Transmembrane chloride currents in human atrial myocytes

The present study was designed to evaluate the presence of basal, swelling-induced, and cAMP-dependent Cl- currents in human atrial myocytes studied with the whole cell patch-clamp technique. Under basal conditions, a small outwardly rectifying background conductance was noted that reversed close to 0 mV and was not altered by Cl- replacement. Isoproterenol (1 microM), forskolin (3 microM), and 8-bromoadenosine 3',5'-cyclic monophosphate (50 microM) did not increase membrane conductance, even when responsiveness to isoproterenol was confirmed by an increase in Ca2+ current and when perforated-patch techniques (nystatin) were used. Exposure to hyposmotic solutions increased cell volume and induced a whole cell conductance that showed outward rectification, was inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (100 microM), and responded to changes in Cl- gradient in a fashion consistent with a Cl(-)-selective conductance, with estimated relative permeabilities of 1, 0.25, and 0.07 for Cl-, methanesulfonate, and aspartate, respectively. The results suggest that human atrial cells lack basal and adenosine 3',5'-cyclic monophosphate-dependent Cl- current but manifest a substantial Cl- conductance in the presence of cell swelling.

Effects of in vivo treatments of nicotine and benzo[a]pyrene on the epidermal growth factor receptor in hamster buccal pouch

This study was conducted to investigate the effects of two major ingredients in cigarette smoke, benzo-alpha-pyrene (BP) and nicotine (Nic), on epidermal growth factor (EGF) receptor in hamster buccal pouch. Adult male Syrian hamsters were treated by apically swabbing the buccal pouch with mineral oil (Control), 0.5 microgram/ml of BP, Nic or BP+Nic in mineral oil, twice a day, 5 days a week for 4 weeks. The BP+Nic treatment resulted in a significant reduction of submandibular gland (SG) EGF (Control vs. BP+Nic, 6.93 +/- 1.31 vs. 4.77 +/- 0.26* ng/g wet tissue, mean +/- S.D., n=5,*P < 0.05). Treatment with BP or Nic also caused a reduction, although not statistically significant, of EGF in SG extract. For the receptor study, all treatments significantly increased [125I]EGF binding to membrane preparations of buccal pouch as compared to Control (Control, BP, Nic, BP+Nic; 12.2 +/- 0.9, 20.5 +/- 2.2*, 17.0 +/- 1.3*, 21.2 +/= 1.6* fmol/mg prot. (mean +/- S.E.M.), n=5, P < 0.05). Scatchard analysis revealed that the higher EGF binding to the BP+Nic-treated sample was due to the higher number of receptors, but not higher affinity. Data from protein kinase study indicate that EGF stimulated phosphorylation of 170- and 150-kDa proteins in buccal membrane preparations. Treatment of BP+Nic resulted in reductions in EGF-stimulated phosphorylation of 170- and 150-kDa proteins by 19 and 72%, respectively. The present study has established an animal model which will benefit investigation of the mechanism by which tobacco alters the EGF receptor in oral buccal mucosa.

Bi-directional dideoxy fingerprinting (Bi-ddF): a rapid method for quantitative detection of mutations in genomic regions of 300-600 bp

There is a great need for rapid screening methods that detect essentially all mutations. Dideoxy fingerprinting (ddF) is a highly sensitive screening method that is performed by electrophoresing one lane of a Sanger dideoxy termination reaction through a nondenaturing gel. Mutations may produce an extra segment or eliminate a segment from the termination products (informative dideoxy component). In addition, mutations can be detected by the altered mobility of one or more termination segments (informative SSCP component). To screen larger segments with virtually 100% sensitivity, bi-directional ddF (Bi-ddF) was developed. Bi-ddF is a 'second generation ddF' in which the dideoxy termination reaction is performed simultaneously with two opposing primers. Bi-ddF has two important advantages over ddF: (i) the dideoxy component can detect 10 of the 12 types of possible single-base substitutions; and (ii) the SSCP component is enhanced because alterations of mobility can be detected in either the downstream or upstream direction. As a result, Bi-ddF can screen larger regions of genomic DNA with virtually 100% sensitivity. Bi-ddF detected 100% of 28 single-base substitutions in a 494 bp segment containing exons B and C of the human factor IX gene and 100% of 42 single-base substitutions and one microdeletion present in a 577 bp region containing exon H. In a blinded analysis in which 39 wildtype samples were randomly mixed with 51 mutant samples, all mutations were detected with no false positives. Bi-ddF requires essentially the same effort as ddF, yet twofold more DNA sequence can be screened reliably per unit effort.

Decreased levels of salivary prostaglandin E2 and epidermal growth factor in recurrent aphthous stomatitis

Prostaglandin E2 and epidermal growth factor are two important cytoprotective compounds in saliva. This study investigated their salivary levels in controls and individuals with minor recurrent aphthous stomatitis. The development of recurrent aphthous stomatitis was divided into three stages: (1) early active stage (mucosal redness); (2) active stage (mucosal ulceration); (3) convalescent stage. Unstimulated mixed saliva was collected from each volunteer. Salivary prostaglandin E2 and epidermal growth factor concentrations were determined by radioimmunoassay. Their levels (mean +/- SEM) were significantly lower during the active stage of ulceration as compared to the control: (a) for prostaglandin E2, 200 +/- 55 versus 73 +/- 11 pg/mg salivary protein (p < 0.01), 447 +/- 123 versus 112 +/- 19 pg/ml saliva (p < 0.01), 215 +/- 30 versus 63 +/- 12 pg/min salivary flow (p < 0.01), control (n = 12) versus active stage (n = 15); (b) for epidermal growth factor, 1.09 +/- 0.17 versus 0.67 +/- 0.17 ng/mg salivary protein (p < 0.05); 2.51 +/- 0.53 versus 0.84 +/- 0.19 pg/ml saliva (p < 0.05), 1.24 +/- 0.26 versus 0.41 +/- 0.09 pg/min salivary flow (p < 0.05), control (n = 12) versus active stage (n = 12). Salivary prostaglandin E2 and epidermal growth factor showed stage-dependent alterations during the development of the stomatitis. The prostaglandin E2 concentration decreased significantly during the active stage of ulceration, and then increased significantly during the convalescent stage. However, the recovery of salivary epidermal growth factor after the ulceration was slower than that of the prostaglandin E2. It is suggested that the diminution of prostaglandin E2 and epidermal growth factor in the saliva may be associated with the ulcer development.

[Preoperative embolization of paraganglioma in head and neck]

Preoperative embolization of 10 cases of paraganglioma in carotid artery body and jugular foramen region via endovascular approach was performed. Tumor vessels were obliterated 100% in 7 cases and 80% - 90% in 3 cases as was demonstrated by angiography. It is available for us to reduce bleeding, expose tumor, avoid the iatrogenic damage of the important vessels and nerves around tumor during operation and to total resection possible. Additionally, the manipulating points of embolization are discussed.

Repression of the Klebsiella aerogenes nac promoter

Transcription of the nitrogen-regulated nac promoter of Klebsiella aerogenes requires sigma54 RNA polymerase, is activated by the phosphorylated form of the transcription factor nitrogen regulator I (NRI) (NtrC), and is repressed by the product of the nac gene, Nac. Nac protects a large portion of the nac control region, extending from positions -130 to -70, from digestion by DNase I. This site(s) lies immediately upstream from the site at which sigma 54 RNA polymerase binds, is downstream of a high-affinity binding site for the transcriptional activator NRI approximately P, and partially overlaps a low-affinity NRI approximately P-binding site. Binding of Nac to the DNA resulted in bending of the DNA but did not interfere with the binding of sigma 54 RNA polymerase to the promoter or with the binding of NRI approximately P to either the high-affinity site or low-affinity site. Furthermore, transcription assays with various wild-type and mutant templates suggested that Nac did not exclude NRI approximately P from either the low- or high-affinity sites, nor did Nac interfere with the ability of the polymerase to form the open complex when the binding sites for NRI approximately P were moved to different locations upstream from the promoter. Rather, Nac seemed to repress by an antiactivation mechanism in which the interaction of the NRI approximately P, bound at its normal sites, with sigma 54 RNA polymerase, bound to the promoter, was prevented.

Activation of transcription initiation from the nac promoter of Klebsiella aerogenes

The nac gene of Klebsiella aerogenes encodes a bifunctional transcription factor that activates or represses the expression of several operons under conditions of nitrogen limitation. In experiments with purified components, transcription from the nac promoter was initiated by sigma 54 RNA polymerase and was activated by the phosphorylated form of nitrogen regulator I (NRI) (NtrC). The activation of the nac promoter required a higher concentration of NRI approximately P than did the activation of the Escherichia coli glnAp2 promoter, and both the promoter and upstream enhancer element contributed to this difference. The nac promoter had a lower affinity for sigma 54 RNA polymerase than did glnAp2, and uninitiated competitor-resistant transcription complexes formed at the nac promoter decayed to competitor-sensitive complexes at a greater rate than did similar complexes formed at the glnAp2 promoter. The nac enhancer, consisting of a single high-affinity NRI-binding site and an adjacent site with low affinity for NRI, was less efficient in stimulating transcription than was the glnA enhancer, which consists of two adjacent high-affinity NRI-binding sites. When these binding sites were exchanged, transcription from the nac promoter was increased and transcription from the glnAp2 promoter was decreased at low concentrations of NRI approximately P. Another indication of the difference in the efficiency of these enhancers is that although activation of a nac promoter construct containing the glnA enhancer was relatively insensitive to subtle alterations in the position of these sites relative to the position of the promoter, activation of the natural nac promoter or a nac promoter construct containing only a single high-affinity NRI approximately P binding site was strongly affected by subtle alterations in the position of the NRI approximately P binding site(s), indicating a face-of-the-helix dependency for activation.

Effect of antihydatid drugs on carbohydrate metabolism of metacestode of echinococcus granulosus

A biochemical some enzymes of glycolysis and a partial reversed tricarboxylic acid cycle together with hydrolytic enzymes in the cyst wall of Echinococcus granulosus was carried out. Lactate dehydrogenase (LDH), pyruvate kinase (PK), phosphoenolpyruvate carboxykinase (PEPCK), and adenosine triphosphatase (ATPase) showed their high level of activity, suggesting that the proliferation of E. granulosus cyst wall is an energy-dependent process and the major pathways for glucose metabolism is glycolysis. Treatment of E. granulosus-infected mice with mebendazole and albendazole resulted in marked inhibition of PK, PEPCK and ATPase of E. granulosus cyst wall, whereas praziquantel had no effect, indicating that PK, PEPCK, and ATPase might be chemotherapeutic targets and the differences in the inhibitory effects might account for the efficacy of the three antihydatid drugs.

The RNA component of human telomerase

Eukaryotic chromosomes are capped with repetitive telomere sequences that protect the ends from damage and rearrangements. Telomere repeats are synthesized by telomerase, a ribonucleic acid (RNA)-protein complex. Here, the cloning of the RNA component of human telomerase, termed hTR, is described. The template region of hTR encompasses 11 nucleotides (5'-CUAACCCUAAC) complementary to the human telomere sequence (TTAGGG)n. Germline tissues and tumor cell lines expressed more hTR than normal somatic cells and tissues, which have no detectable telomerase activity. Human cell lines that expressed hTR mutated in the template region generated the predicted mutant telomerase activity. HeLa cells transfected with an antisense hTR lost telomeric DNA and began to die after 23 to 26 doublings. Thus, human telomerase is a critical enzyme for the long-term proliferation of immortal tumor cells.

Cataloging altered gene expression in young and senescent cells using enhanced differential display

Recently, a novel PCR-based technique, differential display (DD), has facilitated the study of differentially expressed genes at the mRNA level. We report here an improved version of DD, which we call Enhanced Differential Display (EDD). We have modified the technique to enhance reproducibility and to facilitate sequencing and cloning. Using EDD, we have generated and verified a catalog of genes that are differentially expressed between young and senescent human diploid fibroblasts (HDF). From 168 genetags that were identified initially, 84 could be sequenced directly from PCR amplified bands. These sequences represent 27 known genes and 37 novel genes. By Northern blot analysis we have confirmed the differential expression of a total of 23 genes (12 known, 11 novel), while 19 (seven known, 12 novel) did not show differential expression. Several of the known genes were previously observed by others to be differentially expressed between young and senescent fibroblasts, thereby validating the technique.

Comparative mechanisms of 4-aminopyridine-resistant Ito in human and rabbit atrial myocytes

The cardiac transient outward current (Ito) has been shown in several species to consist of two components: 1) a 4-aminopyridine (4-AP)-sensitive component (Ito1) and 2) a 4-AP-resistant component (Ito2). In rabbits, Ito2 is a Ca(2+)-dependent Cl- current [ICl(Ca)]; similar mechanisms have been suggested to underlie Ito2 in human atrium. We used whole cell patch-clamp techniques to define the mechanism of Ito2 (defined as the component resistant to 5 mM 4-AP) in human atrial myocytes, with parallel experiments performed in rabbit atrial cells. In rabbit atrium, Ito2 activated more slowly than Ito1 and had a bell-shaped current-voltage of Ito with properties similar to Ito2 in the rabbit, and a similar component recorded with pipette K+ replaced by Cs+ was suppressed by the substitution of methanesulfonate for Cl- in the superfusate. In human cells, a 4-AP-resistant Ito2 was recorded at a depolarizing pulse frequency of 1 Hz, but not at 0.1 Hz. Ito2 activated rapidly and inactivated earlier than Ito1, whereas its I-V relation was linear like that of Ito1. Ryanodine had no effect on human atrial Ito. When K(+)-free pipette solutions were used, no Ito was recorded in 30 human atrial myocytes, and external Cl- replacement with methanesulfonate failed to reveal an Ito. In 13 human myocytes, isoproterenol increased ICa but failed to activate an Ito compatible with ICl(Ca). Whereas caffeine suppressed human atrial Ito, it also suppressed Ito1 [in the presence of 200 microM Cd2+ to block ICa and 5 mM intracellular ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to buffer intracellular Ca2+] in both human and rabbit atrium, indicating an action unrelated to Ca(2+)-triggered Ca2+ release. In conclusion, we were unable to demonstrate the presence of ICl(Ca) in human atrial myocytes, and the 4-AP-resistant component of Ito appeared to be due to 4-AP unblocking.

Idiopathic atrial fibrillation in dogs: electrophysiologic determinants and mechanisms of antiarrhythmic action of flecainide

OBJECTIVES

This study sought to determine the mechanisms of idiopathic atrial fibrillation and the atrial antifibrillatory action of flecainide in dogs.

BACKGROUND

In a small subset of dogs, sustained atrial fibrillation can be readily induced in the absence of vagal tone. The electrophysiologic mechanisms underlying this ability to sustain atrial fibrillation, and of flecainide action on the arrhythmia, are unknown.

METHODS

Six dogs with inducible sustained atrial fibrillation were studied before and after flecainide administration and compared with a control group of 10 dogs.

RESULTS

Dogs with atrial fibrillation differed in displaying more shortening of the atrial refractory period with increased rate, resulting in a significantly shorter refractory period and wavelength for reentry at rapid rates, and in increased regional dispersion in refractoriness. Activation maps during sustained fibrillation showed a mean (+/- SE) of 6.3 +/- 0.4 coexistent zones of reentry, compatible with short wavelengths, whereas in control dogs activation during self-limited atrial fibrillation was better organized, and the number of reentrant circuits was smaller. Quantitative analysis demonstrated significantly greater inhomogeneity of activation during atrial fibrillation in dogs with atrial fibrillation than in control animals. Flecainide terminated atrial fibrillation by increasing the duration and homogeneity of atrial refractoriness at rapid rates, thereby reducing the number of reentry circuits and the heterogeneity of activation.

CONCLUSIONS

The ability of atrial fibrillation to sustain itself resulted from enhanced rate-dependent shortening of atrial refractoriness and increased regional heterogeneity. Flecainide reversed these changes and restored sinus rhythm. These results suggest potential mechanisms of idiopathic atrial fibrillation and are pertinent to understanding the clinical actions of flecainide.

Selective effects of alfentanil on nociceptive-related neurotransmission in neonatal rat spinal cord

We have examined the effects of alfentanil on nociceptive-related neurotransmission in isolated neonatal rat spinal cord, with particular attention to acute tolerance. Electrical stimulation of a lumbar dorsal root was used to evoke the monosynaptic reflex (MSR), a slow ventral root potential (sVRP), and the dorsal root potential (DRP). Alfentanil (0.5 nmol litre-1 to 1 mumol litre-1) depressed sVRP area by a maximum of 85%; EC50 was approximately 2 nmol litre-1. The effects of alfentanil were selective for very slow, metabotropically mediated sVRP components compared with faster NMDA receptor-mediated components. The MSR was unaffected. Alfentanil depressed DRP area by a maximum of 50% at 1 mumol litre-1. Naloxone antagonized all alfentanil effects. Morphine depressed sVRP area with an approximate EC50 of 90 nmol litre-1, giving an alfentanil:morphine potency ratio of 45:1. The effects of alfentanil on sVRP showed no biphasic time dependence up to 60 min. Naloxone administered after alfentanil produced a significant rebound in sVRP area to a level of 143 (SD 21.3)% above control. Thus, in this study there was no evidence for acute tolerance, as measured by a decrease in effectiveness over time, but there was evidence as measured by rebound following naloxone.

Reactivity of monoclonal antibodies established against a recombinant human endogenous retrovirus-K (HERV-K) envelope protein

Human endogenous retroviruses (HERVs) are widely believed to represent possible pathogenic agents in autoimmune disorders and carcinogenesis. We generated 2 monoclonal antibodies (mAbs) against a recombinant HERV-K outer-membrane envelope protein. These mAbs were capable of immunoprecipitating protein bands of 55, 51 and 45 kDa, respectively, from [35S]methionine-labeled lysates of T47D (human breast carcinoma), Raji, Bjab (both human beta-lymphoblastoid) and H9 (human T-cell lymphoma) cells. Furthermore, the 55 kDa band could be precipitated from cell-free supernatant of biosynthetically labeled T47D cells, indicating that this molecule may be secreted. Indirect immunofluorescence and subsequent FACS analysis demonstrated the presence of these molecules on T47D, HeLa, Raji, Bjab and H9 cells as well as on lymphocytes isolated from tonsils and stimulated with poke weed mitogen (PWM). Due to the broad distribution and lack of detection of HERV-K-env mRNA in these cells, we believe that these antigens are of cellular origin detected by crossreactivity of mAbs against HERV-K-env protein with cellular molecules.

Contribution of ATP-sensitive potassium channels to the electrophysiological effects of adenosine in guinea-pig atrial cells

1. Adenosine caused dose-dependent action potential abbreviation in multicellular guinea-pig atrial preparations, an action antagonized by glyburide (IC50, 31 microM) in both physiological and low-chloride superfusate. 2. When 5 mM ATP was included in pipettes for whole-cell voltage clamp of isolated guinea-pig atrial myocytes, adenosine (10 microM) increased the holding current at -40 mV from 41 +/- 8 to 246 +/- 31 pA (mean +/- S.E.M., P < 0.01), and glyburide (20 microM) returned the holding current to 69 +/- 11 pA (P < 0.01 vs. adenosine alone). Acetylcholine (10 microM) also increased the holding current, but its effects were not altered by glyburide. 3. Both adenosine and acetylcholine induced an additional current component in response to 500 ms voltage steps. Glyburide partially inhibited the adenosine-induced current, but did not alter the effect of acetylcholine. In the presence of maximally effective acetylcholine concentrations, adenosine increased membrane conductance (P < 0.01), although to a lesser extent than in the absence of acetylcholine. 4. Single K+ channel activity was seen in only one of eight cell-attached patches in the absence of adenosine or acetylcholine (0.5 mM Ba2+ in bath and pipette solutions). With acetylcholine (10 microM) in the pipette, inwardly rectifying channels (conductance, 41 +/- 5 pS) were seen in five of six patches. With adenosine (10 microM) in the pipette, single-channel activity was seen in twelve of fourteen patches with two populations of channels, one similar to that induced by acetylcholine and another higher-conductance channel (72 +/- 5 pS) that showed less inward rectification. Glyburide (20 microM) suppressed the high-conductance channel (68 +/- 2 pS) leaving a single channel type with a conductance of 36 +/- 5 pS and strong inward rectification. 5. We conclude that K+ATP channels contribute to the electrophysiological actions of adenosine on guinea-pig atrium in the presence of physiological intracellular ATP levels, and may therefore play a role in the cardiac electrophysiological effects of adenosine in the absence of myocardial ischaemia.

Role of chloride currents in repolarizing rabbit atrial myocytes

Rabbit atrial cells manifest a prominent transient outward K+ current (Ito1), but this current recovers slowly from inactivation and is unlikely to be important at physiological rates (3-5 Hz). Depolarization of rabbit atrial cells also elicits a transient Ca(2+)-dependent outward Cl- current (Ito2). To compare the relative magnitude of these transient outward currents at various rates, we applied whole cell voltage-clamp techniques to isolated rabbit atrial myocytes. Whereas peak Ito1 exceeded Ito2 at slow rates (0.1 Hz), Ito1 was strongly reduced as rate was increased (by 97 +/- 2%, mean +/- SE, at 4 Hz), while Ito2 was slightly reduced (by 28 +/- 4%, 4 Hz). The reversal potential of transient outward tail currents at 0.07 Hz was -49 +/- 9 mV, while at 2.5 Hz the reversal potential became -18 +/- 7 mV (calculated Cl- reversal potential -18 mV). The addition of the Cl- transport blocker 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS; 150 microM) or the replacement of external Cl- with methanesulfonate inhibited a large part of the transient outward current elicited by depolarization at 4 Hz. DIDS and Cl- replacement increased action potential duration in both single rabbit atrial cells and multicellular rabbit atrial preparations. We conclude that the Ca(2+)-dependent Cl- current is substantially larger than the transient K+ current at physiological rates in the rabbit and is likely to play a more important role in action potential repolarization than the latter current in this tissue in vivo.

N-methyl-D-aspartate receptors are implicated in hyperresponsiveness following naloxone reversal of alfentanil in isolated rat spinal cord

In isolated neonatal rat spinal cord, naloxone administered after an opioid increases a nociceptive-related slow ventral root potential (sVRP) to levels above pre-drug controls. We studied the role of N-methyl-D-aspartate (NMDA) receptors in this phenomenon, which may be related to acute tolerance and to hyperalgesia on antagonist-precipitated withdrawal. Naloxone (200 nM) alone produced no significant effect on sVRP area, while naloxone (560 nM) increased area to 121 +/- 17.7% of control (mean +/- SD). Following 200 nM alfentanil, naloxone (200 nM) was associated with a significant rebound in sVRP area to 138 +/- 18.0% of pre-drug control. Hyperresponsiveness developed within 7 min of initial alfentanil exposure. The non-competitive NMDA antagonist MK-801 (20 nM) had no effect on sVRP area when applied alone; higher concentrations produced irreversible depression. MK-801 (20 nM) co-applied with 200 nM alfentanil blocked the rebound increase in sVRP area following naloxone 200 nM and also the increase following naloxone alone (560 nM). The results suggest that alfentanil induces a rapid NMDA receptor-dependent change in spinal cord neuronal excitability.

The relationship between secondary chromosomal abnormalities and blast transformation in chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) is a stem cell disorder which progresses from a chronic phase (CP) to an accelerated phase (AP), and/or a blast phase (BP) of myeloid (M) or lymphoid (L) phenotype. This progression is frequently preceded or accompanied by recurring secondary chromosomal abnormalities which are believed to play a role in the transformation. In order to investigate the relationship between the secondary change and the development of BP, we undertook a study using fluorescence in situ hybridization to determine in which cells the secondary abnormalities were present. We observed that in one case of L-BP, the secondary change (trisomy 8) appeared to be in a subclone that was different from the blast cells, as it was absent from the lymphoblasts but present in differentiating erythroid, monocytic and granulocytic cells. In two cases, the secondary change (trisomy 8, extra Ph) probably occurred prior to an acute transforming event as it was present in CP or AP predominantly in differentiated granulocytic or monocytic cells. In one case of M-BP, the secondary change (trisomy 8) probably occurred after the acute transformation, as it appeared in only a subset of the blasts. Lastly, in four cases of L-BP, the secondary change (monosomy 7, extra Ph or hyperdiploidy) was closely associated with the BP as it was present in all of the blasts. The findings indicate that some secondary abnormalities may be directly related to the development of BP and may provide clues to the identity of genes responsible for the acute phase transition. Other abnormalities occurring before, or after the acute transformation or in a different subclone from the acute phase blasts, may be more important for denoting genomic instability than for helping to understand the mechanism of blast transformation.

[Observation of immune effect of 5 kinds of Denmark II lyophilized vaccines]

This paper reported five kinds of Denmark II lyophilized vaccines produced by 5 different biological production institutes. Through the double blind randomized trial in newborns after 1 year observation, the results demonstrated that all vaccines possessed the stability of heat tolerance and the 12 week tuberculin conversion rates of all group exceeded to 95%, and 1-year positive maintenance rates were in the range of 88.3%-96.1%, and the average diameter of induration was relatively large; the local reaction belonged to normal range; the swollen-lymph node rate was not high; the immune effect was satisfactory.