Relationship between antigen release and antibody response of infectious coryza water-in-oil-in-water emulsion vaccines

The relationship between the antigen release from formulations in vitro and the antibody response after administration of water-in-oil-in-water (W/O/W) emulsion vaccines containing Haemophilus paragallinarum (Hpg) was studied in chickens. Increases of sorbitan sesquioleate volume in the formulation led to slower antigen release and tended to induce higher hemagglutination-inhibition (HI) antibody titers. In addition, the vaccines prepared with internal aqueous phase:oil phase:external aqueous phase (A:O:A) ratios of 3:4:3 and 3:3:4 also showed slower release of antigen and higher HI antibody titer compared with those of an A:O:A ratio of 3:2:5. Vaccines prepared with polyoxyethylene (POE)(10) hydrogenated castor oil or POE(40) hydrogenated castor oil instead of sorbitan sesquioleate showed higher release and lower antibody HI titers. As a result, HI antibody titers at 6 wk after vaccination were inversely related to antigen release, as determined by the release test. The correlation coefficient was 0.942. In infectious coryza W/O/W emulsion vaccines, the slow release of antigen from the formulation induced and maintained high HI antibody titers of Hpg.

Aldosterone overproduction and CYP11B2 mRNA overexpression in vessels of spontaneously hypertensive rats

Aldosterone is synthesized in extra-adrenal tissues such as blood vessels and brain. Damage to blood vessels could play a crucial role in perpetuating hypertension. In this study, we determined both aldosterone production and aldosterone synthase gene-CYP11B2 mRNA expression in vessels of spontaneously hypertensive rats (SHR). The results showed that aldosterone was overproduced in the vasculature of SHR, by means of ex vivo mesenteric artery perfusion, HPLC, and RIA, and that CYP11B2 mRNA expression was upregulated in aortas of SHR, confirmed by RT-PCR and Southern blot.

Adjuvanticity and inflammatory response following administration of water-in-oil emulsions prepared with saturated hydrocarbons in chickens

Water-in-oil emulsions containing bovine serum albumin (BSA) as a model antigen were prepared using aliphatic saturated hydrocarbons with carbon number from 12 to 18, and were tested in chickens. Straight-chain hydrocarbons induced higher antibody titers against BSA after administration than branched-chain hydrocarbons. n-C16H34 and n-C18H38 maintained high antibody titers even at 32 weeks after administration, compared with n-C12H26, n-C14H30 and n-C15H32. n-C12H26 and n-C14H30 raised concentrations of sialic acid and creatine kinase in plasma, both of which are important markers of inflammatory responses, immediately after administration. n-C16H34 and n-C18H38 did not raise the values of these markers. These results indicated that n-C16H34 and n-C18H38 induced elevated and sustained immune responses without severe adverse reactions in chickens.

Relation between antigen release and immune response of oil adjuvanted vaccines in chickens

The relationship between release properties of the model antigen, bovine serum albumin (BSA), from formulations in vitro and immune response after administration of various oil adjuvanted vaccines containing liquid paraffin was examined in chickens. The vaccine prepared at an hydrophile-lipophile-balance (HLB) number of 4.8 showed slower release of BSA and higher immune response on injected chickens than that with an HLB number of 6.0. Decreases of aqueous volume ratio in the formulation also led to slower release of BSA and higher immune response. The slower release rate of BSA showed higher ELISA antibody titer even at 20 weeks after vaccination. The ELISA antibody titer inversely was related to the constant release rate, k, calculated from the in vitro release test. The correlation coefficient was 0.863. The immune response of oil adjuvanted vaccines containing Haemophilus paragallinarum agreed well with these results with BSA. Our results indicated that a stronger and more prolonged immune response of oil adjuvanted vaccines was achieved by slower release rate of antigen from the formulation. In addition, there was a good correlation between immune response and the value of k.

Neuropharmacology of control of respiratory rhythm and pattern in mature mammals

This review summarizes the current understanding of the neurotransmitters and neuromodulators that are involved, firstly, in respiratory rhythm and pattern generation, where glutamate plays an essential role in the excitatory mechanisms and glycine and gamma-aminobutyric acid mediate inhibitory postsynaptic effects, and secondly, in the transmission of input signals from the central and peripheral chemoreceptors and of motor outputs to respiratory motor neurons. Finally, neuronal mechanisms underlying respiratory modulations caused by respiratory depressants and excitants, such as general anesthetics, benzodiazepines, opioids, and cholinergic agents, are described.

11beta-hydroxysteroid dehydrogenase in human vascular cells

Aldosterone selectivity in mineralocorticoid target tissues is mainly due to 11beta-hydroxysteroid dehydrogenase (11betaHSD), which converts cortisol to its inactive metabolite cortisone in humans. The defect of dehydrogenase activity would thus allow type 1 mineralocorticoid receptor (MR) to be occupied mostly by cortisol. It has been postulated that 11betaHSD type 2 (11betaHSD2) plays a significant role in conferring ligand specificity on the MR. We have demonstrated the diminished dehydrogenase activity in resistance vessels of genetically hypertensive rats. However, the mechanism that could link impaired vascular 11betaHSD activity and elevated blood pressure has been unclear. In this study, we showed the enzyme activity in human coronary artery smooth muscle cells. Glucocorticoids and mineralocorticoids increase vascular tone by up-regulating the receptors of pressor hormones such as angiotensin II (Ang II). Next, we found that physiological concentrations of a cortisol-induced increase in Ang II binding were significantly enhanced by the inhibition of dehydrogenase activity with an antisense DNA complementary to 11betaHSD2 mRNA, and the enhancement was partially but significantly abolished by a selective aldosterone receptor antagonist. This may indicate that impaired dehydrogenase activity in vascular wall results in increased vascular tone by the contribution of cortisol, which acts as a mineralocorticoid. In congenital 11betaHSD deficiency and after the administration of 11betaHSD inhibitors, suppression of dehydrogenase activity in the kidney has been believed to cause renal mineralocorticoid excess, resulting in sodium retention and hypertension. These results show that vascular 11betaHSD activity could influence blood pressure without invoking renal sodium retention.

Contribution of NMDA receptors to activity of augmenting expiratory neurons in vagotomized cats

To identify the NMDA receptor-mediated mechanism in augmenting expiratory (E2) neurons, the effects of systemic and local application of dizocilpine on spontaneous and evoked postsynaptic potentials (PSPs) were investigated in decerebrate and vagotomized cats. Intravenously applied dizocilpine reduced the inhibitory PSPs during inspiration and stage 1 expiration, but had little effect on the excitatory PSPs during stage 2 expiration. Iontophoresed dizocilpine caused a continuous hyperpolarization throughout the respiratory cycle. Dizocilpine had no effect on vagally evoked PSPs. These results suggest that the NMDA mechanisms are involved presynaptically in periodic postsynaptic inhibitions and postsynaptically in tonic excitation in E2 neurons.

Synaptic interactions between respiratory neurons during inspiratory on-switching evoked by vagal stimulation in decerebrate cats

To elucidate neuronal mechanisms underlying phase-switching from expiration to inspiration, or inspiratory on-switching (IonS), postsynaptic potentials (PSPs) of bulbar respiratory neurons together with phrenic nerve discharges were recorded during IonS evoked by vagal stimulation in decerebrate and vagotomized cats. A single shock stimulation of the vagus nerve applied at late-expiration developed an inspiratory discharge in the phrenic neurogram after a latency of 79+/-11 ms (n = 11). Preceding this evoked inspiratory discharge, a triphasic response was induced, consisting of an early silence (phase 1 silence), a transient burst discharge (phase 2 discharge) and a late pause (phase 3 pause). During phase 1 silence, IPSPs occurred in augmenting inspiratory (aug-I) and expiratory (E2) neurons, and EPSPs in postinspiratory (PI) neurons. During phase 2 discharge, EPSPs arose in aug-I neurons and IPSPs in PI and E2 neurons. These initial biphasic PSPs were comparable with those during inspiratory off-switching evoked by the same stimulation applied at late-inspiration. In both on- and off-switching, phase-transition in respiratory neuronal activities started to arise concomitantly with the phrenic phase 3 pause. These results suggest that vagal inputs initially produce a non-specific, biphasic response in bulbar respiratory neurons, which consecutively activates a more specific process connected to IonS.

alphaPIX nucleotide exchange factor is activated by interaction with phosphatidylinositol 3-kinase

p21-activated kinase (PAK) is a common effector protein of the small GTPases Cdc42 and Rac, leading to the activation of downstream mitogen activated protein kinases. PAK also mediates polarized cytoskeletal changes induced by these GTPases. The recently identified PAK-interacting exchange factor (PIX) acts as a guanine nucleotide exchange factor on Rac, and colocalizes with PAK in a focal complex, but little is known about the associated signaling cascades, including upstream activators of PIX. In this study, we show that one of the isoforms of PIX, alphaPIX, is activated by signaling cascades from the platelet-derived growth factor (PDGF) receptor and EphB2 receptor, and from integrin-induced signaling through phosphatidylinositol 3-kinase (PI3-kinase). alphaPIX is activated by forming a complex with these receptors either via association with PAK and Nck, or direct association with the p85 regulatory subunit of PI3-kinase. Synthetic phosphoinositide and membrane targeted PI3-kinase augmented the alphaPIX activity in vivo. In Xenopus, aggregates of mesodermal cells derived from embryos microinjected with alphaPIX significantly increased the peripheral spreading on fibronectin substrate in response to PDGF through PI3-kinase. These results indicate that alphaPIX is activated by PI3-kinase, and is involved in the receptor mediated signaling leading to the activation of the kinase activity of PAK, and the migration of mesodermal cells on extracellular matrix.

GABA(A) receptor-mediated inspiratory termination evoked by vagal stimulation in decerebrate cats

To identify the GABAergic inhibitory mechanisms involved in inspiratory termination or off-switching (IOS), the effects of a specific enhancer of GABA(A) receptors, midazolam, and an antagonist, bicuculline, on vagally evoked inspiratory inhibitions and IOS were investigated in decerebrate cats. Stimulation of vagal afferents at late inspiration provoked either reversible inspiratory inhibition or IOS, depending on the stimulus intensity. Each response occurred at a constant latency (phase 1). The reversible response was triphasic, consisting of an early (phase 2) inhibition, a brief (phase 3) excitation and a late (phase 4) inhibition in the phrenic neurogram, and early (phase 2) IPSPs, brief (phase 3) EPSPs and late (phase 4) IPSPs in bulbar inspiratory (I) neurones. With an increasing stimulus intensity, phase 4 inhibitions were increased in amplitude and duration, leading to IOS. Midazolam (0.1 mg/kg i.v.) increased more selectively phase 4 IPSPs than phase 2 IPSPs in I neurones, and decreased the threshold for evoking IOS by producing an earlier and larger phase 4 IPSPs. Bicuculline (1.0 mg/kg i.v.) had an opposite effect. These results suggest that the late inhibitory response evoked by vagal stimulation in the I neuronal pool organizes an initial phase of IOS which is mediated by GABA(A) receptors.

Related changes in sympathetic activity, cerebral blood flow and intracranial pressure, and effect of an alpha-blocker in experimental subarachnoid haemorrhage

We investigated the changes in sympathetic nerve activity (SNA) and cerebral blood flow (CBF) with or without increase in intracranial pressure (ICP) in the acute stage of experimental subarachnoid haemorrhage (SAH). ICP was increased or controlled by rapid or slow injection of blood and saline, and the effect of an alpha-blocker, phentolamine, was also investigated in each condition. Following marked increase in ICP induced by rapid injection of blood or saline, increase in intracranial and general SNA and decrease in CBF were observed. Both changes were significantly decreased in magnitude by prior administration of phentolamine. When increase in ICP was not induced, by slow injection of blood, both SNA and CBF decreased, and these changes were alleviated by phentolamine. However, when increase in ICP was not induced by saline, neither SNA nor CBF significantly changed. These findings suggest that marked increase in ICP is the primary cause of the pathological changes occurring immediately after SAH, and that the decrease in CBF in mild SAH without increase in ICP is caused by blood itself. Administration of an alpha-blocker may be effective in improving the abnormal sympathetic nervous system induced by marked increase in ICP.

NMDA receptor-mediated inspiratory off-switching in pneumotaxic-disconnected cats

The pneumotaxic center is thought to govern inspiratory off-switching (IOS), and blockade of N-methyl-D-aspartate (NMDA) receptors by dizocilpine impairs IOS causing apneusis. The present study is to examine whether the NMDA receptor-mediated IOS mechanism functions in the medullary respiratory network after disconnecting the pneumotaxic center. In decerebrate and vagotomized cats, the nucleus parabrachialis medialis (NPBM) and vagus nerves were stimulated to evoke IOS and a dorsal pontine transection was performed while the central respiratory activity was recorded in phrenic neurogram. The transection eliminated the NPBM-stimulated IOS but not the vagally evoked IOS, and developed two types of respiration; eupnea in 12 and apneusis in six out of 18 cats. Apneustic respiration was not changed into eupneic one by changing the end-tidal CO2 level. In animals displaying eupnea after the transection, dizocilpine (0.3 mg/kg i.v.) produced apneusis, characterized by a prolonged inspiration, a shortened stage 1 expiration and an unchanged stage 2 expiration. Dizocilpine caused no further change in the apneustic pattern induced by the transection. The present results suggest that the medullary respiratory network is able to generate a eupneic respiration after disconnecting the pontine pneumotaxic center, and the NMDA mechanism plays an important role in the medullary respiratory network.

Lisinopril decreases plasma free testosterone in male hypertensive patients and increases sex hormone binding globulin in female hypertensive patients

The effect of an angiotensin-converting enzyme inhibitor, lisinopril, on gonadal hormones was assessed in 20 patients with essential hypertension. A daily dose of 5 to 20 mg of lisinopril was administered for 6 mo. In male patients, the free testosterone (f-T) concentration decreased significantly (before, 13.8+/-2.4 pg/ml; after, 9.9+/-1.5 pg/ml: mean +/- SEM, p < 0.05), whereas the plasma total testosterone (T), estradiol (E2), and sex hormone binding globulin (SHBG) concentrations were not significantly affected. Lisinopril had no effect on plasma T, f-T, or E2 concentrations in female patients, but significantly increased the plasma SHBG concentration (before, 48.0 6.1 nmol/l; after, 62.7+/-6.7 nmol/l: p < 0.01). The results of this preliminary study suggest that lisinopril affects plasma f-T and SHBG concentrations. The clinical implications of lisinopril-induced changes in plasma f-T and SHBG concentrations remain to be clarified.

Thrombolytic therapy for cerebral embolism

SUMMARY

We summarized our clinical experience of thrombolytic therapy for cerebral embolism to evaluate the relation between the prognosis and the occlusion site, and the role of pre-treatment CBF measurement for supratentorial cerebral embolism. 56 cases of thrombolysis were analyzed and results were compaired with conservative medical therapy group. For ICA embolism, we stopped thrombolysis in the early period because of its poor collateral circulation. MCA embolism seemed to be a good candidate for this treatment and results were significantly better than the conservative medical therapy group in good recovery rate, severe disablity rate and large size infarction rate. In basilar artery embolism, thrombolysis seemed to be the most effective treatment in spite of the high mortality rate. Pre-treatment CBF measurement was important and useful to estimate the severity of ischemia, and it could make it possible to avoid severe hemorrhagic complications.

99mTc-tetrofosmin uptake in bone metastases from breast cancer

99mTc-tetrofosmin myocardial imaging was performed in a 62-year-old woman who had undergone standard radical mastectomy for right breast cancer 6 years ago. Although the result was negative for the ischemic heart disease, it showed abnormal accumulation corresponding to the bone metastases in the spine. We believe that 99mTc-tetrofosmin imaging is helpful in detecting bone metastases from breast cancer.

Synaptic potentials in respiratory neurones during evoked phase switching after NMDA receptor blockade in the cat

1. Blockade of NMDA receptors by dizocilpine impairs the inspiratory off-switch (IOS) of central origin but not the IOS evoked by stimulation of sensory afferents. To investigate whether this difference was due to the effects of different patterns of synaptic interactions on respiratory neurones, we stimulated electrically the superior laryngeal nerve (SLN) or vagus nerve in decerebrate cats before and after i.v. administration of dizocilpine, whilst recording intracellularly. 2. Phrenic nerve responses to ipsilateral SLN or vagal stimulation were: at mid-inspiration, a transient inhibition often followed by a brief burst of activity; at late inspiration, an IOS; and at mid-expiration, a late burst of activity. 3. In all neurones (n = 16), SLN stimulation at mid-inspiration evoked an early EPSP during phase 1 (latency to the arrest of phrenic nerve activity), followed by an IPSP in inspiratory (I) neurones (n = 8) and by a wave of EPSPs in post-inspiratory (PI) neurones (n = 8) during phase 2 (inhibition of phrenic activity). An EPSP in I neurones and an IPSP in PI neurones occurred during phase 3 (brief phrenic burst) following phase 2. 4. Evoked IOS was associated with a fast (phase 1) activation of PI neurones, whereas during spontaneous IOS, a progressive (30-50 ms) depolarization of PI neurones preceded the arrest of phrenic activity. 5. Phase 3 PSPs were similar to those occurring during the burst of activity seen at the start of spontaneous inspiration. 6. Dizocilpine did not suppress the evoked phrenic inhibition and the late burst of activity. The shapes and timing of the evoked PSPs and the changes in membrane potential in I and PI neurones during the phase transition were not altered. 7. We hypothesize that afferent sensory pathways not requiring NMDA receptors (1) terminate inspiration through a premature activation of PI neurones, and (2) evoke a late burst of phrenic activity which might be the first stage of the inspiratory on-switch.

Micacocidin A, B and C, novel antimycoplasma agents from Pseudomonas sp. II. Structure elucidation

Metal-containing novel heterocyclic antibiotics, micacocidin A (1), B (2), and C (3) have been isolated from the culture filtrate of Pseudomonas sp. No. 57-250. The structure and absolute configuration of micacocidin A, an octahedral Zn2+ complex, was determined by X-ray crystallographic analysis. And then, the structures of the two congeners, micacocidin B (Cu2+ complex) and C (Fe3+ complex) were investigated by employing one dimensional and two dimensional homonuclear and heteronuclear NMR spectroscopies and mass spectrometry.

[Reliability and factorial structure of a rating scale for persistent vegetative state]

We developed a new rating scale, Kohnan Vegetative Score, to measure severity and small clinical changes in vegetative state patients. It has 7 items corresponding to the conditions of vegetative state by Japanese Society of Neurosurgery: motor function, food ingestion, urination and defecation, eye movement, vocalization, communication, and facial expression. Each item is rated in 5 ordinal categories: slight (score = 1), mild(2), moderate(4), and extreme(5). The sum of the scores is used as the summary score, which ranges from 7 to 35, and high score means 'severe'. We examined the reliability and the factorial structure of the Kohnan Vegetative Score. The subjects were 10 patients who met the conditions of vegetative state. Four neurosurgeons rated the subjects, and then 2 of them repeated the rating after one week interval. As a measure of reliability, the (weighted) Kappa coefficient proposed Cohen (1960, 1968) was calculated for each item, and the intraclass correlation coefficient (ICC) was calculated for the summary score. To analyze the factorial structure, the factor analysis was carried out. The minimum and the maximum weighted Kappa values were 0.44 and 0.64 for intra-rater reliability, and 0.37 and 0.69 for inter-rater reliability, respectively. Concerning the factorial structure, the contribution of the first factor was 91.5% which indicated the unidimensionality of the scale. The ICC's estimate for the summary score were 0.90 (95% C.I.: 0.766-0.970). On the basis of these results, the Kohnan Vegetative Score has unidimensionality and high reliability enough for a practical use.

Immunohistochemical and structural characteristics of the reticular framework of the white pulp and marginal zone in the human spleen

BACKGROUND

The reticular framework of the white pulp (WP) and marginal zone (MZ) consists of reticulum cells and reticulin fibers. The antigenic heterogeneity of the reticular framework is well documented in the mouse and rat spleen. The aim of the present study is to characterize the reticular framework of the WP and MZ of the human spleen.

METHODS

Nine surgically resected human spleens were investigated. Five of the nine spleens were perfused. Formalin-fixed materials were embedded in paraffin and serial sections prepared for hematoxylin-eosin, silver staining, and immunohistochemical examination. Electron and immuno-electron microscopy were also applied. Using confocal laser scanning microscopy, the reticular framework was analyzed three-dimensionally.

RESULTS

The reticulin fibers of the framework were immunostained for type IV collagen in the WP and MZ. The WP was three-dimensionally delimited by the alpha-smooth muscle actin (alpha-SMA)-positive reticulum cells. In the WP, the distribution of alpha-SMA-positive reticulum cells formed the reticular framework of the periarteriolar lymphoid sheath (PALS). They also ensheathed the reticulin fibers. Interdigitating cells (IDCs) were scattered throughout the framework. A few IDCs attached to the framework. In the lymph follicle (LF), reticulum cells were not alpha-SMA-positive. The mesh of follicular dendritic cells (FDCs) was found in the germinal center. In places, the reticulin fibers were involved in the mesh of the FDCs and covered by the cytoplasm of FDCs. In the MZ, alpha-SMA-positive reticulum cells were arranged in a mesh pattern and ensheathed the fine reticulin fibers.

CONCLUSION

The reticular framework of the PALS, LF, and MZ is specialized into heterogeneous components in the human spleen. The heterogeneity of the framework may induce the segregation of T and B lymphocytes.

Brain nitric oxide synthase messenger RNA in central mineralocorticoid hypertension

The mechanism underlying the central hypertensinogenic effects of mineralocorticoids remains unclear. Given that nitric oxide (NO) is thought to act at autonomic sites in the brain to regulate arterial blood pressure, the effects of the potent mineralocorticoids aldosterone and 19-noraldosterone on the abundance of neuronal NO synthase (nNOS) mRNA in the brain were investigated. Wistar-Kyoto rats received a continuous intracerebroventricular infusion of aldosterone or 19-noraldosterone (5 ng/h) from an implanted osmotic minipump for 4 weeks. Total RNA was purified from microdissected tissue blocks containing the hypothalamus, dorsal medulla, rostral ventrolateral medulla, or caudal ventrolateral medulla, and changes in the abundance of nNOS mRNA were determined with a semiquantitative competitive polymerase chain reaction method. Blood pressure was significantly increased in rats 2, 3, and 4 weeks after the onset of intracerebroventricular aldosterone or 19-noraldosterone infusion compared with that in animals receiving vehicle. Subcutaneous infusion of either mineralocorticoid had no effect on blood pressure. Compared with controls, rats treated with aldosterone or 19-noraldosterone for 4 weeks showed significant decreases in the amount of nNOS mRNA in the hypothalamus and rostral and caudal ventrolateral medulla. These data suggest that reduced nNOS activity may contribute to the increase in blood pressure in rats with central mineralocorticoid-induced hypertension.

A modified coaxial compound micropipette for extracellular iontophoresis and intracellular recording: fabrication, performance and theory

Investigation of the identity and modes of action of neurotransmitters in the mammalian central nervous system can be facilitated by simultaneous intracellular recording of membrane potential and extracellular iontophoresis of agonists and antagonists. We describe here techniques for conveniently constructing a compound microelectrode, originally described by Sonnhof (Pflugers Arch 341, 351-358, 1973), suitable for such studies. The Sonnhof electrode consists of two components, a centraxial micropipette for recording membrane potential surrounded by a cylindrical array of 6 pipettes for iontophoresis. The cylindrical array tapers coaxially and terminates in 6 contiguous, crescent-shaped orifices surrounding the terminal portion of the central pipette, 25 - 50 microm from the tip. Pipettes were constructed from borosilicate glass tubing of 1-mm wall thickness having a 10-mm or 16-mm outer diameter. The resistances, flux and transport numbers for iontophoresis of glycine were measured for pipettes constructed from both sizes of glass. Flux increased with increasing levels of current, and transport number decreased with increasing micropipette resistance. A spherical diffusion model points out the steep dependence of steady state concentration on diffusional distance, stressing the importance of diminishing the distance between the iontophoresis source and the recording site. This is particularly true when brief pulses of current are used.