A four-day study to evaluate the anti-plaque efficacy of an experimental triclosan-containing dentifrice

Four-day, non-brushing studies have been used successfully to demonstrate the anti-plaque efficacy of triclosan-containing dentifrices. The treatment effects observed are variable, likely due to differences in formulation, study design and measurement techniques. This randomized, double-blind crossover study was conducted to evaluate the anti-plaque efficacy of an experimental, multiple-benefit, triclosan-containing dentifrice versus two currently marketed sodium fluoride dentifrices in a four-day, lingual-brushing model on subjects in Beijing. People's Republic of China. Subjects brushed the lingual surfaces for 30 seconds, and before expectorating, swished the saliva/dentifrice slurry over the buccal surfaces for an additional 30 seconds. This procedure was repeated. Subjects performed their assigned brushing regimen twice daily for four days under supervision. On Day 5, plaque was measured using the Turesky Modification of the Quigley-Hein Plaque Index. There were highly significant treatment effects in favor of the experimental triclosan-containing dentifrice for whole mouth, buccal and lingual sites when compared to either of the sodium fluoride dentifrices (p < 0.0001).

[Structure determination of the constituents from Citrus grandis Osbeck]

OBJECTIVE

To isolate the chemical constituents of the peelings of Citrus grandis and determine their structure.

METHOD

Column chromatography and PTLC were applied to isolating and purifying the chemical constituents, and 1H NMR and 13C NMR were used to elucidate their structure.

RESULT

4 compounds were isolated as meranzin hydrate(1), roseoside(2), 8-(3-beta-D-syl-2-hydrox-3-methylbutyl)-7-methoxycoumarin(3) and glucose(4).

CONCLUSION

Compound 2 was isolated as a carotenoid from this genus for the first time.

Biflavonoids from the aerial part of Stephania tetrandra

Investigation of the aerial part of Stephania tetrandra led to the isolation of two biflavonoids, stephaflavone A and stephaflavone B, with a 3-6" linkage pattern, together with beta-sitosterol. Their structures were established on the basis of their spectroscopic data and their physicochemical properties.

[Pathogens of transmitted disease in the pathogenesis of acute pelvic inflammatory disease]

OBJECTIVE

To study the pathogenesis of pathogens of sexually transmitted disease (STD) in acute pelvic inflammatory disease (PID).

METHODS

Neisseria gonorrhoeae, chlamydia trchomatis, ureaplasma urealyticum were cutured respectively in 130 patients with acute PID.

RESULTS

The pathogens of STD had been found in 55 patients. The detective rate of Neisseria gonorrhoeae was 6.9% (9/130), about half of them were mixed infection; the detective rate of chlamydia trachomatis was 4.6% (6/130), all of them were mixed infection; the positive percentage of ureaplasma urealyticum was 37.7% (49/130), one third of them were mixed infection.

CONCLUSION

The pathogens of STD might cause acute PID or only play a synergetic role in it.

Cloning and characterization of human erythroid membrane-associated protein, human ERMAP

We describe here the cloning and characterization of the human gene ERMAP, identified by subtractive hybridization using early and late gestation human fetal liver. By in situ hybridization, we found human ERMAP to be expressed not only in erythoid cells in fetal liver and adult bone marrow, but also in reticulocytes and circulating erythroblasts in 8-12-week fetal cord blood. The human ERMAP protein is predicted to contain a transmembrane segment and one extracellular immunoglobulin fold (IgV). The cytoplasmic region contains a highly conserved B30.2 motif, multiple consensus sequences for kinases, and post-Golgi sorting signals. The protein was localized to the cell surface as shown by an antibody specific for a peptide predicted from the IgV fold. The amino acid sequence of human ERMAP is highly homologous with that of mouse ERMAP, but differs in the number of extracellular immunoglobulin folds. Human ERMAP represents a new unique member of the rapidly growing B30.2 domain proteins.

Triterpenoid saponins from leaves and stems of Panax quinquefolium L

In the chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L., two new minor dammarane saponins, quinquenoside L1 (1) and L2 (2) have been isolated. By means of physico-chemical evidences and spectral analysis their structures were established as 3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-dammara-23,25-diene-3beta, 12beta, 20(S)-triol (1) and 3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-(24Z)-dammar-24-ene-3beta, 12beta, 20(S), 26-tetraol (2).

Quinquenoside L9 from leaves and stems of Panax quinquefolium L

During additional chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L, a new minor dammarane saponin, quinquenoside L9 (1) has been obtained. By means of physico-chemical evidences and spectral analysis, its structure was elucidated 6-O-[alpha-L-rhamnopyranosyl-(1-2)-beta-D-glucopyranosyl]-dammara-3beta, 6beta,12beta,20(S),24zeta,25-hexaol (1).

[Clinical and radiographic evaluation of 108 dental implants after 1-year loading]

OBJECTIVE

To evaluate the clinical outcomes and a possible correlation between peri-implant mucosal inflammation and marginal bone loss in a group of Chinese patients who received IMZ and Frialit-2 implants one year after restoration.

METHODS

The clinical and radiography parameters of 108 IMZ and Frialit-2 dental implants in 70 patients were measured.

RESULTS

There were no signs of mobility and peri-implant radiolucencies in any of the implants. The average bone loss adjacent to implants was (0.63 +/- 0.78) mm. The prevalence of peri-implant mucosal inflammation, as indicated by suclus bleeding index (SBI) of 1.0 or more, was 32.9%. Significant correlation was found between mucosal inflammation and bone loss. The severely inflamed sites experienced greater bone loss than that of healthy or slightly inflamed sites (P < 0.05). In 92% of sites, plaque index (PLI) of more than 1 was measured on implant surfaces. The periodontal status of the remaining natural teeth in each subject was evaluated using the community periodontal index of treatment need (CPITN). Of the 70 examined patients, 15 patients needed oral hygiene instruction, 44 needed scaling and root planing, 8 patients needed periodontal surgical therapy, and only 3 did not need any periodontal treatment.

CONCLUSIONS

The 1-year outcomes from this patient series indicated that IMZ and Frialit-2 implant provide satisfactory clinical results. One of the etiologic factors of alveolar bone loss around implants seems to be plaque-associated marginal inflammation. Improvement of oral hygiene, elimination of marginal tissue inflammation, and proper treatment of periodontal disease of natural teeth are needed for maintaining the implants in these observed subjects.

Peri-implant mucosal inflammation and bone loss: clinical and radiographic evaluation of 108 dental implants after 1-year loading

OBJECTIVE

To evaluate the clinical outcomes, and a possible correlation between peri-implant mucosal inflammation and marginal bone loss, 1 year after restoration in a group of Chinese patients with dental implants.

METHODS

Observation of the clinical and radiographic parameters of 108 IMZ and Frialit-2 dental implants in 70 patients.

RESULTS

One year after loading, there were no signs of mobility and peri-implant radiolucency in any of the implants. The average bone loss adjacent to implants was 0.63 mm (SD 0.78). The prevalence of peri-implant mucosal inflammation, as indicated by sulcus bleeding index (SBI) of 1.0 or more, was 32.9%. Significant positive correlation was found between mucosal inflammation and bone loss (P < 0.05). 92% of the observed sites had plaque index (PLI) scores greater than 1.

CONCLUSIONS

The 1-year outcomes from this patient group indicate that IMZ and Frialit-2 implants provide satisfactory clinical results. One of the etiologic factors of alveolar bone loss around implants seems to be plaque-associated marginal inflammation. Improvement of oral hygiene, elimination of soft tissue inflammation, and proper treatment of periodontal disease of natural teeth are critical for maintaining the implants.

[A one-year study on enzyme level in gingival crevicular fluid around osseointegrated dental implants]

OBJECTIVE

To investigate the changes of gingival crevicular fluid(GCF) volume, aspartate aminotransferase (AST) and alkaline phosphatase(ALP) levels in GCF around dental implants during the first year after rehabilitation. And to explore the relationships between these changes and peri-implant inflammation as well as bone loss.

METHODS

26 Branemark implants in 12 adults were included in this study. Examinations were carried out in a total of 52 sites in preinsertion period and 3, 6, 12 months following rehabilitation.

RESULTS

GCF volume, GCF-AST, GCF-ALP were firstly increased and then fallen during the first year after rehabilitation. GCF volume, GCF-AST, GCF-ALP in sites with peri-implant mucositis were higher than those in health sites, and were increased with the severity of peri-implant mucositis. GCF volume, GCF-AST, GCF-ALP in sites with bone loss were significantly higher than those without bone loss.

CONCLUSION

GCF volume, GCF-AST, GCF-ALP could reflect peri-implant inflammation and bone changes to some degree.

Common elements of spiroplasma plectroviruses revealed by nucleotide sequence of SVTS2

DNA of SpV1-like spiroplasma plectroviruses (rods with single-stranded circular DNA) is scattered in the genome of the phytopathogen Spiroplasma citri and has significant consequences for evolution of the S. citri genome. We determined the complete nucleotide sequence of SVTS2, a SpV1-like virus of S. melliferum, a honeybee pathogen, to ascertain, by comparison with S. citri SpV1 viruses (GenBank U28974 and X51344), the defining features of this important group. The 6,824 nt DNA contains nine ORFs homologous to ORFs of S. citri SpV1 viruses and five ORFs unique to SVTS2. The predicted amino acid sequences of the homologous ORFs were 17-38% identical to those of their S. citri counterparts. The SVTS2 predicted ORF 1 product (Mr 47,031) was considerably smaller than those of known S. citri SpV1 viruses. Also, in contrast to those viruses, SVTS2 lacked an ORF with recognizable similarity to a transposase. ORF 2 of all three viruses had a homologue among the products of genes of MVL-1, a virus of Acholeplasma laidlawii, another plectrovirus. The results suggest that, at most, only slightly more than half of SpV1 genomes consists of genes shared by all spiroplasma viruses of the group.

[Surgical techniques to deal with lens nucleus' fragment of posterior capsular rupture during the phacoemulsification]

OBJECTIVE

To investigate some surgical techniques in dealing with a impending dropped nucleus when posterior capsular rupture during the phacoemulsification.

METHODS

The postoperative results of 18 cases (18 eyes) whose posterior capsular of lens ruptured with a impending dropped nucleus during the phacoemulsification were studied retrospectively. Three surgical techniques to prevent lens nucleus' fragments dropping into the vitreous cavity were applied. They are consecutive phacoemulsification with lower flowing rate and lower irrigation, injection of viscoelastic substance with high elasticity and anterior segment vitrectomy with no irrigation. The follow-up was 12-24 months (average, 18.2 months).

RESULTS

Except for a special case, no lens nucleus' fragments dropped into the vitreous cavity. Posterior chamber intraocular lens(IOL) was implanted primarily in all cases (18 eyes). Best corrected visual acuity was above 0.5 in 15 eyes (83.3%). The main complications included corneal edema and cystoid macular edema.

CONCLUSION

With safety, effectiveness and less complications, these three surgical techniques are suitable to deal with different types of impending dropped lens nucleus' fragments during the phacoemulsification. It is advisable to apply these techniques in clinical practice.

[Changes of elastase in gingival crevicular fluid after periodontal treatment of adult periodontitis patients]

OBJECTIVE

To examine the changes of elastase in the supernatant (EA-s) and in the pellet (EA-p) after centrifuge in gingival crevicular fluid (GCF) before and after periodontal treatment.

METHODS

GCF was sampled with filter paper strips by intra-pocket method to determine EA levels. Forty-three teeth of eight subjects were included. EA-s and EA-p were determined separately using the subtract Meosuc-ala-ala-val-pro-NA.

RESULTS

EA-s per site and per ml, EA-p per site and the ratio of EA-s/EA-p (S/P) decreased significantly after non-surgical periodontal treatment (P < 0.001), while EA-p concentration didn't change (P > 0.05).

CONCLUSIONS

GCF-EA-s and EA-p could act as objective parameters to evaluate the effect of periodontal therapy, especially EA-s and S/P, which may be sensitive diagnostic parameters for determining periodontal disease activity.

[Gingival crevicular fluid enzyme levels at different destruction sites in the same teeth]

OBJECTIVE

To direct selecting proper sampling methods and sites in clinical research.

METHODS

Gingival crevicular fluid (GCF) was sampled separately at the mesial-buccal and distal-buccal sites in the same teeth, which were destroyed differently. Clinical parameters were recorded in the subject sites and its adjacent sites. Aspartate Aminotransferase (AST) and Alkaline Phosphatase (ALP) in the GCF were determined. Difference of the enzyme levels between the two sampling sites, and relations between the enzyme level and all the clinical parameters were assessed.

RESULTS

GCF-AST, ALP per sample at severely diseased sites were much higher than that from healthy and/or mild sites in the same teeth. Significant positive correlation (P < 0.001, r > 0.5) was demonstrated between enzyme levels in the sampling sites and probing depth (PD) and attachment level (AL) of the lingual sites. However, there was mild significant correlation (P < 0.05, r = 0.275) between ALP level in the sampling sites and PD of the proximal-buccal sites of its adjacent teeth. No significant correlation (P > 0.05) was found between AST level in the sampling sites and PD, AL of the adjacent teeth sites, and also between ALP level in the sampling sites and AL of the adjacent teeth sites.

CONCLUSION

Site-specificity of periodontal disease was further demonstrated. GCF components were influenced reciprocally more obviously in the same proximal than by other sites.

Mechanisms of spiroplasma genome variation associated with SpV1-like viral DNA inferred from sequence comparisons

Genomes of Spiroplasma citri strains have rearranged frequently during their evolution, partly due to multiple integrated sequences of spiroplasma viruses. To understand better the role of viral sequences in genome evolution, we examined available nucleotide sequences of viruslike elements in the S. citri chromosome. Comparison of integrated and nonintegrated sequences of spiroplasma virus SpV1-C74 DNA suggested that it is an encapsidated form of the circular transposition intermediate belonging to an insertion sequence (IS3) family member. One SpV1-C74 viral DNA fragment was identified as interrupting the remains of a DNA adenine modification methylase gene. A viral DNA insertion of SpV1-R8A2 B DNA had hallmarks of having suffered an internal deletion by a site-specific recombination system. Homologous recombination likely was responsible for several deletions within viral DNA. A homologous recombination event was inferred between part of a viral DNA insertion and a similar chromosomal sequence. Dispersed sequences from SpV1-like C4 open reading frames (ORFs) were identified as involved in a complex deletion-inversion event. Thus, SpV1-like sequences likely have altered spiroplasma genomes by inserting within active genes, destroying their function, by providing targets for site-specific recombination, by mediating deletions of sequences adjacent to their integration sites, and by providing targets for homologous recombination, leading to inversions.

[Relationship between elastase activity and leukocyte counts in gingival crevicular fluid]

OBJECTIVE

To determine the relationship among the elastase(EA) activity in the supernatant (EA-s), and in the pellet (EA-p) after centrifuge, and polymorphonuclear leukocyte (PMN) counts in gingival crevicular fluid.

METHODS

Gingival crevicular fluid (GCF) was sampled with filter paper strips by intra-pocket method to determine EA levels and then with gingival crevicular washings after 24 hours at the same site for PMN counting. The levels of EA-s and EA-p were determined seperately using the subtract Meosuc-ala-ala-val-pro-NA. PMNs at the same site were counted with light microscope.

RESULTS

The research demonstrated significantly positive correlation among EA-s and EA-p per site and the PMN counts in GCF (P < 0.001).

CONCLUSION

GCF-EA-p per site could reflect the amount of PMNs collected from the pockets, and EA can be the marker of PMN in GCF.

[Clinical study on pelvic venous congestion syndrome after tubal sterilization]

OBJECTIVE

To study the clinical features, diagnosis and therapy of pelvic venous congestion syndrome after tubal sterilization.

METHODS

By using laparoscopy combined with transmyometrial pelvic venophogram and samples after operation, pathomorphology of pelvic congestion venous is observed.

RESULTS

The coincidence rate of laparoscopic diagnosis is 94.6% (53/56), compared with transmyometrial pelvic venophogram. There is no significant difference for light or severe type patients (P > 0.05). The cure rate of the cases in this group is 60.7%, the improvement rate is 16.1%, total effectiveness rate is 76.8%. The effectiveness rate of operational treatment is 90.1%, conservative treatment is 18.2%.

CONCLUSIONS

Laparoscopy is very valuable for the diagnosis of this disease. Laparoscopy combined with transmyometrial pelvic venophogram can be regarded as the major method to diagnosis pelvic venous congestion syndrome. It is recommended that operation for patients with medium and severe symptoms.

[Comparison of sampling methods and their effects on alkaline phosphatase levels in gingival crevicular fluid]

OBJECTIVE

To observe the change of alkaline phosphatase (ALP) after repeat sampling and compare the two sampling methods (orifice method and intra-pocket method).

METHODS

Gingival crevicular fluid (GCF) was sampled repeatedly by the interval of 20 minutes, with orifice and intra-pocket method respectively, and the levels of ALP in GCF were determined.

RESULTS

Mean levels of ALP per site and concentration of ALP are not statistically different between two samples after repeat sampling with-orifice method as well as intra-pocket method (P > 0.05). ALP levels (per site and per microliter) are much higher for intra-pocket method than orifice method (P < 0.001). From the viewpoint of the numbers of recovery sites after repeat sampling, though ALP levels at most sites can't entirely recover to their original levels with both method, intra-pocket method is still a little better than orifice method, and ALP levels per site is better than ALP concentration.

CONCLUSION

The interval of repeat sampling should be prolonged more than 20 minutes. It is better to determine the GCF-ALP with intra-pocket method and also the recommended pattern that express enzyme levels is total activity per site but not concentration.

Analysis of the Bacillus subtilis S10 ribosomal protein gene cluster identifies two promoters that may be responsible for transcription of the entire 15-kilobase S10-spc-alpha cluster

We have sequenced a previously uncharacterized region of the Bacillus subtilis S10 ribosomal protein gene cluster. The new segment includes genes for S10, L3, L4, L23, L2, S19, L22, S3, and part of L16. These B. subtilis genes map in the same order as the genes in the Escherichia coli S10 ribosomal protein operon. Two potential promoter sequences were identified, one approximately 200 bases and the other approximately 140 bases upstream of the S10 gene. The activities of the two promoters were demonstrated by primer extension analysis, in vitro transcription experiments, and in vivo promoter fusion plasmid studies. In agreement with previous reports, our Northern analysis of exponentially growing cells failed to identify terminators or other active promoters within the S10-spc-alpha region. Our observations suggest that the two S10 promoters reported here are responsible for transcribing a 15-kb-long transcript for all of the genes in the B. subtilis S10, spc, and alpha clusters.

[An investigation on peri-implant status in different types of dental implant]

Clinical, biochemical and microbiological methods were used to study the peri-implant status in different types of dental implant. Sixteen normal healthy adults with 12 one-stage implants and 22 two-stage implants were included in this study. Clinical parameters, proportion of subgingival spirochetes, detection rate of spirochetes were found to be significantly higher around one-stage implants than those around two-stage implants. No significant difference in gingival crevicular fluid flow, levels of aspartate aminotransferase and alkaline phosphatase was found between these two types. The bleeding index score in sites which harbored spirochetes was significantly higher than that in sites without spirochetes. The present data suggested that accumulation of plaque and existance of periodontal pathogens maybe related to peri-implant inflammation. This study suggests that plaque control and regular recall should be emphasized in implant maintenance.

Light-dependent systemic infection of solanaceous species by cauliflower mosaic virus can Be conditioned by a viral gene encoding an aphid transmission factor

Gene II of cauliflower mosaic virus (CaMV), which encodes an 18-kDa protein originally identified as an aphid transmission factor (ATF), influences host specificity in a light-dependent manner. A point mutation within the ATF gene that occurs in several CaMV strains was responsible for conditioning light-dependent systemic infections. A point mutant of CaMV strain W260 that carried the single mutation within the ATF gene was able to systemically infect Nicotiana bigelovii at low light intensity (100-180 micromol m-2 sec-1), but not at a higher light intensity level (350-450 micromol m-2 sec-1), while the wild-type W260 virus could systemically infect N. bigelovii under both light conditions. The same point mutation also affected the stability of the amorphous CaMV inclusions and previous studies have shown that it abolishes transmission of CaMV by aphids. The point mutation within the ATF gene that mediated light-dependent infections was complemented by transgenic N. bigelovii plants that express the CaMV gene VI product, a viral protein that has been identified as a translational transactivator. The complementation studies indicated that the ATF gene may influence systemic infections through an interaction with the CaMV gene VI product. The ATF gene of CaMV may contribute to viral infections by regulating expression of downstream genes or by influencing cell-to-cell or long distance movement within the plant.

[The effect of sampling repetition on gingival crevicular fluid and aspartate aminotransferase activity]

The purpose of the present investigation was to evaluate the influence on sampling repetition of aspartate aminotransferase (AST) level with 10-minute intervals. Tests based on the composition of gingival crevicular fluid (GCF) for detection of active periodontitis and GCF require the repetition of sampling. Two 30-second samples of GCF were harvested with 10-minute intervals from 123 sites in 10 healthy subjects and 20 periodontitis patients. AST activity of the first samples in periodontitis subjects were approximately 7.8% greater than that of the second samples. The difference were not significant (P > 0.05). But in healthy subjects the difference were significant (P < 0.05). AST activity correlation positively with bleeding index (BI) and probing pocket depth (PD).

[Effects of gossypol acetic acid on human ejaculated sperm Ca2+ influx and rat vas deferens contraction action]

It has been reported that gossypol acetic acid (GAA) inhibits sperm motility and calcium plays an important role in regulating the function of the sperm flagella. In order to explore the mechanism by which GAA inhibits sperm motility, the effects of GAA on human ejaculated sperm Ca2+ influx and isolated rat vas deferens contraction action were studied. The results showed that GAA inhibited sperm Ca2+ influx in a dose-dependent manner, and breaked the dynamic equilibrium of sperm internal and external Ca2+ gradient concentrations. It may be one of important mechanism by which GAA inhibits sperm motility. But GAA exerts no effect on the high K+ induced contraction of smooth muscle of isolated rat vas deferens. It is likely that GAA has selective action on the sperm membrane of the rats.

Complementarity determining region residues aspartic acid at H55, serine at H95 and tyrosines at H97 and L96 play important roles in the B72.3 antibody-TAG72 antigen interaction

Structural analysis derived from the crystallographic study of the chimeric B72.3 antibody illustrated some major atomic interactions between complementarity determining region (CDR) residues. For example, hydrogen bonds are formed between H35/H95, L50/H97, H53/H55 and H96/L96 respectively. These CDR residues may play important roles in the B72.3-TAG72 (antibody-antigen) interaction either by direct interaction with the TAG72 antigen or by maintaining a CDR loop conformation through atomic interactions between CDR residues. In order to confirm these assumptions, we altered these CDR residues by site-directed mutagenesis and determined binding affinities of these mutant chimeric antibodies for the TAG72 antigen in a solid-phase radioimmunoassay. We found that H55, H95, H97 and L96 are important CDR residues for the B72.3-TAG72 interaction. Single amino acid substitutions of aspartic acid and serine by alanine at H55 of CDR2 and at H95 of CDR3 respectively and of tyrosine by phenylalanine at H97 and L96 of CDR3, significantly reduced the binding affinity for the TAG72 antigen by 20-, 8-, 16- and 45-fold respectively. Therefore, this study reveals some of the requirements for maintaining the integrity of the B72.3 antibody combining sites.

Framework residues 71 and 93 of the chimeric B72.3 antibody are major determinants of the conformation of heavy-chain hypervariable loops

Structural analysis derived from the crystallographic study of the chimeric B72.3 antibody illustrated that some heavy-chain framework residues having atomic interactions with heavy-chain CDR residues may directly affect the conformation of CDR loops. For example, an alanine residue at H71 provides room for packing CDR2/CDR1 and lysine residues at H73 and H93 contribute a salt-bridge to aspartic acid at H55 in CDR2 and a hydrogen bond to the carbonyl group at H96 in CDR3, respectively. We have analysed the contribution of these framework residues to the TAG72-binding affinity. We altered these framework residues by site-directed mutagenesis, and determined the affinity of these mutant chimeric antibodies for the TAG72 antigen by solid phase radioimmunoassay. We found that a single amino acid substitution of alanine by phenylalanine at H71 or lysine by isoleucine at H93, significantly reduced the binding affinity for the TAG72 antigen by 12 and 20-fold, respectively, whereas the substitution of lysine by alanine at H73 reduced the binding affinity only two-fold. Our results indicate that heavy-chain framework residues alanine at H71 and lysine at H93 of the chimeric B72.3 antibody are the major determinants of the conformation of heavy-chain CDR2/CDR1 and CDR3 loops, whereas the salt-bridge between lysine at H73 and aspartic acid at H55 is less important. The hydrogen bond between two framework residues, glutamine at H5 and serine at H25 does not affect any CDR conformation. Our results will thus be of importance especially when the humanized B72.3 antibody is constructed by grafting the CDR loops to a human framework. The important framework region interactions must be maintained in the final humanized antibody.

Expression of a plant viral polycistronic mRNA in yeast, Saccharomyces cerevisiae, mediated by a plant virus translational transactivator

We demonstrate that the cauliflower mosaic virus (CaMV) gene VI product can transactivate the expression of a reporter gene in bakers' yeast, Saccharomyces cerevisiae. The gene VI coding sequence was placed under the control of the galactose-inducible promoter GAL1, which is presented in the yeast shuttle vector pYES2, to create plasmid JS169. We also created a chloramphenicol acetyltransferase (CAT) reporter plasmid, JS161, by inserting the CAT reporter gene in-frame into CaMV gene II and subsequently cloning the entire CaMV genome into the yeast vector pRS314. When JS161 was transformed into yeast and subsequently assayed for CAT activity, only a very low level of CAT activity was detected in cellular extracts. To investigate whether the CaMV gene VI product would mediate an increase in CAT activity, we cotransformed yeast with JS169 and JS161. Upon induction with galactose, we found that CAT activity in yeast transformed with JS161 and JS169 was about 19 times higher than the level in the transformants that contained only JS161. CAT activity was dependent on the presence of the gene VI protein, because essentially no CAT activity was detected in yeast cells grown in the presence of glucose, which represses expression from the GAL1 promoter. RNase protection assays showed that the gene VI product had no effect on transcription from the 35S RNA promoter, demonstrating that regulation was occurring at the translation level. This yeast system will prove useful for understanding how the gene VI product of CaMV mediates the translation of genes present on a eukaryotic polycistronic mRNA.

Role of NusA in L4-mediated attenuation control of the S10 r-protein operon of Escherichia coli

The transcription of the 11 gene S10 operon of Escherichia coli is autogenously regulated by one of the operon's products, ribosomal protein L4. This protein stimulates termination of transcription in vivo at a specific site within the S10 leader. The in vivo effect can be reproduced in a purified transcription system but requires an additional factor, NusA. Our earlier in vitro studies showed that NusA is required for RNA polymerase pausing at the termination site; such paused complexes are further stabilized by L4, which presumably accounts for L4's stimulation of termination in vivo. Here we show that NusA is not absolutely required for RNA polymerase to recognize the attenuation site: at low (5 microM) UTP concentration, RNA polymerase pauses at the site, although the paused transcription complex formed in the absence of NusA can be further stabilized by subsequent addition of the protein. Furthermore, RNA polymerase pausing at the attenuation site is not sufficient for the L4 effect, since L4 cannot stabilize a transcription complex paused at the attenuation site in the absence of NusA. We have been able to isolate paused complexes formed without NusA and/or L4; such complexes are active upon re-addition of NTPs, and respond as expected to the addition of L4 or NusA. Our experiments are consistent with the notion that L4 is a stable component of a paused transcription complex.

RNA determinants required for L4-mediated attenuation control of the S10 r-protein operon of Escherichia coli

We have probed regions of the S10 leader RNA to determine their role in L4-mediated, NusA-dependent attenuation control of the S10 ribosomal protein operon. Using genetic and "antisense" oligonucleotide competition approaches, we were able to distinguish between the determinants necessary for intrinsic (NusA-independent) pausing by RNA polymerase at the S10 attenuation site, for NusA-dependent enhancement of pausing, and for L4 stabilization of the paused ternary complex. The upper stem-loop structure in the attenuator hairpin is the major determinant for the NusA-dependent pause, while the sequence at the site of pausing is important for RNA polymerase to pause in the absence of NusA. The determinants for L4 stabilization of the paused complex include the hairpin immediately upstream of the attenuator hairpin as well as the ascending side of the attenuator structure. In conclusion, our results suggest that there are three distinct pausing activities by RNA polymerase during its transcription of the S10 leader, with three corresponding signals in the S10 leader.

A heavy-chain grafted antibody that recognizes the tumor-associated TAG72 antigen

Murine anti-TAG72 antibodies react with more than 85% of human colorectal, gastric and ovarian carcinomas. However, the therapeutic utility of murine antibodies in human is severely restricted by their immunogenicity. The construction of humanized antibodies can potentially circumvent this problem. The latter antibodies can be generated by grafting CDRs from a murine antibody onto human immunoglobulin FRs followed by combining the resultant product with human immunoglobulin constant regions. In this study, we constructed a heavy-chain humanized anti-TAG72 antibody that we designated hmM4. This was achieved by the transplantation of CDRs from the murine VH of the ccM4 antibody into FRs of the human myeloma protein NEWM. The humanized antibody hmM4 retained its binding reactivity for the TAG72 antigen as measured by ELISA and Western blotting analysis respectively. However, it showed considerably less immunoreactivity for the TAG72 antigen than the original chimeric antibody ccM4. These results indicate that the murine anti-TAG72 specificity can be grafted to human immunoglobulin, and that the choice of the human immunoglobulin framework for the grafted antibody may be critical in maintenance of the immunoreactivity.

Infantile spasms. A retrospective study of 105 cases

This paper is a summary of our observations on 105 cases of infantile spasms. The age of onset was around six months after birth, but the patients came for treatment mainly about one year after onset. Fever of unknown cause, asphyxia, birth injury, infection of the central nervous system, tuberous sclerosis, phenylketonuria and recent immunization etc. were complained. Clinically, it is characterized by head nodding, mental retardation, myoclonic jerks and various neurologic deficits. EEG findings showed classical or modified arrythmia or other epileptiform patterns. About one third of 22 cases examined had abnormal brain stem auditory evoked potentials. Among 42 patients who underwent CT scanning before ACTH treatment, 18 were normal and 7 abnormal; during ACTH treatment 3 normal and 4 abnormal; after completion of treatment, 4 normal and 6 abnormal, suggesting no further atrophy of the brain. Examination of trace elements of the hair by particle-induced X-ray emission (PIXE) method in 23 patients revealed a significant difference in lead, calcium and zinc contents between patients and 101 controls, but no statistical difference in iron and copper contents between the two groups. Sodium valproate, prednisone and ACTH appear to be effective in the treatment of infantile spasms. Eight patients fully recovered, and they can go to school without difficulty. Many patients derived various degrees of improvement to the satisfaction of their parents. Two patients were still amented and often attacked by myoclonus. The effects, side effects of these drugs, and the possible pathogenesis were discussed.

Effect of packed cell volume on diastolic coronary artery pressure-flow relations in the dog

To elucidate the role of the haemorheological properties of the perfusate in the coronary circulation, the diastolic pressure-flow relation was studied in nine open chest heart blocked dogs with minimal vasomotor tone when blood with various packed cell volumes (12-67%) was used as perfusate. An electrical analogue model with proximal resistance R1, capacitance C, distal resistance R2, and the zero flow pressure intercept Pint was derived from the observation of the pressure-flow relation to support the data analysis. The diastolic pressure decay was then determined after the perfusion line had been clamped to calculate stop flow coronary artery pressure (Psf). The stop flow coronary artery pressure decreased in relation to packed cell volume (r = 0.45, p less than 0.01), and the value for the lowest packed cell volume (10-29%) was slightly higher than the great cardiac vein pressure (about 3 mmHg). The zero flow pressure intercept of the steady state pressure-flow relation showed a close correlation with the stop flow coronary artery pressure (r = 0.87, p less than 0.001). The value of R1 + R2, which reflects the inverse of the steady state pressure-flow slope, decreased simultaneously with the packed cell volume (r = 0.62, p less than 0.001). The resistance ratio R2/(R1 + R2) by our model prediction decreased in relation to packed cell volume (r = 0.5, p less than 0.001). The values of stop flow coronary artery pressure, zero flow pressure intercept, and R1 + R2 for the highest packed cell volume (50-69%) were 17.8(1.1) mmHg, 25.1(1.3) mmHg, and 0.48(0.05) mmHg.ml-1.min.100 g-1 respectively, whereas those for the lowest packed cell volume (10-29%) were 13.4(0.8) mmHg, 19.7(1.0) mmHg, and 0.24(0.02) mmHg.ml-1.min.100 g-1. The pressure difference between the stop flow coronary artery pressure and the zero flow pressure intercept may be due to the non-linearity in the pressure-flow relation at a low perfusion pressure. The left ventricular end diastolic pressure and great cardiac vein pressure did not change in relation to the packed cell volume of the coronary perfusate. Thus it is concluded that packed cell volume is one factor determining the high zero flow pressure.