine. His own accomplishment resides not only in the safeguarding of numberless recipies from the world of folk medicine, but also in the facts that he under-pins these traditional methods of healing, and their basic principles, with a specific conception of nature, and that he marks out an exceptionally important place for traditional methods of healing in the canon of general knowledge.

Nutritive value of oat flour and oat bran.

Oat flour, the by-product resulting from commercial production of oat bran, was analyzed to contain 7.7% moisture, 11% CP, 6% crude fat, 8.8% NDF, 1.56% ash (.10% Ca, .23% P), 4,265 kcal/kg GE, .41% lysine, .36% threonine, .17% tryptophan, .21% methionine and .34% cystine. Chick bioassays revealed that lysine and threonine were the first- and second-limiting amino acids in oat flour. Slope-ratio protein quality assessment indicated that the protein quality of oat flour was similar to that of dehulled soybean meal. True ME (corrected for N retention, i.e., TMEn) of oat flour for adult cockerels was 3,726 kcal/kg. A P bioavailability assay with chicks indicated that the P in oat flour was 59.7% bioavailable relative to a KH2PO4 standard. Oat bran was analyzed to contain 9.7% moisture, 15% CP, 6.2% crude fat, 19.2% NDF, 2.33% ash (.12% Ca, .41% P), 4,316 kcal/kg GE, .59% lysine, .47% threonine, .18% tryptophan, .24% methionine and .44% cystine. Protein quality assessment in chicks indicated that the protein quality of oat bran was similar to that of dehulled soybean meal. True MEn of oat bran was found to be 3,449 kcal/kg. Of the .41% total phosphorus in oat bran, 42.2% was bioavailable, relative to the KH2PO4 standard.

Potentiation of the combination of pancuronium and metocurine by halothane and isoflurane in humans with and without renal failure.

Dose-response relationships for a 1:4 weight ratio-mixture of pancuronium and metocurine were studied during inhalational anesthesia with halothane and isoflurane in patients with and without renal failure. The time for recovery from 10 to 20% of control thumb twitch tension also was determined. In subjects with normal renal function, relaxant doses required for 95% twitch height suppression (ED95) were 50% of those predicted by simple addition of effects when used with a balanced anesthetic technique, 37% of predicted when used with 1.3 MAC halothane, and 25% of predicted when used with 1.3 MAC isoflurane (P less than 0.05). In subjects with renal failure, ED95 values for the combination were 40% of predicted when used with 1.2 MAC halothane and 45% of predicted when used with 1.2 MAC isoflurane (NS). For relaxants used singly in renal failure, pancuronium alone was slightly enhanced by 1.2 MAC halothane (85% of predicted), while 1.1 MAC isoflurane reduced the ED95 to 57% of predicted (P less than 0.05). Similar results were obtained for metocurine alone when used in renal failure (77 and 58% of predicted when used with halothane and isoflurane, respectively) (NS). Predicted values are published results for balanced anesthesia in normals. Recovery times were prolonged twofold in renal failure (P less than 0.05). Thus, the combination of pancuronium and metocurine is synergistic to the same degree in normals and in renal failure patients, but the total blockade produced by the combination is enhanced by halothane and isoflurane only in normals.