Adenoid basal carcinomas of the cervix: a unique morphological evolution with cell cycle correlates

Adenoid basal carcinoma (ABC) is a rare cervical carcinoma of postmenopausal women composed of small basal-type (basaloid) cells with focal endocervical ("adenoid") differentiation. ABCs are associated with high-grade squamous intraepithelial lesions (HSIL) and contain integrated human papillomavirus type 16 DNA. However, ABCs have a favorable prognosis and do not metastasize. Five (5) ABCs were analyzed histologically for a marker distinguishing basal/ squamous from columnar (adenoid) differentiation (p63) and cell cycle activity (Ki-67), and compared with 20 cervical (CC) carcinomas. In contrast to other CCs, ABCs contained 4 distinct components, including (1) a classic HSIL; (2) a limited invasive component with squamoid maturation, often with a discrete layer of peripheral basal cells; (3) outgrowth of small basal cells from either HSIL or squamoid areas; (4) focal endocervical (adenoid) differentiation. ABCs showed distinct differences in cell cycle activity relative to CCs. Ki-67 positivity was high in associated HSILs but remained high and concentrated in the suprabasal cells of the invasive squamoid component of ABC. Moreover, proliferative index was variable to sharply reduced in areas of basaloid and adenoid differentiation, in contrast to conventional CCs. ABC is a unique neoplasm, not only by its transition through multiple phenotypes during invasion, but also by a proliferative index that is high in more mature neoplastic cells during the infiltrative process and reduced with progressive basal differentiation. The precise mechanism underlying this unique process of tumor evolution is unclear. However, the postmenopausal status of these patients suggests that host factors related to aging may influence tumor evolution and morphology after HPV 16 infection.

Large degree of racemization observed in the amide bond forming reaction on silica gel

A systematic study of racemization from the coupling of DNB-L-Leu and 3-aminopropyl silica gel with several amide coupling reagents was investigated. Significant amounts of racemization were observed from all except one coupling reagent. In comparison, similar reactions completed in homogeneous solution can be accomplished with much lower racemization and in much higher yields.

Nicotine reverses GABAergic inhibition of long-term potentiation induction in the hippocampal CA1 region

Nicotine is known to enhance cognitive function but the mechanism is unknown. The present study examined the modulatory effect of nicotine on the induction of long-term potentiation (LTP), a synaptic model of learning and memory. A weak tetanic stimulation consisting of 20 pulses at 100 Hz induced stable LTP in the hippocampal CA1. The induction of LTP was completely blocked if the tetanus was delivered in the presence of muscimol (2.5 microM), a gamma-aminobutyric acid (GABA) receptor agonist. This inhibition was sensitive to, and reversed by, not only nicotinic acetylcholine receptor (nAChR) agonists (nicotine and epibatidine), but also the alpha7 nAChR-selective antagonist methyllycaconitine (MLA). Furthermore, ACh-puff activation of alpha7 nAChRs on feedforward interneurons induced inhibitory postsynaptic currents in pyramidal cells that were blocked by nicotine or MLA. In addition, nicotine reduced field monosynaptic inhibitory postsynaptic potentials in the presence of MLA. These results suggest not only two pathways of nicotine-induced disinhibition of pyramidal cells, one involving desensitization of alpha7 nAChRs and the other involving non-alpha7 nAChRs, but also two potential mechanisms underlying the modulatory effect of nicotine on LTP induction, both reducing GABAergic inhibition, thereby indirectly increasing the excitability of pyramidal cells.

Molecular characterization of pncA gene mutations in Mycobacterium tuberculosis clinical isolates from China

A sample of 35 pyrazinamide (PZA)-resistant and 30 PZA-susceptible clinical isolates recovered from Beijing and Taiyuan City, China were characterized by SSCP and sequence analysis for mutations in the pncA gene that encodes the Mycobacterium tuberculosis PZase. The purpose of this study was to understand the molecular basis and the characteristics of pncA gene mutations and its relation to PZA resistance in M. tuberculosis strains from China. Several mutations with base changes leading to amino acid substitutions were found in the PZA-resistant isolates. No mutations were seen in the 243 PZA-susceptible isolates. Among the 35 PZA-resistant isolates, 32 isolates (91.4%) had nucleotide substitutions, insertions and deletions that resulted in amino-acid substitution; or frameshifts in some strains. Other previously uncharacterized mutations were found as follows: Asn118->Thr, CG insertion at position 501; CC insertion at nucleotide position 403; a 8 base-pair deletion at start codon; Pro54->Thr; AG insertion at 368; Tyr41->His, Ser88->stop, and A insertion at nucleotide position 301. IS6110 subtyping revealed that each strain was unique; indicative of the epidemiologic independence of the isolates.

p73-deficient mice have neurological, pheromonal and inflammatory defects but lack spontaneous tumours

p73 (ref. 1) has high homology with the tumour suppressor p53 (refs 2-4), as well as with p63, a gene implicated in the maintenance of epithelial stem cells. Despite the localization of the p73 gene to chromosome 1p36.3, a region of frequent aberration in a wide range of human cancers, and the ability of p73 to transactivate p53 target genes, it is unclear whether p73 functions as a tumour suppressor. Here we show that mice functionally deficient for all p73 isoforms exhibit profound defects, including hippocampal dysgenesis, hydrocephalus, chronic infections and inflammation, as well as abnormalities in pheromone sensory pathways. In contrast to p53-deficient mice, however, those lacking p73 show no increased susceptibility to spontaneous tumorigenesis. We report the mechanistic basis of the hippocampal dysgenesis and the loss of pheromone responses, and show that new, potentially dominant-negative, p73 variants are the predominant expression products of this gene in developing and adult tissues. Our data suggest that there is a marked divergence in the physiological functions of the p53 family members, and reveal unique roles for p73 in neurogenesis, sensory pathways and homeostatic control.

Limitations on the quantitative determination of telomerase activity by the electrophoretic and ELISA based TRAP assays

Telomerase is a promising new tumor marker and can be detected using the TRAP (Telomeric Repeat Amplification Protocol) method. To address factors affecting its quantitative determination, we evaluated two commercial TRAP assays, an electrophoretic and an ELISA assay formats, using cultured cells and human tumor samples. We found that both TRAP assays had a limited linearity from 250 to 5000 tumor cells, with a similar intra-assay variation. The quantification of TRAP products was affected by high cell number in sample, the presence of non-tumor cells, and interfering substances in patient specimens. Because both assays have different limitations, determination of telomerase by a combined use of the two may provide more accurate information on the telomerase activity in a specimen. Extracts of specimens should also be tested at several concentrations to insure that the result is not being falsely decreased by an inhibitor. The quantitative results for telomerase activity by the TRAP assays, however, should be interpreted cautiously.

[Partial laryngectomy plus radiotherapy versus partial laryngectomy alone for laryngeal carcinoma]

OBJECTIVE

To investigate the effect of radiotherapy in the combined treatment of laryngeal cancer with partial laryngectomy.

METHODS

One hundred and seventy-one cases of laryngeal cancer were randomly separated into three groups of partial laryngectomy, partial laryngectomy with preoperative radiotherapy (dose 40-50Gy) and partial laryngectomy with postoperative radiotherapy(dose 51-70 Gy). The surgical procedures included cordectomy, vertical partial laryngectomy, horizontal partial laryngectomy and near total laryngectomy.

RESULTS

The overall 5-year survival rate was 82% (123/150). The 5-year survival rates for surgery alone group (56 cases), surgery with preoperative radiotherapy group(65 cases) and surgery with postoperative radiotherapy group(50 cases) were 85.7%, 80.7% and 79.5% respectively. There was no significant difference among the groups(chi 2 = 0.703, P = 0.704). Analysis of survival rates revealed a significant difference among the different stages(chi 2 = 12.248, P = 0.007). All 171 cases except 3 that had near total laryngectomy achieved satisfactory phonation.

CONCLUSION

Neither preoperative radiotherapy nor postoperative radiotherapy can improve the 5-year survival rate of laryngeal cancer with partial laryngectomy. All patients with partial laryngectomy got satisfactory phonation.

Postexposure effectiveness of varicella vaccine

OBJECTIVE

1) To describe the postexposure effectiveness of varicella vaccine in a homeless shelter; and 2) to demonstrate an effective public health intervention and its implications.

DESIGN

A prospective observational study.

SETTING

A women and children's shelter in Philadelphia with 2 cases of varicella before intervention.

OUTCOME MEASURES

Varicella in vaccinated and unvaccinated shelter residents; vaccine effectiveness for prevention of varicella when administered after exposure among children <13 years of age.

RESULTS

Sixty-seven shelter residents received varicella vaccine after exposure, including 42 children <13 years of age. One child who was unvaccinated developed varicella, but no vaccinated child developed typical disease. Vaccine effectiveness was 95.2% (95% CI, 81.6%-98.8%) for prevention of any disease and 100% for prevention of moderate or severe disease among the children <13 years of age.

CONCLUSION

When used within 36 hours after exposure to varicella in a setting where close contact occurred, varicella vaccine was highly effective in preventing further disease. This study provides support for the recent recommendation by the Advisory Committee on Immunization Practices to administer varicella vaccine after exposure: this practice should minimize the number of moderate or severe cases of disease and prevent prolonged outbreaks.

Rescue of fatal neonatal hemorrhage in factor V deficient mice by low level transgene expression

Factor V (FV) is a critical component of the coagulation cascade. FV-deficient patients suffer moderate to severe bleeding, though residual FV activity is detectable in nearly all cases. In contrast, FV-deficient mice die either during mid-embryogenesis, or of massive perinatal hemorrhage. In order to examine the requirements for FV in murine embryogenesis and hemostasis, we generated transgenic mouse lines expressing a Fv minigene under control of either the tissue-specific albumin (Malb) or rat platelet factor 4 (Rpf4) promoter. A total of 12 Malb and 3 Rpf4 lines were analyzed. Though expression in the target tissue was detectable in most lines by RT-PCR, only low levels of transgene expression were achieved (<3% of endogenous Fv in all lines). Despite a low level of Fv transgene expression, rescue of the lethal Fv-/- phenotype was observed with one of the Malb transgenic (Tg+) lines. However, rescue appeared to be incomplete with continued loss of >1/2 of expected Tg+,Fv-/- mice in early embryogenesis. Rescued Tg+,Fv-/- mice have undetectable FV (<0.1%) in both plasma and platelet compartments, but survive the perinatal period and mature to adulthood without spontaneous hemorrhage. We conclude that FV present at <0.1% is sufficient to support postnatal survival. Failure of the Malb transgene to rescue the midembryonic block suggests that FV expression is required during mammalian development at higher levels or with a different tissue-specific or temporal pattern. Taken together, these data may explain the observation of residual FV activity in most human FV-deficient patients due to early embryonic lethality in those absolutely deficient, and suggest that minimal levels of FV expression, below the level of detection, also may be sufficient to support survival in humans.

Expression and cellular localization of interleukin-6 mRNA in ovariectomized rats

In order to observe the expression and cellular localization of interleukin-6 (IL-6) mRNA in bone tissue, ovaries of the rats were excised to develop osteoporosis model. The expression of IL-6 mRNA in bone tissues was detected by using dot blot hybridization assay and the cells producing IL-6 identified and localized by using in situ hybridization respectively. The results showed that the expression of IL-6 mRNA was significantly increased in the ovariectomized rats as compared with that in normal control rats and strong IL-6 mRNA hybridization signals were detected in lining cells, osteoblasts and osteocytes. It was suggested that loss of ovarian function induced in vivo osteoblast lineage increased IL-6 mRNA expression. IL-6 might play important roles in the development of bone loss following ovariectomy.

Molecular mass distribution of sodium alginate by high-performance size-exclusion chromatography

A sensitive high-performance size-exclusion chromatography (HPSEC) method with simple UV detection was developed for the molecular mass analysis of sodium alginate. It was used to evaluate alginates of varying molecular mass and the results were compared with the viscosity measurements. This HPSEC method was sensitive to serve as the stability indicating method for alginate after storage under different conditions. The information of relative molecular mass distribution of alginate was provided with reference to pullulan molecular mass standards. The comparison of the HPSEC chromatograms of alginate, pullulan and dextran revealed the effect of chemical composition of a polysaccharide and its effect on apparent molecular mass distribution.

Association of p63 with proliferative potential in normal and neoplastic human keratinocytes

p63, a recently identified member of the p53 gene family, encodes multiple products with transactivating, death-inducing, and dominant-negative activities. We show that in normal human epidermis, in hair follicles, and in stratified epidermal cultures, p63 protein is principally restricted to cells with high proliferative potential and is absent from the cells that are undergoing terminal differentiation. In normal human epidermis and in hair follicles, basal cells with abundant p63 are interspersed with cells with little or no p63. Whenever p63 mRNA is present, it encodes mainly truncated, potentially dominant-negative isotypes. In squamous cell carcinomas, the number of cells containing p63 and their distribution depends on the degree of anaplasia. In highly differentiated tumors, p63 is confined to a ring of basal-like cells surrounding, but at a distance from, centers of terminal differentiation. In less differentiated tumors, most cells contain p63 and their distribution is chaotic with respect to centers of terminal differentiation. p63 appears to be a valuable diagnostic marker for anaplastic keratinocytes.

[Wavelength selection in management of central serous chorioretinopathy]

OBJECTIVE

To compare the effects of three kinds of laser wavelength in management of central serous chorioretinopathy (CSCR).

METHOD

89 patients with CSCR were randomly divided into three groups according to different wavelengths used. Visual acuity, fundus, fundus fluorescein angiography (FFA), light sensitivity, central visual field were performed before and after laser therapy.

RESULT

Compared with red and green wavelength groups, in yellow group the visual acuity, light sensitivity were improved more significantly (P < 0.05), and the disease course was shortened, the effects in recurrence rate were similar in the three wavelength groups.

CONCLUSION

In the three kinds of waves, yellow and red have similar and positive effects in the treatment of CSCR.

Heterozygous germline mutations in the p53 homolog p63 are the cause of EEC syndrome

EEC syndrome is an autosomal dominant disorder characterized by ectrodactyly, ectodermal dysplasia, and facial clefts. We have mapped the genetic defect in several EEC syndrome families to a region of chromosome 3q27 previously implicated in the EEC-like disorder, limb mammary syndrome (LMS). Analysis of the p63 gene, a homolog of p53 located in the critical LMS/EEC interval, revealed heterozygous mutations in nine unrelated EEC families. Eight mutations result in amino acid substitutions that are predicted to abolish the DNA binding capacity of p63. The ninth is a frameshift mutation that affects the p63alpha, but not p63beta and p63gamma isotypes. Transactivation studies with these mutant p63 isotypes provide a molecular explanation for the dominant character of p63 mutations in EEC syndrome.

Delta9 desaturase activity in bovine subcutaneous adipose tissue of different fatty acid composition

Two experiments were conducted to investigate the relationship between delta9 desaturase (stearoyl-coenzyme A desaturase) activity and fatty acid composition in subcutaneous adipose tissue from cattle of different backgrounds. In Experiment 1, subcutaneous adipose tissue samples were taken from carcasses of pasture-fed cattle and feedlot cattle fed for 100, 200, or 300 d. Adipose tissue from pasture-fed cattle had significantly lower total saturated fatty acids and higher total unsaturated fatty acids than feedlot cattle. Desaturase activity correspondingly was 60-85% higher in pasture-fed cattle than in feedlot cattle. There was no difference in the fatty acid composition or desaturase activity among samples from the 100-, 200-, and 300-d feedlot cattle. In Experiment 2, adipose tissue samples were collected from carcasses of feedlot cattle fed for 180 d with either a standard feedlot ration (control group), or a ration containing rumen-protected cottonseed oil (CSO) for the last 70-80 d. Adipose tissue from the CSO-fed cattle was more saturated than that from the control group, having significantly more 18:0 and less 16:1 and 18:1. Correspondingly, adipose tissue from the CSO group had significantly lower desaturase activity. The elevated 18:2 in adipose tissue from the CSO group confirmed that unsaturated fatty acids (including cyclopropenoid fatty acids) were protected from biohydrogenation. Further studies are needed to determine whether the repression of desaturase activity results from direct inhibition by cyclopropenoic acids or by higher dietary contents of 18:2.

Heterosis and developmental stability of body and organ weights at hatch for parental line broiler breeders and specific crosses among them

Body, yolk sac, left and right shanks with toes, empty left and right ceca, left and right lungs, heart, and bursa of Fabricius weights were obtained at hatch for 50 chicks from each of five commercial broiler parental lines (three sire and two dam) and three F1 crosses involving them. Differences among stocks and between sexes were inconsistent among mating combinations. Although correlation coefficients between yolk-free chick weight with organ weights were generally stock specific, they were high (> 0.75) with shank weight, intermediate with heart and lung weights, and low (< 0.25) with ceca and bursa weights. Heart:lung ratios of all F1 crosses were greater than those for their respective parental lines; however, the degree of heterosis differed among populations. Developmental stability, as measured by percentage relative asymmetry, was less in two of the sire parental lines than in their respective dam lines and F1 crosses.

[Research into the mechanism of fragile sealing on the composition packet]

The research into the fragility of the sealing on two composition films for ham packages by using Fourier infrared spectrometer, DTG and melting index detector is reported. The research shows that the cause of the fragility of the sealing is the differences in the materials and their softening points and melting indexes between the inner film and the outer film. The inner film is made of adhesive polypropylene, whose softening point is 148.8 degrees C and melting index (MI) is 6.049 g/10 min. However, the outer film is made of polyamide 610, whose softening point is 221 degrees C, 72.2 degrees C higher than that of inner film, and melting index is 3.09 g/10 min, almost half of the MI of inner film. The mechanism of the fragile sealing on the composition packet is also discussed.

Analysis of temporal wear patterns of porous-coated acetabular components: distinguishing between true wear and so-called bedding-in

BACKGROUND

Standard radiographic assessment of penetration by the femoral head into a polyethylene liner does not enable clinicians to distinguish between the two processes that cause movement of the head: true wear (the removal of polyethylene particles) and so-called bedding-in (other factors, such as creep and settling-in of the liner). By analyzing radiographs made over time, researchers can distinguish true wear from the bedding-in process. The purpose of the current study was to compare the wear performance of the initial modular acetabular cup design (so-called first-generation components) of three different manufacturers with that of a so-called second-generation component made by one of the manufacturers.

METHODS

A two-dimensional computerized radiographic method was used to analyze 1300 radiographs of 315 hips that were followed for 3.0 to 10.5 years. Temporal penetration by the head in the three groups of first-generation cups was compared with penetration in the group of second-generation cups. Multiple linear regression analysis was used to model penetration-versus-time data as a line for each group. The slope of each regression line indicated the true rate of wear, and the intercept of the regression line indicated the amount of bedding-in.

RESULTS

Modifications in the design of the second-generation components, including thicker polyethylene and an improved locking mechanism, led to a decrease in the mean penetration by the head; however, the second-generation component did not have a lower true rate of wear than two of the first-generation components. Rather, the decreased penetration by the head into the second-generation component resulted from decreased bedding-in of the liner.

CONCLUSIONS

These findings and this technique of analysis are clinically relevant to surgeons who evaluate polyethylene wear radiographically. First, penetration by the head in the early postoperative years might not be due entirely to abrasive wear of the polyethylene liner but, rather, to a change in the position of the head resulting from the bedding-in process. The inclusion of bedding-in in calculations of wear artificially inflates the rate of wear and may result in a misrepresentation of the potential risk of wear-related complications. This is especially true with regard to comparisons of different designs of modular cups, in which conformity and tolerances between the polyethylene liner and the metal shell can vary greatly. Second, analysis of penetration by the head at multiple time-intervals can be used to distinguish true polyethylene wear from the bedding-in process. Such an analysis allows more accurate determination of the true rates of wear of different designs of modular cups and, therefore, of potential wear-related complications.

Frequency of the fragile X syndrome in Chinese mentally retarded populations is similar to that in Caucasians

Fragile X syndrome is recognized as the most common inherited cause of mental retardation in western countries. The prevalence of the fragile X syndrome in Asian populations is uncertain. We report a multi-institutional collaborative study of molecular screening for the fragile X syndrome from 1,127 Chinese mentally retarded (MR) individuals. We found that 2.8% of the Chinese MR population screened by DNA analysis had the fragile X full mutation. Our screening indicated that the fragile X syndrome prevalence was very close to that of Caucasian subjects. In addition, we found that 62.5% of fragile X chromosomes had a single haplotype for DXS548-FRAXAC1 (21-18 repeats) which was present in only 9.7% of controls. This unique distribution of microsatellite markers flanking the FMR1 CGG repeats suggests that the fragile X syndrome in Chinese populations, as in the Caucasian, may also be derived from founder chromosomes.

p63 is essential for regenerative proliferation in limb, craniofacial and epithelial development

The p63 gene, a homologue of the tumour-suppressor p53, is highly expressed in the basal or progenitor layers of many epithelial tissues. Here we report that mice homozygous for a disrupted p63 gene have major defects in their limb, craniofacial and epithelial development. p63 is expressed in the ectodermal surfaces of the limb buds, branchial arches and epidermal appendages, which are all sites of reciprocal signalling that direct morphogenetic patterning of the underlying mesoderm. The limb truncations are due to a failure to maintain the apical ectodermal ridge, a stratified epithelium, essential for limb development. The embryonic epidermis of p63-/- mice undergoes an unusual process of non-regenerative differentiation, culminating in a striking absence of all squamous epithelia and their derivatives, including mammary, lacrymal and salivary glands. Taken together, our results indicate that p63 is critical for maintaining the progenitor-cell populations that are necessary to sustain epithelial development and morphogenesis.

ERGIC-53 gene structure and mutation analysis in 19 combined factors V and VIII deficiency families

Combined factors V and VIII deficiency is an autosomal recessive bleeding disorder associated with plasma levels of coagulation factors V and VIII approximately 5% to 30% of normal. The disease gene was recently identified as the endoplasmic reticulum-Golgi intermediate compartment protein ERGIC-53 by positional cloning, with the detection of two founder mutations in 10 Jewish families. To identify mutations in additional families, the structure of the ERGIC-53 gene was determined by genomic polymerase chain reaction (PCR) and sequence analysis of bacterial artificial chromosome clones containing the ERGIC-53 gene. Nineteen additional families were analyzed by direct sequence analysis of the entire coding region and the intron/exon junctions. Seven novel mutations were identified in 10 families, with one additional family found to harbor one of the two previously described mutations. All of the identified mutations would be predicted to result in complete absence of functional ERGIC-53 protein. In 8 of 19 families, no mutation was identified. Genotyping data indicate that at least two of these families are not linked to the ERGIC-53 locus. Taken together, these results suggest that a significant subset of combined factors V and VIII deficiency is due to mutation in one or more additional genes.

A rapid screening and diagnosis on fragile X syndrome by PCR

Polymerase chain reaction (PCR) technique combined with direct detection by silver staining on denaturing DNA sequencing gel was used to analyze the (CGG)n repeats within the FMR1 gene on 169 suspected patients with mental retardation and 33 kindreds of 6 fragile X families. The results showed that: (1) No PCR products were detected in 3 males in the suspected group. (2) In the fragile X family studies, the 5 male probands failed to show any PCR products. (3) Diplex PCR with the primers flanking the FRAXE locus was used to serve as an internal control for the 8 above-mentioned males and only normal products of the FRAXE locus were detected, indicating that the possibility of false negative results of the FRAXA locus could be eliminated. These findings suggested that analysis of (CGG)n repeat within the FMR1 gene by PCR technique could efficiently detect premutation carriers and that negative PCR products in mentally retarded males might highly imply the diagnosis of fragile X syndrome after the false negative results have been excluded by diplex PCR. This PCR assay is suitable for the screening and diagnosis of fragile X syndrome in a large number of populations due to its rapidity, simplicity, stability and reliability.

[Experimental evaluation of the antibacterial activity of tomato pulp oil extract]

The antibacterial action of the oil extract obtained from tomato pulp has been studied with the use of museum strains Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 5638-P and Candida albicans ATCC 885-653, recommended for the determination of the antibacterial activity of medicinal preparations (State Pharmacopoeia, edition XI), as well as Enterobacter, Streptococcus, Staphylococcus, Klebsiella and Escherichia clinical strains. As revealed in this study, tomato pulp oil extract produces a wide-spectrum antibacterial effect on Gram-positive and Gram-negative microorganisms and on fungi of the genus Candida. The study has determined that this antibacterial action is linked with the presence of a complex of organic acids (succinic, citric, tartaric, etc.).

From airports to care centers. Transferring information technology to support patient care reengineering

PROBLEM

To improve communication among caregivers about the status of patients under their care.

SOLUTION

Replacing manual white boards with electronic bed boards/inpatient databases, similar to airport display technology.

RESULTS

Improved data quality from having patient data displayed in a standardized manner across care centers.

KEYS TO SUCCESS

"We used a process redesign team, which focused on specific issues related to the processes used in providing patient care."

At least four loci and gender are associated with susceptibility to the chemical induction of lung adenomas in A/J x BALB/c mice

Four putative quantitative trait loci (QTLs) that influence susceptibility to the induction of lung adenomas by urethane in an F2 cross between A/J and BALB/cOlaHsd have been mapped. Following microsatellite typing of mice with resistant and susceptible phenotypes at 97 microsatellite marker loci, a major locus was identified on chromosome 18 with a lod score of 15. This was responsible for an 8- to 10-fold increase in tumor multiplicity in males and females, respectively, having the AA and CC genotypes at the D18Mit188 marker locus. It mapped close to Dcc (deleted in colorectal cancer). A locus on chromosome 4 (lod score 6.5) had the resistant allele in strain A/J and the susceptible allele in BALB/c, with a 14-fold difference in tumor multiplicity between mice of the AA and CC genotypes. This mapped close to the Cdkn2a (cyclin-dependent kinase inhibitor 2A) locus, which is commonly deleted in mouse lung tumors. Two loci with smaller effects (lod scores 3.03 and 3.25) were identified on chromosomes 1 and 11. There was also significant sexual dimorphism in tumor multiplicity both among 151 F2 hybrids and among 52 mice resulting from a backcross to strain A/J, with males having higher tumor counts than females.

p63, a p53 homolog at 3q27-29, encodes multiple products with transactivating, death-inducing, and dominant-negative activities

We describe the cloning of p63, a gene at chromosome 3q27-29 that bears strong homology to the tumor suppressor p53 and to the related gene, p73. p63 was detected in a variety of human and mouse tissues, including proliferating basal cells of epithelial layers in the epidermis, cervix, urothelium, and prostate. Unlike p53, the p63 gene encodes multiple isotypes with remarkably divergent abilities to transactivate p53 reporter genes and induce apoptosis. Importantly, the predominant p63 isotypes in many epithelial tissues lack an acidic N terminus corresponding to the transactivation domain of p53. We demonstrate that these truncated p63 variants can act as dominant-negative agents toward transactivation by p53 and p63, and we suggest the possibility of physiological interactions among members of the p53 family.

Mode of inheritance of unselected traits in lines of chickens selected for high or low antibody response to sheep red blood cells. 1. Resistance to marble spleen disease virus and juvenile body weight

Two lines of White Leghorns that had undergone long-term selection for high (HH) or low (LL) antibody response to sheep red blood cell antigen(s) formed the nuclear lines for this experiment. Matings were made in a full diallel cross to produce in a single hatch from age-contemporary breeders the parental lines, reciprocal F1 and F2 crosses, and backcrosses for 16 progeny types. For males and females, there were parental line differences in BW to 42 d of age, after which there was decline between lines for males. Differences in BW between reciprocal F1 crosses and maternal heterosis declined with age, primarily reflecting dissipation of effects of egg weight. Heterosis of BW was dependent on the particular F1 cross and recombination effects were not important. At 50 d of age chicks were inoculated with either a 1 or 10% suspension of spleen extract from chickens infected with marble spleen disease virus (MSDV). A third group served as uninjected controls. Response to MSDV was evaluated by spleen weight 6 d after inoculation. Spleen weights relative to BW of control chicks were heavier for the HH than LL line with evidence from the crosses of sexlinkage and negative heterosis. Line LL chicks were more resistant to MSDV than Line HH chicks was F1 crosses intermediate to and different from either parental line with no evidence of heterosis.

Mode of inheritance of unselected traits in lines of chickens selected for high or low antibody response to sheep red blood cells. 2. Heterophils, lymphocytes, and hematocrits

The nuclear lines for this experiment were White Leghorns that had undergone long-term selection for high (HH) or low (LL) antibody response to sheep red blood cell antigen(s). Sixteen progeny types consisting of parental lines, reciprocal F1 and F2 crosses, and backcrosses were produced in a single hatch from age-contemporary parents. At 30 d of age, blood was obtained from a random sample of 10 males per progeny type (n = 160) and slides prepared for subsequent determination of number of heterophils and lymphocytes. Twelve days later, blood was collected from random samples of 10 males and 10 females per progeny type (n = 320) for measuring hematocrits. There were no differences between parental lines for heterophils, lymphocytes, or the heterophil:lymphocyte ratio. Reciprocal effects were evident in the F1 crosses and directional heterosis was present in one cross but not the other. Neither maternal heterosis nor recombination effects were significant for either heterophils or lymphocytes. Although hematocrits were similar for males and females and parental lines, sex-linked and recombination effects appeared to be important.

Additional evidence that the K-ras protooncogene is a candidate for the major mouse pulmonary adenoma susceptibility (Pas-1) gene

A locus for mouse pulmonary adenoma susceptibility, Pas-1, has been mapped on distal chromosome 6, where the K-ras gene is located. Allele-specific activation and expression of the K-ras allele from the susceptible parent has been observed in lung tumors from F1 hybrid mice. We report here genetic mapping of lung tumor susceptibility genes in urethane-treated A x B and B x A recombinant inbred (RI) mice using microsatellite markers to seek further evidence for the K-ras gene as candidate for Pas-1. The K-ras genotype differs between the A/J and C57BL/6J progenitors of the RI strains, and distal chromosome 6 contained a major lung tumor susceptibility determinant in the RI mice. Additional evidence that Pas-1 is K-ras involved linkage analysis of (A/JOLaHsd x BALB/ cOLaHsd) F2 intercross mice whose parents shared the same K-ras genotype. In contrast to the results with the A x B and B x A RI strains, no distal chromosome 6 site was significantly associated with tumor development in these F2 mice. In addition to this major locus, linkage analysis of the RI mice revealed additional quantitative trait loci for susceptibility on chromosomes 10, 17, and 19. These loci may serve as modifiers of Pas-1. The relationship between the K-ras genotype and the frequency of K-ras mutations in urethane-induced lung tumors from the RI mice was also explored. All 18 tumor DNAs from RI mice with high susceptibility contained an AT-->TA transversion at the second base of K-ras codon 61. This was also true for DNAs from 27 of 27 (100%) tumors in mice with high intermediate susceptibility. In RI strains with a low intermediate susceptibility, the DNA from 39 of 47 (83%) tumors contained an AT-->TA transversion at codon 61, and only 13 of 21 (62%) tumors had this mutation in the most resistant group. This reflects a positive correlation between the frequency of K-ras mutations in lung tumors of A x B or B x A RI strains and their susceptibility to lung carcinogenesis. Since K-ras appears to be Pas-1, these results suggest that some RI mice that have the resistant K-ras or Pas-1 allele undergo tumor development by a K-ras-independent route.

The structure and function of murine factor V and its inactivation by protein C

Factor V (FV) is a central regulator of hemostasis, serving both as a critical cofactor for the prothrombinase activity of factor Xa and the target for proteolytic inactivation by the anticoagulant, activated protein C (APC). To examine the evolutionary conservation of FV procoagulant activity and functional inactivation by APC, we cloned and sequenced the coding region of murine FV cDNA and generated recombinant wild-type and mutant murine FV proteins. The murine FV cDNA encodes a 2,183-amino acid protein. Sequence comparison shows that the A1-A3 and C1-C2 domains of FV are highly conserved, demonstrating greater than 84% sequence identity between murine and human, and 60% overall amino acid identity among human, bovine, and murine FV sequences. In contrast, only 35% identity among all three species is observed for the poorly conserved B domain. The arginines at all thrombin cleavage sites and the R305 and R504 APC cleavage sites (corresponding to amino acid residues R306 and R506 in human FV) are invariant in all three species. Point mutants were generated to substitute glutamine at R305, R504, or both (R305/R504). Wild-type and all three mutant FV recombinant proteins show equivalent FV procoagulant activity. Single mutations at R305 or R504 result in partial resistance of FV to APC inactivation, whereas recombinant murine FV carrying both mutations (R305Q/R504Q) is nearly completely APC resistant. Thus, the structure and function of FV and its interaction with APC are highly conserved across mammalian species.

[Detection of minimal residual disease in acute lymphoblastic leukemia using PCR-molecule hybridization of RNA transcripts]

OBJECTIVE

To detect acute lymphoblastic leukemia's(ALL's) minimal residual disease(MRD) rapidly and effectively.

METHODS

In this assay, the gamma T-cell receptor gene rearrangements serve as marker genes. The gene rearrangements are amplified from the diagnostic specimens using a consensus V segment primer and a consensus J segment primer to which the promoter T7 RNA polymerase has been appended. The PCR product from this amplification is transcribed into a radiolabeled RNA probe. The opposite DNA strand is transcribed into test RNA from the PCR product of different staged specimens. The test RNA is hybridized with the probe, and later the digestion with RNase A, Polyacrylamide gel electrophoresis and autoradiography are in progress.

RESULTS

According to the mechanism, the perfectly matched RNA duplex can prevent the digestion of RNase A, and the presence of the leukemia cells in the test specimen can be determined. Logarithmical dilution experiments with DNA of a cell line from ALL have shown that this assay's sensitivity is at the 10(-5) level. Minimal residual disease was successfully detected in a case of ALL during its complete remission stage. But if the probe and test RNA are not from the same individual, the results of this kind of cross hybridization are negative.

CONCLUSION

The above results suggest that this assay can become an effective measure in the detection of ALL-MRD clinically.

Studies on diffusion maximum in x-ray diffraction patterns of plasma-sprayed hydroxyapatite coatings

Study of an amorphous phase in plasma-sprayed hydroxyapatite (HA) coatings is important owing to its unique characteristics and nonnegligible amount of the amorphous phase compared to crystalline HA. However, little is known about the component parts of an amorphous phase. It is known that amorphous phase usually appears as the diffusion maximum (Dmax) in X-ray diffraction (XRD) patterns. Analyzing Dmax, including the position (Pmax) and area of Dmax, we can indicate the component parts of an amorphous phase and their transitions. In this study, the variation of Dmax in XRD patterns of the coatings during plasma spraying, in postheating, and in dissolving in vitro was studied with the aid of XRD. It was found that component parts of the amorphous phase in the coating varied with increasing thickness, consisting of two part represented by Dmax1, located between 29.4 and 29.8 degrees (2 theta), and Dmax2, located between 31.0 and 31.4 degrees (2 theta). It was concluded that Dmax3, located between 32.0 and 32.4 degrees (2 theta), should be referred to as nanocrystals of HA. In addition, the particle size of the starting powder may affect the component parts of the amorphous phase in the coating in addition to thickness. With vacuum heating (650 degrees C) and water vapor treatment at a low temperature (125 degrees C) in a saturated vaporic atmosphere, transition of the amorphous components was not as efficient as that at 490 degrees C with water vapor. The reason might be that the amorphous-to-crystalline HA conversion is dependent on both temperature and water vapor pressure. It was found that amorphous components were transformed completely into crystalline HA after heating at 490 degrees C with a partial water vapor pressure of 0.01 MPa for 2 h. It was concluded that the unstable amorphous components (Dmax1, Dmax2) converted into more stable nanocrystals of HA (Dmax3). Degradation in vitro showed that Dmax3 was more stable than Dmax1 and Dmax2. It was concluded that nucleation of apatite in vitro should be attributed to nanocrystals of HA (Dmax3) except for the amorphous components. It is recommended that the optimal phasic contents of the plasma-sprayed HA coating be mainly composed of crystalline HA and nanocrystals of HA (Dmax3) in terms of the stability and biocompatibility of the coating.

Developmental stability in different genetic stocks of white rock chickens

Asymmetries were determined for several bilateral traits in females from a line of chickens selected for 39 generations for low 56 day body weight (LWS) and in a subline of LWS where selection had been relaxed for four generations (LWR). Because of reduced food intake under ad libitum feeding, some LWS females do not commence egg production, a condition that can be overcome by relaxing selection for a generation or two. Bilateral traits, measured at 240 days of age in LWS non-layers, LWS layers, and LWR layers, were shank length and diameter, distance between the auditory canal and the posterior junction of the upper and lower mandible, and weight and length of the first primary wing feather. Other traits measured were body weights at 56, 168, and 240 days of age and age at first egg. Fluctuating asymmetry, a good overall measure of developmental stability, was lower in the relaxed than selected line. Means of relative asymmetries were also lower for LWR females than LWS layers and nonlayers which were similar.

Positional analysis of triacylglycerols from bovine adipose tissue lipids varying in degree of unsaturation

The objective of this study was to demonstrate that changing the fatty acid composition of bovine adipose tissue concurrently changed (i) proportions of triacylglycerol species, (ii) fatty acid composition of triacylglycerol species, and (iii) positional distribution of the component fatty acids of the triacylglycerol species. To achieve this, we took advantage of adipose tissue lipids, from cattle fed in Australia and Japan, that varied widely in fatty acid composition and melting points. Treatment groups produced in Australia were cattle fed: a cornbased diet (MUFA1); a grain-based diet containing whole cottonseed (SFA); a grain-based diet containing protected cottonseed oil (PUFA); and a grain-based diet that resulted in high contents of trans fatty acids (TFA). Treatment groups produced in Japan (MUFA2 and MUFA3) were diets of unknown composition fed for over 300 d. The MUFA1, MUFA2, and MUFA3 samples all were rich in monounsaturated fatty acids, varying only in the proportions of the individual monounsaturates. The SFA, PUFA, and TFA samples had relatively high concentrations of stearic acid (18:0), PUFA, and TFA, respectively. Slip points (indicative of melting points) were 45.1, 41.5, 38.5, 30.7, 28.4, and 22.8 degrees C, for the SFA, TFA, PUFA, MUFA1, MUFA2, and MUFA3 groups, respectively (P < 0.05). Triacylglycerols were separated by high-performance liquid chromatography on a silver nitrate-impregnated column into sn-1,2,3-saturated fatty acid triacylglycerol (SSS); [triacylglycerols containing two saturated acids and one trans-monounsaturated fatty acid (SMMt sn-positions unknown)]; sn-1-saturated, 2-monounsaturated, 3-saturated triacylglycerol (SMS); sn-1-saturated, 2-monounsaturated 3-trans-monounsaturated triacylglycerol (SMMt); sn-1-saturated, 2,3-monounsaturated fatty acid triacylglycerol (SMM); sn-1-saturated, 2-polyunsaturated, 3-trans-monounsaturated triacylglycerol; sn-1,2,3-monounsaturated fatty acid triacylglycerol (MMM); and sn-1-saturated, 2-polyunsaturated, 3-monounsaturated triacylglycerol. Fatty acid methyl esters of each triacylglycerol species also were determined, and further analysis indicated sn-2, and sn-1/3 positions. As the percentage oleic acid increased in the total lipid extract, the proportions of SMM and MMM increased (e.g., from 31.4 and 2.4% in the SFA group to 55.4 and 17.8% in the MUFA3 group). The elevated 18:0 in the SFA group (26%) was reflected in increased percentages of SSS and SSM, and caused an increase in the proportion of 18:0 in all triacylglycerol species relative to the other treatment groups. The percentage of 18:0 in the sn-1/3 positions was elevated markedly in the SMS fraction of the SFA group (to 44%); this would account for the high melting point of the fat of these animals. We conclude that long-term feeding of cattle is sufficient to produce significant alterations in fatty acid composition in bovine adipose tissue. Alterations in the fatty acid composition of bovine adipose tissue changed both the distribution and the composition of the triacylglycerol species, which, in turn, accounted for marked differences in melting points among treatment groups.

Detection of minimal leukemic cells in cerebral spinal fluid of children with acute lymphoblastic leukemia using the polymerase chain reaction technique

V delta 2D delta 3 rearrangements of T cell receptor (TCR) gene from cerebral-spinal fluid (CSF) cells was detected for diagnosis and monitoring of central nervous system leukemia (CNSL) in children with acute lymphoblastic leukemia (ALL) using polymerase chain reaction (PCR) technique. 20 patients were studied and in 12 of them the results of PCR and dot hybridization with clonospecific probes were positive, showing the presence of minimal blast cells in CSF. Our study suggested that the PCR method is an effective tool for clinical diagnosis of CNSL and is much more sensitive than routine CSF examination.

Changes in platelet size and count in unstable angina compared to stable angina or non-cardiac chest pain

AIMS

An increase in platelet aggregability is associated with unstable angina and myocardial infarction. Platelet size and activity correlate and mean platelet volume was found to be increased before acute myocardial infarction. We measured the mean platelet volume and platelet count in patients with stable angina, unstable angina and non-cardiac chest pain.

METHODS AND RESULTS

We studied 981 patients (734 men; 247 women) defined clinically as stable angina (n = 688), unstable angina (n = 108) and unstable angina requiring immediate angioplasty (n = 52). After coronary angiography the patients were subdivided into single (n = 269), double (n = 304) and triple-vessel disease (n = 311) and the control group of non-cardiac chest pain (n = 97). There was no significant difference in platelet count between the control group and patients with 1, 2, or 3-vessel disease. However, the platelet size in patients with coronary artery disease was significantly larger (single: 8.7 +/- 1.19 fl; double: 8.7 +/- 1.12 fl; triple-vessel disease: 8.8 +/- 1.18 fl) than the control group (8.2 +/- 0.95 fl) (P < 0.01). Patients with stable angina similarly had no, significant difference in platelet count compared to the control group but did have a significantly increased mean platelet volume (8.7 +/- 1.13; P < 0.01). In contrast, patients with unstable angina had a decreased platelet count (245 +/- 56 x 10/l) compared to either stable angina (262 +/- 62 x 10/l; P < 0.05) or the control group (261 +/- 58 x 10/l; P < 0.05); furthermore, the mean platelet volume (9.4 +/- 1.23 fl) was significantly greater than for stable angina (P < 0.01). Patients with unstable angina requiring immediate PTCA had an even lower platelet count (231 +/- 55 x 10/l) and higher mean platelet volume (10.4 +/- 1.03 fl) (P < 0.01) than the rest of the population with unstable angina.

CONCLUSIONS

In stable angina the platelet count is unchanged compared to patients with normal coronary arteries but the platelet size is increased. However, in unstable angina there is a decrease in platelet count and an even larger increase in platelet size. We interpret this as meaning that unstable angina might be associated or preceded by an increase in platelet destruction rate that is not completely compensated for by an increase in platelet production rate. The large, more reactive platelets might be causally related to an ongoing coronary artery obstruction in unstable angina.

Developmental stability in stocks of White Leghorn chickens

The degree of asymmetry in bilateral morphological characters may reflect genetic and environmental stressors. Shank length and diameter, weight and length of the first primary wing feather, and distance between the junction of upper and lower mandibles and auditory canal (face length) were used to classify bilateral types and measure relative asymmetry (RA) in six genetic stocks. The stocks were the S23 generation of White Leghorn lines selected for high or low antibody response to SRBC, sublines in which selection had been relaxed for eight generations, and reciprocal crosses of the selected lines. Differences were found among all stocks for the traits measured. Rankings among traits for RA in descending order were face length, shank diameter, feather weight, and shank and feather lengths. The RA of shank and feather lengths did not differ from each other. An overall RA composed of mean RA of the five traits showed that the two selected lines exhibited greater RA than the crosses between them. The RA of the two lines where selection had been relaxed was similar to that of selected lines. This research suggests that an overall RA created as a combination of RA of several bilateral traits can be a valid measure of genetic stress in chickens and provides a method of comparing developmental stability among populations.

Monoallelically expressed gene related to p53 at 1p36, a region frequently deleted in neuroblastoma and other human cancers

We describe a gene encoding p73, a protein that shares considerable homology with the tumor suppressor p53. p73 maps to 1p36, a region frequently deleted in neuroblastoma and other tumors and thought to contain multiple tumor suppressor genes. Our analysis of neuroblastoma cell lines with 1p and p73 loss of heterozygosity failed to detect coding sequence mutations in remaining p73 alleles. However, the demonstration that p73 is monoallelically expressed supports the notion that it is a candidate gene in neuroblastoma. p73 also has the potential to activate p53 target genes and to interact with p53. We propose that the disregulation of p73 contributes to tumorigenesis and that p53-related proteins operate in a network of developmental and cell cycle controls.

Penile length in adulthood after exstrophy reconstruction

PURPOSE

We attempted to determine whether the penis in adulthood after exstrophy reconstruction is short because of a congenital defect in the size of the corpora cavernosa.

MATERIALS AND METHODS

Pelvic magnetic resonance imaging was performed on 10 men who underwent exstrophy reconstruction in childhood, and 10 age and race matched controls. Measurements of penile and pelvic anatomy were compared.

RESULTS

The corpora cavernosa in men after exstrophy reconstruction were shorter than normal. Dividing total corporeal length into an anterior and posterior segment revealed that the anterior segment was short but the posterior segment attached to the pubic ramus was normal. However, the diameter of the posterior corporeal segment was greater than in controls. Although diastasis of the symphysis pubis increased the intersymphyseal and intercorporeal distances, the angle between the corpora cavernosa was unchanged, presumably because the corporeal bodies were separated in a parallel fashion.

CONCLUSIONS

After exstrophy reconstruction the penis is short in adulthood, at least partially due to a congenital deficiency of corporeal tissue. Since diastasis of the pubic symphysis and chordee decrease penile visibility, approximation of the pubic symphysis and procedures to straighten the penis may improve cosmesis. However, because the corpora cavernosa are short, after exstrophy reconstruction the penis will always be shorter than normal in adulthood.

Late embryonic and early posthatch growth of heart and lung in White Leghorn lines of chickens

Growth and development of heart and lungs were measured from day 15 of incubation to 25 days after hatch in lines of chickens that had undergone long-term selection for high (HAS) or low (LAS) antibody titers to sheep erythrocytes. A correlated response to this selection was heavier 28-day body weights for LAS than HAS chickens. In this experiment body weights were heavier in line LAS than HAS from 15 days of incubation to 5 days after hatch and again at 25 days after hatch. Absorption of residual yolk was greater in HAS than LAS chicks. Although there were no differences between lines for absolute heart weights, lungs were heavier in line LAS than HAS at all ages except 20 days after hatch. Relative to body weight, both heart and lung weights declined with age, however, the pattern of decline differed. For this criterium, hearts were larger in line HAS than LAS to 5 days after hatch with no difference thereafter; for lungs lines were similar until 5 days after hatch after which they were larger in LAS than HAS chicks. In all but one case (HAS at hatch) the left:right relationship for lung weights exhibited fluctuating asymmetry with the left minus right character difference having a normal distribution and mean zero. The degree of fluctuating asymmetry, however, varied with age.

The study of DNA oxidative damage in benzene-exposed workers

Peripheral blood lymphocyte 8-hydroxy-2-deoxyguanosine (8-OHdG), were detected in 87 benzene-exposed and 30 control subjects by high performance liquid chromatograph coupled with an electrochemical detector system (HPLC-EC). The air concentration of benzene and its homologes in the workplace, urinary trans,trans-muconic acid (TTMA) as an internal dose of benzene exposure, were examined. The lymphocyte micronuclei (MN) as genotoxic and white blood cell (WBC) count as well as the myelotoxic markers of benzene were examined. Exposure to low, medium and high concentrations of benzene resulted in increased levels of 8-OHdG, which were 4.67, 26.12 and 29.89/10(5) dG, respectively, However, the 8-OHdG level observed in the control group was 3.738/10(5) dG). A good correlation between 8-OHdG formation and the groups exposed to external and internal benzene was observed (r = 0.77, 0.64, respectively). There was also a correlation between 8-OHdG and MN formation (r = 0.50). WBC levels were within normal range in all benzene-exposed subjects. It may be concluded that: benzene induced DNA oxidative damage in occupational exposure workers. The major factors influencing blood the 8-OHdG level were sex and toluene.

Anatomic goals in the correction of female stress urinary incontinence

The goal of stress incontinence surgery is to prevent opening of the urethra during increases in intra-abdominal pressure. Greater refinements in the understanding of the pathophysiology of incontinence and experience with newer treatments have extended surgical thinking beyond the familiar paradigm "to place the urethra in a high retropubic position." When incontinence is associated with vaginal hypermobility, vaginal support may be sufficient to restore continence if the suburethral vaginal wall is sufficiently strong, an evaluation which must often be made by physical examination alone. However, when the vaginal wall is weak, the urethra will require an alternative form of support, usually a sling. If the urethra is intrinsically deficient, vaginal support may not be sufficient to prevent opening during increased intra-abdominal pressure, and coaptation by sling obstruction or periurethral bulking injection may be required. Most laparoscopic approaches to stress incontinence use Burch's method, which offers excellent urethral stability provided the suburethral vaginal wall is strong. Newer insights into the relation between vaginal mobility and urethral closure are discussed, as well as anatomic aspects of the Burch suspension relevant to laparoscopic repair.

Editing efficiency of hepatitis delta virus RNA is related to the course of infection in woodchucks

Based on evidence in vitro which shows that the small form of hepatitis delta virus (HDV) antigen (S-HDAg) initiates virus replication, whereas the long form (L-HDAg) encoded by the edited L-genome inhibits replication, we first put forward the hypothesis that HDV RNA editing efficiency, i.e. the intracellular L/S-genome ratio, could be a determining factor on the course of the infection. In order to analyse the precise sequence of events after infection, woodchuck carriers of woodchuck hepatitis virus (WHV) were superinfected with HDV and sequential changes in HDV RNA editing efficiency were analysed in relation to the duration of viraemia. Our findings show that: (1) in both transiently and persistently viraemic woodchucks, the percentage of L-genome is higher at the early stage of onset of the disease than at the late stage; (2) at the early stage of onset the percentage of L-genome is higher in cases with transient viraemia than in those with persistent viraemia; (3) a relatively greater decrease in L-genome is seen later in transiently viraemic animals than in those that remain persistently viraemic. In view of the above findings in vivo and other supporting evidence in vitro, we propose a hypothesis for the pathogenesis of HDV. This hypothesis predicts the outcome of acute infection and we suggest a gene therapeutic approach for this disease based on the intracellular accumulation (or increase) of the L-genome.

[The role of endoscopic ultrasonography and epidermal growth factor receptor assay in preoperative staging for gastric carcinoma]

Endoscopic ultrasonography (EUS) was performed in 36 patients with gastric carcinoma and the epidermal growth factor receptor (EGFR) of the specimen from endoscopic biopsy in 19 patients with gastric carcinoma was measured with immunoassay. Results of EUS were compared to the pathology of resected specimens according to the new (1987) TNM classification. EUS was very accurate in assessing the depth of tumor infiltration and the lymph node metastasis. Overall accuracy in T and N stage were 81% and 72% respectively. The level of EGFR in patients with infiltration into the neighbouring organs (97.7 +/- 27.9 fmol/mg pro.) were significantly higher than those without infiltration (47.7 +/- 21.3 fmol/mg pro.) (P < 0.01). The EGFR levels of those with lymph node metastasis (85 +/- 24.3 fmol/mg pro.) were significantly higher than that without lymph node metastasis (37.1 +/- 16.1 fmol/mg pro.) (P < 0.01). The results show that EUS as well as the EGFR assay could be used to determine the progress and prognosis of gastric carcinoma.

Monocryl suture, a new ultra-pliable absorbable monofilament suture

Synthetic absorbable sutures are available as braided constructions or as monofilaments. Braided absorbable sutures are made either from 90:10 poly(glycolide-co-L(-)-lactide), sold by Ethicon, Inc. under the trade name Vicryl, or from polyglycolide, as sold, for instance, by Davis and Geck under the trade name Dexon. There are, however, some concerns with braided sutures that relate to tissue drag and the trauma this may cause, as well as the possible potentiation of infection through the interstices of the braid structure. Absorbable monofilaments, such as the monofilament sutures derived from p-dioxanone homopolymer (PDS II, an Ethicon, Inc. product), or a copolymer of trimethylene carbonate and glycolide (Maxon, a Davis and Geck product), eliminate many of these concerns, but generally monofilaments do not handle as well as braids. This paper describes the research leading to the introduction of Monocryl (poliglecaprone 25) monofilament sutures, based on segmented block copolymers of epsilon-caprolactone and glycolide. Monocryl sutures will be shown to display excellent handling properties, minimal resistance during passage through tissue and excellent tensile properties. These sutures provide an in vivo breaking strength retention of approximately 20-30% after 2 weeks, considered by many to be the critical wound healing period. Absorption data on these sutures are presented; absorption is complete between the 91st and 119th days of implantation, with slight or minimal tissue reaction.

[Adjustable reconditioner for the treatment of patella fracture]

Patella fracture belongs to the articular fracture. The operative methods to fix the patella fracture are numerous and there is no unanimous view. In order to protect the reconditioned patella, usually it is necessary to fix externally for a period of time. Since 1989, the authors have treated 165 cases of patella fracture with self designed, adjustable reconditioner and have acquired satisfactory results both in its fixing effect and function recovery. There was no need to fix the patella externally and the patients could do functional training in early stage. According to the assessment of the postoperative function and the motion limits of the knee and rehabilitation of the fracture, the results of the treatment were: excellent in 148 cases and good in 17 cases. This article describes the fixing mechanism of the reconditioner. It consists of the left and right petals and a screw. According to different sizes of patella and various types of the fracture, the reconditioner could be adjusted to connect the fracture closely with the petals and a screw. The structure of the reconditioner is simple, the operation is easy to carry out. It is adjustable during the operation and holds the fracture firmly and secure. It is suitable for all kinds of patella fracture avoiding partial or total resection of the patella. The other facture of the reconditioner is that the fixed patella could bear traction force when bending the knee at 90 degrees, so the patient could walk and squat on the heels normally.