Humans immunized with Streptococcus mutans antigens by mucosal routes

Strategies aimed at the prevention of Streptococcus mutans infection and dental caries include mucosal immunization, which results in salivary anti-S. mutans responses. The purpose of this study was to evaluate the effectiveness of nasal vs. tonsillar immunization with S. mutans antigens in inducing salivary immune responses. Twenty-one adult subjects were immunized twice, within a seven-day interval, with a glucosyltransferase-enriched preparation (E-GTF) administered by nasal or tonsillar topical spray. Parotid saliva, nasal wash, and serum were collected prior to and at one- to two-week intervals for 3 months following immunization and were assayed by ELISA for anti-E-GTF activity. Results were analyzed by means of the mixed-models procedure with p < 0.05 level of significance. Significantly higher anti-E-GTF responses were detected in saliva and nasal wash samples from the group immunized by the nasal compared with the tonsillar route, indicating that nasal immunization was more effective in inducing mucosal responses in adults.

Human salivary immunoglobulin and antigen-specific antibody activity after tonsillectomy

The importance of the lymphoid tissue collectively known as Waldeyer's ring, which includes the palatine, lingual and nasopharyngeal tonsils, in the induction and contribution of specific antibody responses in human saliva is not clear. The purpose of this study was to determine whether salivary immunoglobulin A (IgA) levels differ in quantity and quality between subjects who have had a tonsillectomy and age, sex and race-matched controls. Parotid saliva, whole saliva, and blood serum samples were collected from 25 volunteer children who had undergone tonsillectomy (T-) within 6-14 months of sampling and from 25 age, sex and race-matched controls. The levels of total IgA (and subclasses) in saliva, and of antigen-specific salivary IgA and serum IgA and IgG antibodies to 4-9 relevant antigens were analyzed by ELISA. No significant difference was observed in the mean total IgA and IgA subclass levels in parotid and whole saliva, although the mean levels for children with a T- were slightly lower. Children with a T- had significantly higher parotid salivary IgA and IgA1 specific/total activity than controls. The total and specific whole saliva IgA and the specific serum IgA or IgG activities were not significantly different from controls. These results indicate an association between the removal of tonsils and increased levels of specific IgA activity in parotid saliva within the first year after a T-.

Adjuvant activity of monophosphoryl lipid A for nasal and oral immunization with soluble or liposome-associated antigen

The effectiveness of monophosphoryl lipid A (MPL) as a mucosal adjuvant was investigated following oral or intranasal (i.n.) administration of an aqueous adjuvant formulation of MPL (MPL-AF) added to soluble antigen or liposomal antigen or incorporated into liposomal antigen membranes. Groups of BALB/c female mice were immunized with 50 to 100 microg of free or liposomal Streptococcus mutans crude glucosyltransferase (C-GTF) with or without MPL-AF added to the vaccine or incorporated into the liposomal membrane. Plasma, saliva, vaginal wash, and fecal extract samples were collected biweekly following immunization and assessed for antigen-specific antibody activity by enzyme-linked immunosorbent assay (ELISA). Mice immunized by the i.n. route had higher levels of salivary, plasma, and vaginal immunoglobulin A (IgA) anti-C-GTF responses and higher levels of plasma IgG anti-C-GTF than the orally immunized groups. A second administration of the vaccine 14 weeks after the initial immunization resulted in an anamnestic response to C-GTF resulting in 10- and 100-fold increases in saliva and plasma IgA and plasma IgG, respectively (in the i.n. immunized groups). Mice receiving a second i.n. immunization with liposomal antigen and MPL-AF had higher salivary IgA anti-C-GTF responses than mice immunized with antigen plus MPL-AF or liposomal antigen (P < 0.05). Plasma IgG anti-C-GTF activity was highest in mice immunized by the i.n. route with antigen formulations containing MPL-AF (P < 0.05). These results demonstrate the effectiveness of MPL-AF as an adjuvant for potentiating mucosal and systemic immune responses to liposomal C-GTF following i.n. immunization.

The actions of synaptically released zinc at hippocampal mossy fiber synapses

Zn2+ is present at high concentrations in the synaptic vesicles of hippocampal mossy fibers. We have used Zn2+ chelators and the mocha mutant mouse to address the physiological role of Zn2+ in this pathway. Zn2+ is not involved in the unique presynaptic plasticities observed at mossy fiber synapses but is coreleased with glutamate from these synapses, both spontaneously and with electrical stimulation, where it exerts a strong modulatory effect on the NMDA receptors. Zn2+ tonically occupies the high-affinity binding site of NMDA receptors at mossy fiber synapses, whereas the lower affinity voltage-dependent Zn2+ binding site is occupied during action potential driven-release. We conclude that Zn2+ is a modulatory neurotransmitter released from mossy fiber synapses and plays an important role in shaping the NMDA receptor response at these synapses.

A controlled clinical study of the effect of nasal immunization with a Streptococcus mutans antigen alone or incorporated into liposomes on induction of immune responses

Recent attention to mucosal immunization strategies has been focused on the nasal route for vaccine delivery. This study was designed to determine the effectiveness of a liposome-protein vaccine compared to that of a protein-only vaccine in inducing immune responses in humans. Healthy subjects were randomly assigned to two groups and immunized intranasally with a crude antigen preparation rich in glucosyltransferase (C-GTF) from Streptococcus mutans, alone or in liposomes. Parotid saliva, nasal wash, and serum were collected prior to and at weekly intervals following immunization and were analyzed for anti-C-GTF activity by enzyme-linked immunosorbent assay. The levels of immunoglobulin A (IgA) anti-C-GTF activity in the nasal wash from both groups after immunization increased to a mean peak of fivefold over the baseline level on day 28. Salivary IgA anti-C-GTF responses were induced to a lesser extent. IgG and IgA anti-C-GTF responses in serum were detected on day 14. The IgA responses were predominantly of the IgA1 subclass. These results show that C-GTF vaccines were more effective in inducing a local secretory IgA antibody response than a salivary or serum response when they were given intranasally. The IgA1 anti-C-GTF response in nasal wash samples for liposomal antigen versus antigen only was the only response which was significantly different (P < 0.04). This suggests that the form of the antigen affects the magnitude of the local mucosal response but not that of a disseminated response. These results provide evidence for the effective use of a nasal protein vaccine in humans for the induction of mucosal and systemic responses.

A brief history of printing of lithographic medical books in modern times

A large number of lithographic medical books came out within about 100 years after the introduction of lithography technique from the west. There are about 1000 extant lithographic medical books among which 500 still extant as lithographic edition in our country. The development of lithographic medical book could be divided into three stages: the embryonic stage, the prosperous stage and the devlined stage. In spite of the shortcomings that the printing was not exquisite and the textual proofreading was not precise, the value of these lithographic medical books could not be underrated in preserving the medical documents, spreading the medical knowledge and promoting the confluence of TCM and western medicine.

Nasal immunization of humans with dehydrated liposomes containing Streptococcus mutans antigen

Five healthy female adult volunteers were intranasally immunized twice (7-day interval) with 250 micrograms of a crude glucosyltransferase (GTF) preparation from Streptococcus mutans in liposomes. Parotid saliva, nasal wash, and serum were collected prior to and at weekly intervals for 6 weeks following the first immunization for analysis of anti-GTF activity by enzyme-linked immunosorbent assay. The levels of IgA1 anti-GTF activity increased in the nasal wash from all five individuals after immunization. Increases in salivary IgA1 and IgA2 anti-GTF activities were observed to a lesser extent. Increased serum IgM and IgA (but not IgG) anti-GTF activities were seen in immunized subjects. Nasal immunization with a dehydrated liposome-protein vaccine was effective in inducing an apparent secretory IgA antibody response, which was primarily of the IgA1 subclass. These results provide the first evidence of the effective use of a nasal liposome-protein vaccine in humans.

Structure and dynamics of pentaglycyl bridges in the cell walls of Staphylococcus aureus by 13C-15N REDOR NMR

Whole cells and cell-wall fractions of Staphylococcusaureus have been labeled by various combinations of [1-13C]glycine, [15N]glycine, L--6-13C-lysine, L--6-15N-lysine, D--1-13C-alanine, and D--15N-alanine. The resulting materials have been examined using 13C and 15N solid-state, magic-angle spinning NMR techniques including cross-polarization, double cross-polarization, and rotational-echo double resonance. The results of these measurements indicate that the peptidoglycan glycyl bridges are complete (five units long) and form cross-links between three-quarters of all peptide stems. The pentaglycyl bridges are immobilized in lyophilized cell-wall fractions in a compact conformation with inter-residue spacings comparable to those of an alpha helix. The bridges have a similar compact conformation in intact whole cells, regardless of whether the cells have been lyophilized or were hydrated and frozen at -10 degrees C. The bridges are also in a time-averaged compact conformation in whole cells at 0 degrees C but with sizable structural fluctuations associated with local mobility. A small fraction of bridges are in extended-chain conformations.

Long-term potentiation in cultures of single hippocampal granule cells: a presynaptic form of plasticity

We have explored the mechanisms of mossy fiber long-term potentiation (LTP) at autapses in single-cell cultures of guinea pig hippocampal dentate granule cells. L-AP4-sensitive, but not insensitive, cells responded to a brief tetanus with a sustained potentiation in the synaptic responses. The induction of this LTP appeared identical to that observed in hippocampal mossy fiber synapses in situ, in that it required a rise in presynaptic Ca2+ and activation of protein kinase A. Its expression also appeared to be presynaptic and was due, at least in part, to events that occurred after the entry of Ca2+ and to the switching on of previously silent release sites.

Juvenile chronic arthritis: radiologic manifestations in the foot and ankle

Juvenile chronic arthritis (JCA) is the most common connective tissue disease affecting the articular structures in children. This paper examines radiographic findings in the foot and ankle of patients with JCA. In addition, the importance of foot and ankle radiographs in distinguishing juvenile-onset ankylosing spondylitis from two other subclasses of JCA are discussed.

A convergent solid-phase synthesis of actinomycin analogues--towards implementation of double-combinatorial chemistry

The actinomycin antibiotics bind to nucleic acids via both intercalation and hydrogen bonding. We found this 'double-action attack' mechanism very attractive in our search for a novel class of nucleic acid binders. A highly convergent, solid-phase synthetic strategy has been developed for a class of peptide-aryl-peptide conjugates modeled upon natural actinomycins. The features of this method include the use of Fmoc solid-phase peptide synthesis, side-chain to side-chain cyclization on the solid phase, a chemoselective cleavage step and segment condensation. The synthetic scheme is consistent with the requirements for combinatorial synthesis and furthermore, the final segment condensation allows, for the first time, double-combinatorial chemistry to be performed where two combinatorial libraries can be reacted with each other.

Beta-adrenergic regulation of synaptic NMDA receptors by cAMP-dependent protein kinase

To identify the protein kinases regulating synaptic NMDA receptors, as well as the conditions favoring enhancement of NMDA receptor-mediated excitatory postsynaptic currents (EPSCs) by phosphorylation, we studied the effects of kinase activation and inhibition in hippocampal neurons. Inhibition of cAMP-dependent protein kinase (PKA) prevented recovery of NMDA receptors from calcineurin-mediated dephosphorylation induced by synaptic activity, suggesting that tonically active PKA phosphorylates receptors during quiescent periods. Conversely, elevation of PKA activity by forskolin, cAMP analogs, or the beta-adrenergic receptor agonists norepinephrine and isoproterenol overcame the ability of calcineurin to depress the amplitude of NMDA EPSCs. Thus, stimulation of beta-adrenergic receptors during excitatory synaptic transmission can increase charge transfer and Ca2+ influx through NMDA receptors.

Interaction between the Escherichia coli Regulatory protein TyrR and DNA: a fluorescence footprinting study

The Escherichia coli regulatory protein TyrR controls the expression of eight transcription units that encode proteins involved in the biosynthesis and transport of aromatic amino acids. It is a homodimer of 57 600 subunit molecular weight and has a binding site for ATP and weak ATPase activity. In the presence of ATP, TyrR binds tyrosine, which induces self-association of TyrR from a dimer to a hexamer. This report examines the interaction of TyrR with a 42 bp DNA oligonucleotide containing a centrally located binding site for TyrR (TyrR box). Replacement of a thymidine residue with an aminouridine residue at positions 7, 9, 13, 15, 19, 22, and 26 from one end of the 42mer enables labeling with fluorescein and successive placement of the label along the major groove of the DNA. The fluorescence footprinting of the oligonucleotide was followed using steady-state and time-resolved fluorescence methods. Binding of the TyrR dimer caused significant changes in the fluorescent properties of the labels attached to positions 13, 15, and 26, suggesting the involvement of these bases in the binding of the protein. Except for the position 15 conjugate, binding of the TyrR dimer caused little change in fluorescence intensity. Therefore, fluorescence anisotropy was used to follow the binding equilibrium. The fluorescence of the position 15 conjugate increased 1.6-fold on binding TyrR, suggesting that the fluorophore was in close contact with the protein. For all conjugates, the addition of tyrosine at the end of the titration with TyrR increased the anisotropy markedly, suggesting that the hexameric form of TyrR could bind the oligonucleotide. Two rotational correlation times were found for the labeled conjugates: one reflecting the motion of the probe at its point of attachment to the DNA (220-290 ps), the other reflecting the global tumbling of the labeled oligonucleotide (14-21 ns). On binding TyrR, changes in the correlation times and their associated amplitudes and changes in the range of angular motion of the probe depended on the position of the label. Evidence is presented that the binding of the TyrR hexamer, but not the TyrR dimer, affects regions that flank the binding sequence. The results support the hypothesis that the binding of the TyrR hexamer is responsible for interaction between tandem TyrR boxes in the tyrR regulon.

Synthesis and characterisation of fluorescent oligonucleotides. Effect of internal labelling on protein recognition

Fluorescently labelled 42 base pair DNA duplexes were synthesised to examine the interaction between the TyR repressor protein of Escherichia coli and its DNA recognition sequence. An Fmoc-protected 5-(3-aminoprop-l-yn-l-yl)-2'-deoxyuridine phosphoramidite was synthesised and incorporated into oligonucleotides using standard beta-cyanoethyl phosphoramidite chemistry. Oligonucleotides containing the 3-aminopropynyl nucleotide at internal positions were reacted with fluorescein isothiocyanate to generate fluorescent DNA molecules useful for characterising interactions between DNA and proteins. Short DNA duplexes were investigated with respect to their melting temperatures and their ability to bind TyrR. Oligonucleotides containing a TyrR binding site were labelled in the central region of the recognition sequence or near the 5' edge of the recognition sequence. Fluorescein-labelled oligonucleotides could hybridise to form duplex DNA, and gel retardation experiments showed that the presence of the dye did not alter the binding affinity for the TyrR protein significantly. Fluorescence anisotropy measurements were used to examine the binding equilibrium in low and high salt buffers. A dissociation constant of 200-500 nM was obtained for the interaction of the TyrR dimer with a 42 bp duplex containing a centrally located 22 bp TyrR binding site.

Synaptic desensitization of NMDA receptors by calcineurin

Desensitization is a phenomenon that is common to many ligand-gated ion channels but has been demonstrated only rarely with physiological stimulation. Numerous studies describe desensitization of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor by exogenous agonists, but whether synaptic stimulation causes desensitization has been unknown. Synaptic stimulation of NMDA receptors on rat hippocampal neurons resulted in desensitization that was prevented by intracellular 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), adenosine-5'-O-(3-thiotriphosphate) (ATP-gamma-S), or inhibitors of phosphatase 2B (calcineurin), but not by inhibitors of phosphatases 1 and 2A or of tyrosine phosphatases. Synaptic NMDA receptors may fluctuate between phosphorylated and dephosphorylated forms, depending on the rate of synaptic stimulation and the magnitude of the associated influx of calcium through NMDA receptors.

[Xin'an Dispensaries and its role in medicine in the Ming-Qing dynasties]

The Xin'an Dispensaries were set up in the Song dynasty, completed in the Ming dynasty and reached its peak of development at the end of the Qing dynasty. The representative ones of the dispensaries include Lu's Baohetang of the Song dynasty, Xu's Baoyuantang, Zhengtian dispensary, and Baoyutang of the Ming dynasty, Hu Xian Chun, Zhongdetang of the Qing dynasty. All these dispensaries were mostly run by the physicians themselves in the Ming dynasty, while they were run by Anhui businessmen in the Qing dynasty. As a union embodying health care, production and trading of traditional handicraft, not a few of them had become famous pharmaceutical factories today, such as Hu Qing Yu Tang, Jianmin Pharmaceutical Factory of Wuhan. Rich experience on production and management were accumulated, alongside achievements on prescription, drug processing, storage, collection and ready-made drug manufacturing.

Block of glutamate transporters potentiates postsynaptic excitation

We have studied the effects of blockers of glutamate transporters on excitatory synaptic transmission to determine whether transporters increase the clearance rate of transmitter from the synaptic cleft on the millisecond time scale. The transporter blockers Li+ and THA increased the amplitude, but not the decay time, of spontaneous miniature AMPA receptor EPSCs recorded at 34 degrees C but not 24 degrees C. Evoked AMPA receptor EPSCs were similarly affected by THA. The rapidly dissociating AMPA receptor competitive antagonist PDA inhibited evoked AMPA receptor EPSCs less in the presence of THA at both temperatures, implying that transporter blockade slows clearance. We suggest that transporters speed glutamate clearance mainly by binding glutamate and that AMPA receptors are not saturated by synaptically released glutamate at 34 degrees C.

Regulation of glycine-insensitive desensitization of the NMDA receptor in outside-out patches

1. Regulation of desensitization of N-methyl-D-aspartate (NMDA) receptors was studied in outside-out patches from cultured rat hippocampal neurons. The progressive increase in a glycine-insensitive form of desensitization after patch excision did not require extracellular Ca2+ concentration nor was it use dependent, but the initial extent of desensitization after patch formation was reduced by intracellular bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA). 2. Preincubation of neurons with 30 microM dantrolene, which can decrease Ca2+ release from intracellular stores, also reduced the degree of NMDA receptor desensitization just after patch excision. Thus the development of this form of desensitization appears to be triggered by a transient increase of intracellular calcium. 3. The extent of glycine-insensitive desensitization was also reduced by intracellular ATP-gamma S, high concentrations of the phosphatase inhibitor, microcystin, or intracellular application of a peptide inhibitor of calcineurin. These data support the hypothesis that glycine-insensitive desensitization of the NMDA receptor in outside-out patches is regulated in part by the phosphorylation state of the receptor or an associated protein. 4. Because the NMDA channel is very permeable to Ca2+, the extent of phosphorylation and thus desensitization of the receptors may be sensitive to synaptic activation and could serve as a feedback mechanism to decrease the intensity of excitation and plasticity.

Multivesicular release from excitatory synapses of cultured hippocampal neurons

Release of neurotransmitter from presynaptic terminals occurs by exocytosis of vesicular contents into the synaptic cleft. We find that more than one quantum of transmitter can interact with the same population of postsynaptic NMDA receptors in conditions which increase the probability of transmitter release. Increasing release probability also results in proportional increases in both AMPA and NMDA receptor components of the synaptic current. These results suggest that the fraction of AMPA and NMDA receptors occupied by transmitter following the release of a single quantum is similar. Based on AMPA and NMDA receptor responses of outside-out patches to short applications of glutamate, we suggest that both receptor types may be saturated normally by synaptic release.

A false transmitter at excitatory synapses

We used the low affinity N-methyl-D-aspartate (NMDA) receptor agonist D-glutamate to study the time course of synaptic activation of NMDA receptors. Repetitive stimulation of cultured hippocampal neurons loaded with D-glutamate caused a dramatic shortening of both the rising and decaying phases of NMDA receptor excitatory postsynaptic currents (EPSCs) evoked by autaptic stimulation. The EPSC time course was mimicked by NMDA receptor currents evoked in outside-out patches by 1-4 ms applications of D-glutamate. Thus, D-glutamate can be released as a false transmitter. The results show that both the rise and fall of the NMDA receptor EPSCs are normally controlled by the slow unbinding rate of the natural neurotransmitter and that the concentration of free transmitter is elevated in the cleft for only a few milliseconds after release.

Interactions between the glycine and glutamate binding sites of the NMDA receptor

The interactions between the glycine and glutamate binding sites of the NMDA receptor have been studied in outside-out patches and synapses from hippocampal neurons in culture using rapid drug application techniques. Desensitization of NMDA receptor-mediated currents elicited by glutamate in newly excised outside-out patches was reduced in the presence of saturating concentrations of glycine. This suggests that the glutamate and glycine binding sites of the NMDA receptor are allosterically coupled as has been reported in whole-cell preparations. A glycine-insensitive form of desensitization increased rapidly over the first few minutes of recording and largely occluded the glycine concentration-sensitive desensitization in outside-out patches. However, even in old patches that displayed no glycine-sensitive desensitization, the unbinding rate of glycine was increased fourfold by the presence of glutamate, suggesting that the two binding sites were still allosterically coupled. These data suggest the existence of two forms of NMDA receptor desensitization in outside-out patches, only one of which is dependent on the concentration of glycine. In the presence of saturating levels of glycine, activation of NMDA receptors by synaptic stimulation or by exogenous glutamate resulted in currents that relaxed biexponentially. Addition of the partial glycine-site agonist 1-hydroxy-3-aminopyrrolid-2-one (HA-966) increased the rate of decay of both synaptic and patch currents. This suggests that HA-966 increases the dissociation rate of glutamate from NMDA receptors. These results support the hypothesis that the glutamate and glycine binding sites of NMDA receptors interact allosterically; ligand binding at both types of sites can affect the affinity of the other type for its agonist.