Cloning of DPK, a novel dendritic cell-derived protein kinase activating the ERK1/ERK2 and JNK/SAPK pathways

Mitogen-activated protein kinase (MAPK) cascades are the major signaling systems transducing extracellular signals into intracellular responses, which mainly include the extracellular signal-regulated kinase (ERK) pathway, the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) pathway, and the p38 pathway. From dendritic cell cDNA library, we isolated a full-length cDNA encoding a potentially novel 898-residue kinase, which was designated DPK. The protein contained a potential kinase domain at the N-terminal exhibiting homology with MEKK1-, MEKK2-, MEKK3-, MEKK4-, MEKK5-, Tpl-2-, and p21-activated kinases (PAKs), but no GTPase-binding domain which is characteristic of PAKs. Northern blotting analysis showed that DPK was ubiquitously expressed in normal tissues, with abundant expression in kidney, skeletal muscle, heart, and liver. When overexpressed in transfected NIH3T3 cells, it could activate both the ERK1/ERK2 pathway and the SAPK pathway in a dose-dependent manner, but not affect the p38 pathway. These findings suggested that DPK might be a novel candidate MAPKKK.

Analysis of acyclovir by high performance capillary electrophoresis with on-column amperometric detection

The separation of acyclovir (ACV) by high performance capillary electrophoresis (HPCE) with on-column amperometric detection using alpha-amino-5-mercapto-3,4-dithiazole (AMD) as internal standard is described. The calibration line was linear in the range of 0.5-20 mg/L of ACV. The detection limit was 0.15 mg/L of ACV. Its recovery ranged from 98 to 101% with relative standard deviations (RSDs) from 1.9 to 3.2% (n = 5). This method was successfully used for determining ACV in some pharmaceuticals and human urine. Comparable results with HPCE with ultraviolet (UV) detection and amperometric detection were obtained.

Peptide deformylase in Staphylococcus aureus: resistance to inhibition is mediated by mutations in the formyltransferase gene

Peptide deformylase, a bacterial enzyme, represents a novel target for antibiotic discovery. Two deformylase homologs, defA and defB, were identified in Staphylococcus aureus. The defA homolog, located upstream of the transformylase gene, was identified by genomic analysis and was cloned from chromosomal DNA by PCR. A distinct homolog, defB, was cloned from an S. aureus genomic library by complementation of the arabinose-dependent phenotype of a P(BAD)-def Escherichia coli strain grown under arabinose-limiting conditions. Overexpression in E. coli of defB, but not defA, correlated to increased deformylase activity and decreased susceptibility to actinonin, a deformylase-specific inhibitor. The defB gene could not be disrupted in wild-type S. aureus, suggesting that this gene, which encodes a functional deformylase, is essential. In contrast, the defA gene could be inactivated; the function of this gene is unknown. Actinonin-resistant mutants grew slowly in vitro and did not show cross-resistance to other classes of antibiotics. When compared to the parent, an actinonin-resistant strain produced an attenuated infection in a murine abscess model, indicating that this strain also has a growth disadvantage in vivo. Sequence analysis of the actinonin-resistant mutants revealed that each harbors a loss-of-function mutation in the fmt gene. Susceptibility to actinonin was restored when the wild-type fmt gene was introduced into these mutant strains. An S. aureus Deltafmt strain was also resistant to actinonin, suggesting that a functional deformylase activity is not required in a strain that lacks formyltransferase activity. Accordingly, the defB gene could be disrupted in an fmt mutant.

Relationship between pericardial pressure and lymphatic pericardial fluid transport in sheep

We investigated the relationship between pericardial pressure and the volumetric lymphatic clearance rate of pericardial fluid in sheep. A single catheter perfusion system was established to deliver tracer to the pericardial cavity and control pericardial pressure. In addition, catheters were placed into the thoracic duct and into the jugular vein at the base of the neck. (125)I-human serum albumin (HSA) was administered into the pericardial perfusate to serve as the lymph flow marker and its concentration monitored in the effluent from the outflow end of the perfusion system. (131)I-HSA was injected intravenously to permit calculation of plasma tracer loss and tracer recirculation into lymphatics. From mass balance equations, estimates of total pericardial clearance into lymphatics increased significantly as pericardial pressures were elevated in 2. 5 cm H(2)O increments from 2.5 to 12.5 cm H(2)O (P = 0.018). Pericardial lymph transport ranged from 0.89 +/- 0.10 to 3.09 +/- 0. 66 ml/h at 2.5 and 12.5 cm H(2)O pericardial pressure, respectively. The majority of transport occurred through mediastinal vessels with a small proportion (10.3 to 23.9%) being cleared into lymphatics leading to the thoracic duct. We conclude that lymphatic pericardial fluid transport increases approximately 3.5-fold over a pericardial pressure range that encompasses the transition between the shallow and steep portions of the pericardial pressure-volume relationship.

Neural electrophysiological studies on the external anal sphincter in children with anorectal malformation

BACKGROUND/PURPOSE

Abnormality of innervation of external anal sphincter is one of the most important factors affecting postoperative anorectal function. The abnormalities of lumbosacral nerves have been reported in many radiological and histopathologic studies. There are few reports on the neurophysiological changes in children with anoractal malformation. The aim of this study was to examine the functional changes of nerves to the external anal sphincter in anorectal malformation.

METHODS

Forty-five patients with anorectal malformation underwent studies of latencies of pudendo-anal reflex, spinoanal response, and evoked potential of cauda equine simultaneously. The conduction time of afferent nerve, efferent nerve, and sacral spinal center of pudendo-anal reflex arc were analyzed quantitatively.

RESULTS

The latencies of pudendo-anal reflex, spino-anal response, and conduction time of sacral spinal center significantly are prolonged in patients with anorectal malformation (P< .05). There was significant difference between rectourethral fistula group and vestibular fistula group as well as low-type deformity group. The patients with lumbosacral anomalies such as lumbosacral spinal bifida or absence of S4 or S5 had prolonged latencies, especially the pudendo-anal reflex latency. There was significant negative correlation between the latencies and clinical scores. Although pudendoanal reflex latency was longer in patients who had posterior sagittal anorectoplasty than those who had abdominoperineal pull-through procedure, the difference was not significant.

CONCLUSIONS

The abnormality of nerves to external anal sphincters is one of the important causes for clinical outcome. The neural lesions vary in each type of anal and lumbosacral deformity.

Patterns of endoscopic follow-up after surgery for nonmetastatic colorectal cancer

BACKGROUND

Endoscopic examinations of the colon are often recommended for surveillance following colorectal cancer resection. The actual use and outcome of this testing are not known.

METHODS

Five thousand seven hundred sixteen patients 65 years of age or older with local or regional stage colorectal cancer diagnosed in 1991 were identified through the Surveillance Epidemiology and End Results registry. All inpatient and outpatient Medicare claims from 6 months after diagnosis through the end of 1994 were examined to determine use of endoscopic procedures.

RESULTS

One or more colonoscopies were performed in 51%, with an average of 2.9 procedures performed among those tested; sigmoidoscopy was performed in 17%. The rate of colonoscopy was highest during the initial 18 months. Polypectomy was performed in 21% of all patients, and subsequent primary colorectal tumors were diagnosed in 1.3%. Factors associated with colonoscopy and sigmoidoscopy use included younger age, survival through follow-up, and geographic region; sigmoidoscopy was also more common in relation to rectal cancers.

CONCLUSIONS

There is variability in the use of endoscopic procedures following potentially curative resection for colorectal cancer, with patient-related factors and local practice patterns accounting for the variation. Further studies are needed to elicit the reasons for lack of follow-up and adherence to practice guidelines.

[A study on the determination method of biological function of BRF]

This study was aimed to establish a method for determining the biological function of biological wave regulating factor (BRF). Proteus mirabilis was used to set up the experimental model. The biological function of the component obtained from wave growth media beneath the bacterial colony rings resulting from bacterial proliferation was determined in biological wave test by analytically microbiological method. The results indicated that BRF could enhance biological wave and shorten its period. The method is of some value in studying the regulative mechanism of biological wave.

Coexpression of cyt1Aa of Bacillus thuringiensis subsp. israelensis with Bacillus sphaericus binary toxin gene in acrystalliferous strain of B. thuringiensis

The cyt1Aa gene of Bacillus thuringiensis subsp. israelensis and binary toxin gene of Bacillus sphaericus C3-41 were introduced into an acrystalliferous strain of B. thuringiensis independently and in combination by using shuttle vector pBU4. SDS-PAGE and Western blot analysis proved that cyt1Aa and binary toxin genes coexpressed during the sporulation of the recombinant. Transformant strain expressing the Cyt1Aa and binary toxin proteins in combination was more toxic to susceptible and resistant Culex pipiens quinquefasciatus than the transformants expressing Cyt1Aa protein or binary toxin proteins independently. It was suggested that large amount of production of Cyt1Aa protein and binary toxin proteins possibly interacted synergistically, thereby increasing its mosquitocidal toxicity significantly.

Agreement of Medicare claims and tumor registry data for assessment of cancer-related treatment

BACKGROUND

Although health claims data are increasingly used in evaluating variations in patterns of cancer care and outcomes, little is known about the comparability of these data with tumor registry information.

OBJECTIVES

To evaluate the agreement between Medicare claims and tumor registry data in measuring patterns of diagnostic and therapeutic procedures for older cancer patients.

RESEARCH DESIGN

Analysis of a database linking Surveillance, Epidemiology and End Results (SEER) registry data and Medicare claims in patients aged > or =65 years with cancer.

SUBJECTS

361,255 Medicare patients with invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancer diagnosed between 1984 and 1993.

MEASURES

Concordance of SEER files with corresponding Medicare claims.

RESULTS

Medicare claims generally identified patients who underwent resection and radical surgery according to SEER (ie, concordance > or =85%-90%) but less likely biopsy or local excision (ie, concordance < or =50%). In some instances, claims also categorized patients as having more invasive surgery than was listed in SEER and also provided incremental information about the use of surgical treatment after 4 months. SEER files and, to a lesser degree, Medicare claims identified radiation therapy not included in the other data source, and Medicare files also captured a significant number of patients with codes for chemotherapy.

CONCLUSIONS

Medicare files may be appropriate for studies of patterns of use of surgical treatment, but not for diagnostic procedures. The potential benefit of Medicare claims in identifying delayed surgical intervention and chemotherapy deserves further study.

[Exploration of the mechanism of skin expansion]

OBJECTIVE

In order to explore the mechanism of skin expansion technique (SET).

METHODS

Domestic dogs were used in this experiment. The epidermal mitotic activity, capillary blood flow change of the expanded flap were observed with microspectrophotometer and radioactive microsphere technique.

RESULTS

1. The epidermis of expanded skin was significantly thicker than that of other groups (P < 0.05). 2. The epidermal mitotic activity was elevated significantly(P < 0.01). 3. The capillary blood flow of expanded flaps increased significantly (P < 0.01).

CONCLUSIONS

1. The surplus skin produced by SET is the result of replication, not compensation. 2. SET increases skin blood flow, therefore enlarges the survival area of an expanded flap.

Quality of life for children with fecal incontinence after surgically corrected anorectal malformation

PURPOSE

The aim of this study was to investigate influences of fecal incontinence on children's quality of life after surgically corrected anorectal malformation.

METHODS

Seventy-one children with anorectal malformation underwent follow-up for 8 to 16 years postoperatively. They were divided into good, fair, and poor groups by assessment of anal function. The quality of life was investigated by self-structured disease impact questionnaires and Achenbach's Child Behavior Check List (CBCL). A quality-of-life scoring criteria was established to assess quality of life of the 71 children with operated anorectal malformation and controls.

RESULTS

Owing to fecal incontinence, 12 (16.9%) children reported that there were problems in peer relationships; school absences happened in 13 (18.3%) children; 17 (23.9%) children had to restrict themselves to certain food. Based on CBCL, 13 (18.3%) children had behavior problems. The behavior problems in children with poor fecal continence (66.7%) were significantly higher than those of children with good fecal continence (8.6%). According to the quality-of-life scoring criteria, the scores of children with operated anorectal malformation (9.4+/-3.7) were significantly lower than those of the controls (11.2+/-0.9). The scores of children with poor fecal continence (4.8+/-1.4) were significantly lower than those of children with good fecal continence (10.9+/-1.2).

CONCLUSIONS

The children with poor fecal continence have poor quality of life caused by fecal dysfunction. Attention should be paid to the rehabilitation of fecal continence after surgery, such as bowel training and biofeedback therapy. The somatic and psychological care and long-term follow-up are necessary to improve the quality of life.

Actinonin, a naturally occurring antibacterial agent, is a potent deformylase inhibitor

Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian cells, thus making it an attractive target for the discovery of novel antibiotics. We have identified actinonin, a naturally occurring antibacterial agent, as a potent PDF inhibitor. The dissociation constant for this compound was 0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from Staphylococcus aureus gave a similar value. Microbiological evaluation revealed that actinonin is a bacteriostatic agent with activity against Gram-positive and fastidious Gram-negative microorganisms. The PDF gene, def, was placed under control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels in the cell by varying the external arabinose concentration. The susceptibility of this strain to actinonin increases with decreased levels of PDF expression, indicating that actinonin inhibits bacterial growth by targeting this enzyme. Actinonin provides an excellent starting point from which to derive a more potent PDF inhibitor that has a broader spectrum of antibacterial activity.

How good is prediction of protein structural class by the component-coupled method?

Proteins of known structures are usually classified into four structural classes: all-alpha, all-beta, alpha+beta, and alpha/beta type of proteins. A number of methods to predicting the structural class of a protein based on its amino acid composition have been developed during the past few years. Recently, a component-coupled method was developed for predicting protein structural class according to amino acid composition. This method is based on the least Mahalanobis distance principle, and yields much better predicted results in comparison with the previous methods. However, the success rates reported for structural class prediction by different investigators are contradictory. The highest reported accuracies by this method are near 100%, but the lowest one is only about 60%. The goal of this study is to resolve this paradox and to determine the possible upper limit of prediction rate for structural classes. In this paper, based on the normality assumption and the Bayes decision rule for minimum error, a new method is proposed for predicting the structural class of a protein according to its amino acid composition. The detailed theoretical analysis indicates that if the four protein folding classes are governed by the normal distributions, the present method will yield the optimum predictive result in a statistical sense. A non-redundant data set of 1,189 protein domains is used to evaluate the performance of the new method. Our results demonstrate that 60% correctness is the upper limit for a 4-type class prediction from amino acid composition alone for an unknown query protein. The apparent relatively high accuracy level (more than 90%) attained in the previous studies was due to the preselection of test sets, which may not be adequately representative of all unrelated proteins.

The N-terminal domain of p73 interacts with the CH1 domain of p300/CREB binding protein and mediates transcriptional activation and apoptosis

The newly identified p53 homolog p73 mimics the transcriptional function of p53. We have investigated the regulation of p73's transcriptional activity by p300/CREB binding protein (CBP). p73-p300 complexes were identified in HeLa cell extracts by cofractionation and coimmunoprecipitation assays. The p73-p300 interaction was confirmed in vitro by glutathione S-transferase-protein association assays and in vivo by coimmunoprecipitating the overexpressed p300 and p73 in human p53-free small-cell lung carcinoma H1299 or osteosarcoma Saos-2 cells. The N terminus but not the N-terminal truncation of p73 bound to the CH1 domain (amino acids [aa] 350 to 450) of p300/CBP. Accordingly, this p73 N-terminal deletion was unable to activate transcription or to induce apoptosis. Overexpression of either p300 or CBP stimulated transcription mediated by p73 but not its N-terminally deleted mutant in vivo. The N-terminal fragment from aa 19 to 597, but not the truncated fragment from aa 242 to 1700 of p300, reduced p73-mediated transcription markedly. p73-dependent transcription or apoptosis was partially impaired in either p300- or CBP-deficient human breast carcinoma MCF-7 or H1299 cells, suggesting that both coactivators mediate transcription by p73 in cells. These results demonstrate that the N terminus of p73 directly interacts with the N-terminal CH1 domain of p300/CBP to activate transcription.

The association between hospital type and mortality and length of stay: a study of 16.9 million hospitalized Medicare beneficiaries

OBJECTIVES

To examine the association between hospital type and mortality and length of stay using hospitalized Medicare beneficiaries for a 10-year period.

METHODS

The retrospective cohort study included 16.9 million hospitalized Medicare beneficiaries > or = 65 years of age admitted for 10 common medical conditions and 10 common surgical procedures from 1984 to 1993. A total of 5,127 acute-care hospitals in the United States were grouped into 6 mutually exclusive hospital types based on teaching status and financial structure (for-profit [FP], not-for-profit [NFP], osteopathic [OSTEO], public [PUB], teaching not-for-profit [TNFP], and teaching public [TPUB]) as reported in the 1988 American Hospital Association database. Logistic and linear regression methods were used to examine risk-adjusted 30-day and 6-month mortality and length of stay.

RESULTS

During the 10-year study period, 10.6 million patients were admitted with 1 of the 10 selected medical conditions, and 6.3 million patients were hospitalized for 1 of the 10 selected surgical procedures. Patients at TNFP hospitals had significantly lower risk-adjusted 30-day mortality rates than patients at other hospital types when all diagnoses or procedures were combined (combined diagnoses: RR(TNFP) = 1.00 [reference], RR(TPUB) = 1.40, RR(OSTEO) = 1.14, RR(PUB) = 1.07, RR(FP) = 1.03, RR(NFP) = 1.02; combined procedures: RR(TNFP) = 1.00 [reference], RR(OSTEO) = 1.36, RR(TPUB) = 1.30, RR(PUB) = 1.16, RR(FP) = 1.13, RR(NFP) = 1.08). The results were mostly consistent when diagnoses and procedures were examined separately. After adjustment for patient characteristics, patients at other hospital types had 10% to 20% shorter lengths of stay (LOS) than patients at TNFP hospitals for most diagnoses and procedures studied.

CONCLUSION

As measured by the risk-adjusted 30-day mortality, TNFP hospitals had an overall better performance than other hospital types. However, patients at TNFP hospitals had relatively longer LOS than patients at other hospital types, perhaps reflecting the medical education and research activities found at teaching institutions. Future research should examine the empirical evidence to help elucidate the adequate LOS for a given condition or procedure while maintaining the quality of care.

[Neural electrophysiological observations on the external anal sphincter in patients with anorectal malformation]

OBJECTIVE

To explore the functional damage of the nerves controlling external anal sphincter in patients with congenital anorectal malformation and to design a new method for measuring the conductive time of sacral spinal center in the pudendo-anal reflex arc.

METHODS

45 patients with anorectal malformation and 20 normal subjects were subjected to detect the latency for pudendo-anal reflex, spinal-anal response and evoked potential of caude equine simultaneously. The conduction time of afferent motor nerve, efferent sense nerve and sacral spinal center in the pudendo-anal reflex arc were quantitatively analyzed.

RESULTS

The normal latency for pudendo-anal reflex was 23.3 +/- 6.9 ms, for spinal-anal response was 4.6 +/- 1.9 ms, and for evoked potential of caude equine was 3.8 +/- 0.9 ms. The conduction time of sacral spinal center was 14.8 +/- 6.6 ms. In patients with anorectal malformation, the latencies were prolonged obviously, especially the conduction time of sacral spinal center. There was a significant negative correlation between the latency and clinical scores. The correlation coefficient for pudendo-anal reflex was -0.68, for spinal-anal response was -0.64, and for conduction time of sacral spinal center was -0.60.

CONCLUSIONS

The abnormality of nerves serving anal sphincters was one of the important causes for postoperative fecal incontinence. The neural lesions are specially serious in the sacral spinal center.

On-line estimation of the maximum specific growth rate of nitrifiers in activated sludge systems

The on-line estimation of the maximum specific growth rate of autotrophic biomass is addressed in this article. A general nitrification process model, which is valid for any realistic flow pattern, is used to develop the estimation algorithm. Depending on the measurements available, two estimation equations are derived. While both require measuring the nitrification activity of the activated sludge, one requires the additional measurement of the nitrifiable nitrogen concentrations at the two ends of the bioreactor, and the other requires the nitrate nitrogen concentrations at the same locations. The algorithm also requires some stoichiometric and kinetic parameters. However, sensitivity analysis shows that the estimate is insensitive to the parameters other than the autotrophic decay rate. Compared to the existing algorithms, the algorithm developed in this article does not rely on the assumption of ideal flow pattern in the plant and does not require an error-prone estimate of the autotrophic biomass concentration. Experimental and simulation studies show that the algorithm performs well and is robust to influent variations and accidental sludge losses.

Colorectal carcinoma screening attitudes and practices among primary care physicians in counties at extremes of either high or low cancer case-fatality

BACKGROUND

To the authors' knowledge, physician attitudes and reported practices regarding colorectal carcinoma screening have not been studied in areas of highest risk for cancer death.

METHODS

Medicare claims were used to calculate colorectal carcinoma 2-year case-fatality rates for counties with >100 incident cases of colorectal carcinoma between 1991-1993. All 2682 practicing primary care physicians in 20 counties with the lowest case-fatality rates (mean of 29.9%) and 19 counties with the highest case-fatality rates (mean of 47.8%) were surveyed regarding their screening procedures and attitudes.

RESULTS

Among the 972 respondents (36.1%), the reported use of fecal occult blood testing (FOBT) and flexible sigmoidoscopy was similar in the low and high case-fatality counties. However, physicians who practiced in the high case-fatality counties were less likely to be trained in and to perform sigmoidoscopy themselves (37.0% vs. 45.6%; P<0.01). Moreover, practitioners in the high case-fatality counties were more likely than the other physicians to consider or plan enhanced FOBT and sigmoidoscopic screening in the near future. FOBT and sigmoidoscopy screening rates at the county level were associated negatively with cancer incidence rates, case-fatality rates, and metastatic disease rates, suggesting a potentially protective effect.

CONCLUSIONS

Geographically targeted interventions are a potentially cost-effective strategy for focusing additional screening services on the highest risk populations. The primary care clinicians in these high risk areas are logical partners for these interventions by virtue of their high degree of readiness to change their current screening practices.

[Combined use of rhBMP2/BCB and free periosteum in repairing segmental defects in radii of rabbits]

OBJECTIVE

To study the efficacy of combined use of rhBMP2/BCBand free periosteal graft in repairing segmental bony defects.

METHODS

A new grafting material (rhBMP2/BCB) was made by combining recombinant human BMP2 (rhBMP2) and an antigen-free bovine cancellous bone (BCB) as a carrier. rhBMP2/BCB was used alone in conjunction with free periosteal graft to repair a 1.5 cm defect in the radius of the rabbit. The defect-repairing capability for each of the treatment modalities was assessed radiographically, biomechanically, and by densitometry and histological studies.

RESULTS

rhBMP2/BCB used alone was capable of healing the defect in large by 16 weeks, with a similar repair process and mechanism seen with RBX. Combined use of rhBMP2/BCB and free periosteal graft was superior in terms of increased amount and quality of the new bone formed at the early stage of the repair process (within 12 weeks) to rhBMP2/BCB used in isolation, with the defect basically healed by 12 weeks.

CONCLUSIONS

Both methods are effective in repairing segmental bony defects, with rhBMP2/BCB used in conjunction with free periosteal graft being most preferred, considering the satisfactory osteogenesis, osteoconduction and osteoinduction.

[Location of the binary toxin gene of Bacillus sphaeriucs and some biological characteristics of its asprogenous mutants]

Location of the binary toxin gene of Bs C3-41 and some biological characteristics of its asporogenous mutants which obtained by DES treatment were studied in this paper. Mutant C4, L5 with blocked at the stage II of sporulation course were not possessed of any crystalline inclusion, but the binary toxin proteins were detected in their cells by SDS-PAGE analysis. Another mutant G5 which blocked at the stage III of sporulation course formed parasporal crystal in the cells, and its toxicity to larvae of Culex quinquefasciatus was about 50 times higher than those of mutant C4 and L5. The result of curing plasmid and Southern blot analysis confirm the binary toxin gene of Bs C3-41, Bs 1691 and Bs-10 locate on the chromosome.

Determination of dissociation constants of amino acids by capillary zone electrophoresis

A method is proposed for the determination of dissociation constants of amino acids by capillary zone electrophoresis. According to the dissociation equilibrium of amino acids and the basic theory of electrophoresis, the nonlinear relationship between the pH value of the buffer and the effective electrophoretic mobilities of the analyte was obtained. The dissociation constants can be calculated from the pH values and the corresponding effective electrophoretic mobilities using the program written in C++. The dissociation constants, pKa1 and pKa2, of 11 kinds of amino acids were determined successfully by the proposed method. The determined dissociation constants were compared with values in the literature; the differences between them are in the range of -0.03 to 0.06. No significant differences were observed between the determined dissociation constants and the corresponding literature values.

Enantiometric separation of amino acids by copper (II)-L-arginine ligand exchange capillary zone electrophoresis

A novel method for the separation of amino acid enantiomers by ligand exchange capillary zone electrophoresis (CZE) using a chiral Cu(II)-L-arginine ligand was developed in this paper. The effects of the buffer concentration, pH, the molar ratio of L-arginine to Cu(II), and the total concentrations of Cu(II) and L-arginine on the migration times and resolutions of chiral amino acids were investigated. The optimum experimental conditions were 40 mmol/L of NH4OAc, pH 7.0, the 2:1 concentration ratio of L-arginine to Cu(II), 1 mmol/L CuSO4 x 5H2O and 2 mmol/L L-arginine. Using the proposed method, six different dansyl-amino acids were separated successfully with the resolution ranging from 1.1 to 2.3 in less than 15 min.

The utility of Medicare claims data for measuring cancer stage

BACKGROUND

The validity of using claims data for measuring tumor stage, one of the most important determinants of choice of therapy and long-term survival, is unknown.

OBJECTIVES

To determine the relative accuracy of both inpatient and hospital Outpatient Medicare claims for measuring the stage of disease of six commonly diagnosed cancers.

RESEARCH DESIGN

Analysis of a database linking Surveillance, Epidemiology, and End Results (SEER) registry data and Medicare claims in patients aged 65 years with cancer.

SUBJECTS

Three hundred twenty thousand, six hundred and thirty seven cases of invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancers diagnosed between 1984 and 1993.

MEASURES

Using SEER files as the "gold standard," concordance with Medicare claims, as well as sensitivity and positive predictive value of coding for each stage was measured.

RESULTS

Although Medicare data correctly categorized local, regional, and distant stage tumors in 97%, 33%, and 65%, respectively, the data substantially overestimated the proportion of localized tumors and underestimated the rate of regional stage disease. The highest concordance was observed for breast and colorectal cancer. However, the sensitivity and positive predictive values were never simultaneously 80% within one stage of a specific cancer. The accuracy of coding for stage in Outpatient files was inferior to inpatient data.

CONCLUSIONS

With few exceptions, Medicare claims have limited utility as a measure of cancer stage. If tumor registry data are not available, investigators should consider the trade offs in sensitivity and predictive value when considering a study that will use claims data.

[Effect of calcium and cristata L extracts on bone mineral density and urinary mineral of rats]

In order to study the effect of cristata L for preventing fluoride toxicity, forty male SD rats were randomly divided into five groups. The control group(NC) was fed with staple feed stuff and tap water, the other four groups were fed with staple feed-stuff and high fluorine water. Except the high fluorine group(F), the other groups were fed with cristata L(FC), high calcium(FCa) and cristata L with high calcium(FCCa) respectively. The results showed that the serum calcium, urinary sodium, calcium, hydroxyproline(HOP) and fluorine contents of high fluorine groups were higher than that of control group; and the urinary calcium content of high calcium group was higher than that of control group. The body weight, BMC and BMD of high fluorine groups was lower than that of control group. The weight of groups FC, FCa and FCCa were significantly higher than that of group F. The BMC and BMD of group FCCa were significantly higher than that of group F. This implies that the food high in fluorine can affect the bone mineral density and urinary minerals of rats, the food supplemented with calcium can reduce the effect of high fluorine, and the food supplemented with both calcium and cristata L is better.

[Study of the 3'noncoding region of Chinese hepatitis C virus genome]

OBJECTIVE

To analyze the 3' noncoding region (3' NCR) of HCV genome from Chinese hepatitis C patients so as to facilitate further study of mechanism of HCV gene replication.

METHODS

Two different strategies were employed to amplify the full-length of the 3' noncoding region of HCV genome from sera of HCV infected patients in Shanghai area: one was to amplify the full-length fragment directly by nested PCR and the other amplify two overlapping fragments. The PCR products were further analyzed by sequencing and nucleotide alignments. A HCV genome 3'NCR based RT-PCR was developed and its specificity and sensitivity for HCV RNA detection in sera was compared with the established 5'NCR based RT-PCR.

RESULTS

Sequence analysis showed that Chinese HCV genomic 3' NCR consists of three parts: the 5' region, poly (U-UC) tract and the 98-base region. Sequence alignments revealed that, while the 98-base regions were completely conserved in different isolates and were identical to the reported sequences, the poly (U-UC) region shared highly diversities. A high degree of concordance(95%) between the 3'NCR and 5'NCR RT-PCR for detection of HCV RNA in sera was found.

CONCLUSION

The high conservation at the 3' NCR(98 bases) of HCV genome among different isolates indicated that this region may be critical for HCV gene replication The 3'NCR based RT-PCR may be a useful addition to available systems to diagnosis HCV infection.