COP Groups Research Articles

A long-term retrospective analysis of management of cervical cancer during pregnancy.

This study aims to describe cervical cancer during pregnancy (CCP) and investigate factors associated with survival outcomes. This retrospective matched study included CCP patients from May 2007 to August 2021 and matched non-pregnant cervical cancer patients (1:2) based on age (±5 years), year at diagnosis (±2 years), histological type and stage (2018 FIGO). The Kaplan-Meier method and multivariate Cox regression analyses were used to assess the impact of pregnancy and clinicopathologic factors on prognosis. Thirty-eight CCP patients (stage IA to IIIC) and 76 non-pregnant patients were included. Most CCP patients were diagnosed in the first (31.6%) or second (47.4%) trimester. CCP patients had a longer waiting time than non-pregnant patients. Pregnancy continued in 42.1% (continuation of pregnancy [COP] group) and was terminated in 57.9% (termination of pregnancy [TOP] group) of patients. Survival analysis showed no significant differences in recurrence-free survival (RFS) or overall survival (OS) between pregnant and non-pregnant patients or between the COP and TOP groups. At the end of the follow-up period (range 12-178 months), 23 children born to CCP patients exhibited normal development. Pregnancy does not impact cervical cancer prognosis. The oncologic outcomes of the TOP and COP groups were comparable. A pregnancy-preserving strategy could be considered for managing CCP patients.

Copers adopt an altered movement pattern compared to individuals with chronic ankle instability and control groups in unexpected single-leg landing and cutting task

Individuals with chronic ankle instability (CAI) demonstrate altered ankle kinematics during landing compared to uninjured individuals. However, if copers may have adopted unique movement strategy to prevent repeated ankle sprains is unclear. The purpose of this study compares the lower-extremity joint kinematics and muscle activities of CAI (N = 8), coper (COP) (N = 8), and control (CON) (N = 8) groups in unexpected single-leg landing and cutting. Performance time (from initial contact to toe-off), number of mistakes in the jumping direction, low-extremity joint angle are assessed. Muscle activities were recorded from the tibialis anterior, medial gastrocnemius, and peroneus longus (PL), and mean muscle activity, co-contraction index (CI), and PL latency were analyzed. Results of performance time and CI are not significant. Significantly less number of mistakes in the jumping direction and a shorter PL latency were discovered in the COP and CON compared with the CAI group (P < 0.05). The peak hip joint flexion angle is significantly smaller in the COP than in the CON (P = 0.04). In dynamic tasks requiring quick judgments of ankle inclination, the COP may be able to accurately sense the inclination of the foot. Additionally, movement strategies differed between the COP and CON groups in an unexpected single-leg landing and cutting.

Removal of copper and/or zinc ions from synthetic solutions by immobilized, non-viable bacterial biomass: Batch and fixed-bed column lab-scale study

A biosorbent composed of non-viable Pseudomonas putida trapped in agar beads was able to remove Cu2+ and Zn2+ from solutions containing one or both metals. The process in batch followed pseudo second-order kinetics, with adsorption capacities of 0.255 mg Cu2+/g and 0.170 mg Zn2+/g according to the Langmuir isotherm. These values were up to ten times lower for beads without biomass. The metals became bound to OH, CH2, CO, COC and COP groups, with the last three being provided by the biomass, which highlights its importance. Adsorption values for single-metal solutions filtered in a fixed-bed column were 0.152 mg Cu2+/g and 0.117 mg Zn2+/g, but decreased to 0.075 and 0.058, respectively, with mixed-metal solutions (1:1 ratio). In 10:1-ratio solutions, the metal in greater proportion was better adsorbed. Under all conditions, removal percentage was ∼60 %. The column could be reused throughout ten absorption/desorption cycles without significant alterations in adsorption capacity.

Management of Cervical Cancer in Pregnant Women: A Multi-Center Retrospective Study in China.

Background: This retrospective multi-center study aimed to describe the epidemiological characteristics, clinical features, and management of patients with cervical cancer in pregnancy (CCIP) and evaluate maternal and infant outcomes.Methods: The data of patients with CCIP were retrospectively collected from those diagnosed and treated in 17 hospitals in 12 provinces in China between January 2009 and November 2017. The information retrieved included patients' age, clinical features of the tumor, medical management (during pregnancy or postpartum), obstetrical indicators (i.e., gestational age at diagnosis, delivery mode, and birth weight), and maternal and neonatal outcomes. Survival analyses were performed using Kaplan–Meier survival curves and log-rank tests that estimated the overall survival of patients.Results: One-hundred and five women diagnosed with CCIP (median age = 35 years) were identified from ~45,600 cervical cancer patients (0.23%) and 525,000 pregnant women (0.020%). The median gestational age at cancer diagnosis was 20.0 weeks. The clinical-stage of 93.3% of the patients with CCIP was IB1, 81.9% visited the clinic because of vaginal bleeding during pregnancy, and 72.4% had not been screened for cervical cancer in more than 5 years. To analyze cancer treatments during pregnancy, patients were grouped into two groups, termination of pregnancy (TOP, n = 67) and continuation of pregnancy (COP, n = 38). Analyses suggested that the TOP group was more likely to be diagnosed at an earlier gestational stage than the COP group (14.8 vs. 30.8 weeks, p < 0.001). The unadjusted hazard ratio for the COP group's overall survival was 1.063 times that of the TOP group (95% confidence interval = 0.24, 4.71). There were no significant differences between the TOP and COP groups in maternal survival (p = 0.964). Thirty-three of the infants of patients with CCIP were healthy at the end of the follow-up period, with a median age of 18 ± 2.8 months.Conclusions: Most patients with CCIP had not been screened for cervical cancer in over 5 years. The oncologic outcomes of the TOP and COP groups were similar. A platinum-based neoadjuvant chemotherapy regimen could be a favorable choice for the management of CCIP during the second and third trimesters of pregnancy.

Influence of Different Surface Pretreatments on Shear Bond Strength of an Adhesive Resin Cement to Various Zirconia Ceramics.

The aim of this in vitro study was to assess the influence of surface pretreatment on shear bond strength (SBS) of an adhesive resin cement (G-CEM Link Force TM, GC Corporation, Tokyo, Japan) to three different yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics: (1) Copran Zirconia Monolith HT, COP; (2) Katana ML Zirconia, KAT; and (3) Metoxit Z-CAD HTL Zirconia, MET. In total, 45 cylinders (5 mm in diameter, 1 mm height) for each type of zirconia ceramic were prepared used a computer-aided design and computer-aided manufacturing (CAD/CAM) machine (software CEREC 4.2). Each type of zirconia was subdivided into three groups and each group received a different surface pretreatment; 15 samples were not conditioned as control (groups COP 1, KAT 1, MET 1), 15 samples were air-borne particle abraded with aluminum dioxide particles of 50-μm size at 0.3 MPa for 20 s (groups COP 2, KAT 2, MET 2), and 15 samples were hot-etched with a solution of hydrochloric acid and ferric chloride (groups COP 3, KAT 3, MET 3). After specimen fabrication, the adhesive cement–ceramic interface was analyzed using an SBS test. Subsequently, the adhesive remnant index (ARI) was measured. Data were submitted to statistical analysis. Air-borne particle abraded specimens showed the highest SBS values for COP and KAT groups. For MET, no significant difference was reported between air-borne particle abraded specimens and untreated controls. The lowest values were detected for acid-etched groups. A higher frequency of ARI = “1” and ARI = “2” was reported in control and air-borne particle abraded groups, whereas ARI = “3” was detected in hot-etched groups. No correlation was found between ARI score and shear bond strength. Air-borne particle abrasion is considered the best treatment for Zirconia Copran and Zirconia Katana ML, if it is followed by using dual-curing resin cement.

Cessation of pacing in super-responders of cardiac resynchronization therapy: A randomized controlled trial.

The consequence of cessation of biventricular pacing in super-responders of cardiac resynchronization therapy (CRT) has not been fully investigated. In this prospective, single-blinded clinical trial, 21 super-responders were randomly assigned to the ceased pacing (CeP, 11 patients) group or the continued pacing (CoP, 10 patients) group. Patients randomized to the CeP group underwent cessation of biventricular pacing. New York Heart Association (NYHA) class, quality of life (QOL) assessed with Minnesota questionnaire, 6-minute walking distance (6MWD), left ventricular end systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and left ventricular ejection fraction (LVEF) were compared between groups at 3- and 6-month follow-up. No significant difference was observed between the CeP and CoP groups regarding NYHA class, QOL, 6MWD, LVESV, LVEDV, or LVEF after 3 months (all P > 0.05). After 6 months, there existed no significant difference between the CeP and CoP groups with regard to NYHA class, QOL, 6MWD, LVESV, and LVEDV (all P > 0.05); however, LVEF was significantly lower in the CeP group than that of the CoP group (0.49 ± 0.10 vs 0.60 ± 0.11, P = 0.04), and LVEF was significantly reduced in the CeP group compared with the baseline value at randomization (0.49 ± 0.10 vs 0.54 ± 0.06, P = 0.04). LVEF was significantly reduced in super-responders of CRT 6 months after cessation of pacing. Super-responders to CRT should receive continued, long-term pacing to preserve recovered LV function.

Effect of copulation on estrus duration, LH response, and ovulation in Boer goats

The objectives of this investigation were to determine the effect of copulation on estrus duration, LH response and ovulation in Boer goats. A controlled randomized study, with two replicates, in which does were divided at each replicate in treatment (COP; n = 12) and control (CON; n = 12) groups was performed. All the does were pluriparous and estrus synchronized with CIDR (progesterone 300 mg) maintained in the vagina for seven days, and received 50 μg of GnRH at device insertion and 5 mg of natural prostaglandin F-2α im at CIDR removal. The COP group received two copulas within the first 4 h of estrus onset, and the CON group was only permitted to be mounted. Estrus was detected twice a day during the first 24 h after pessary removal and then every 4 h by using bucks with canvas apron as teasers, led by leash for 96 h. Blood was collected during all the estrus period after each estrus detection and analyzed for LH by radioimmunoassay (RIA). In addition, at the second replicate ovulation time and number of ovulations were also monitored by transrectal ultrasonography using a linear 7.5 MHz probe beginning 24 h after estrus onset and repeated every 4 h until all the preovulatory follicles disappeared. Estrus onset was 36.7 ± 10.5 h and 35.5 ± 13.6 h for CON and COP groups, respectively (P = 0.82). Estrus duration for the same groups was 40.3 ± 9.9 h and 28.3 ± 4.7 h, respectively (P = 0.001). The LH peak time for the CON group was 17.7 ± 6.3 h, and for the COP group, it was 10.9 ± 2.6 h (P = 0.004). The LH peak magnitude for the same groups was 31.5 ± 16.2 ng/mL and 34.9 ± 20.7 ng/mL, respectively (P = 0.34). The LH peak duration was not different between groups (CON: 7.3 ± 1.6 h versus COP: 7.2 ± 2.4 h; P = 0.94). The first ovulation time for CON and COP groups was 33.7 ± 3.9 h and 29.1 ± 3.2 h (P = 0.05), and the last ovulation time for the same groups was 37.7 ± 3.9 h and 32.6 ± 2.5 h, respectively (P = 0.02). The overall time from LH peak to ovulation was 18.6 ± 4.8 h without differences between groups (CON: 16.3 ± 5.6 h versus COP: 20.6 ± 3.3 h; P = 0.15). The number of ovulations for the CON group was 2.2 ± 0.4, and for COP group, it was 2.1 ± 0.4 (P = 0.96). It was concluded that copulation reduced estrus duration and hastened LH peak and ovulation in Boer goats.

Examination of commercially available copper oxide wire particles in combination with albendazole for control of gastrointestinal nematodes in lambs

Control of gastrointestinal nematodes (GIN) remains a critical issue due to the prevalence of anthelmintic resistance. The objective of the experiment was to determine the efficacy of copper oxide wire particles (COWP) from three commercial sources and a combination of COWP and albendazole to control GIN and/or Haemonchus contortus in lambs. Naturally infected Katahdin lambs in early June 2014 and 2015 were randomly assigned to receive no COWP (CON; n=9 and 12) or 2g COWP in a gel capsule as Copasure® (COP; n=4 and 17; Animax Ltd.), copper oxide—wire form (AUS; n=7 in 2014 only; Pharmplex), Ultracruz™ (ULT; n=8 and 15; Santa Cruz Animal Health™), no COWP and albendazole (CON+alb; n=10 in 2015 only; 15mg/kg BW; Valbazen®; Zoetis Animal Health), or COWP+alb (n=7 and 11; in 2014, lambs were administered alb on day 3). Lambs grazed grass pastures as a group and were supplemented with 227g/lamb daily of a commercial grain mix (15% crude protein) and the same amount of alfalfa pellets. Feces were collected on days 0 (day of COWP treatment), 7, and 14 for determination of fecal egg counts (FEC). Pooled (2014) or pooled treatment group feces were cultured on days 0, 7, and 14 (2015 only) to determine GIN genera. Data were analyzed using repeated measures in a mixed model, and FEC were log transformed. The predominant GIN on day 0 was H. contortus (87%) in 2014, and there was a mixed population in 2015. The mean FEC was reduced by day 7 in AUS and ULT lambs (treatment×day, P=0.001), and all of the COWP products were similar. By day 14, the AUS FEC were lower than the CON and COP groups. When examining the combination of COWP and synthetic anthelmintic, the FEC of COWP+alb were reduced to nearly 0eggs/g (back-transformed) and lower than the other groups (treatment×day, P=0.001). The percentage of H. contortus in cultured feces was reduced to a greater extent in the COWP than CON or CON+alb groups of lambs. In a mixed GIN population, the COWP products appeared to be similar in efficacy and using a combination of COWP+alb increased the efficacy not only against H. contortus, but all GIN genera present, offering options in the face of resistance to benzimidazoles.

Olive Oil, Flaxseed Oil 및 Perilla Oil을 급여한 Mice의 지질대사에 미치는 목초액의 영향

Abstract Our objectives in this experiment were to study the effects of oils that are high in contents of unsaturated fatty acids (olive, flaxseed, and perilla oils) and pyroligneous liquor on plasma lipid concentrations in mice. Male ICR-mouse (n=10 per group) were fed powdered form diets containing oil and pyroligneous liquor for 60 days. The cholesterol level of the PP group (96.71±25.75 ㎎/㎗) was lower than that of the COW group (133.56±21.53 ㎎/㎗). Levels of triglyceride of COP, CFP, and CPP groups were 121.10±50.79 ㎎/㎗, 77.80±38.58 ㎎/㎗, and 92.40±33.04 ㎎/㎗, respectively (p<0.05). The dietary addition of olive oil increased the plasma lsevels of cholesterol and LDL-cholesterol. On the other hand, the dietary addition of flaxseed oil and pyroligneous liquor increased the plasma level of HDL-cholesterol and decreased the plasma levels of LDL-cholesterol and triglyceride compared with those of the control group. Further, the dietary addition of perilla oil decreased plasma triglyceride but increased HDL-cholesterol. The decrease in the cholesterol level was much higher in the CFP group. In conclusion, the dietary addition of long-term pyroligneous liquor effectively decreased the plasma levels of cholesterol and triglyceride and increased the plasma level of HDL-cholesterol. The additional dietary administration of flaxseed and perilla oils increased the effect of pyroligneous liquor.Key words: pyroligneous liquor, flaxseed oil, perilla oil, cholesterol, triglyceride

Abstract 337: Plasma Oncotic Pressure Is Reduced in Transfused Trauma Patients

Objective: Hemorrhagic shock is the leading cause of potentially preventable traumatic death. Many of these deaths are believed to be avoidable with appropriate resuscitation. We investigated the role of initial plasma colloid osmotic presure (COP, i.e. oncotic pressure) on outcomes in trauma patients. Methods: Plasma samples were collected from 10 healthy consented volunteers and 27 patients (TRPs) upon admission to the emergency department (ED). Biophysical properties of plasma including osmolality, COP, and serum protein were measured and correlated to clinical data. Initial vital signs, routine laboratory values, type and volume of resuscitative fluids were recorded 24 hours post-ED admission as was length of hospital stay. Results: COP was significantly reduced in TRPs compared to controls 17.7±2.6 vs 20.7±2.1 mmHg (p&lt;0.05). COP strongly correlated (R 2 =0.8) to serum protein values, 6.1±0.8 in TRPs compared to controls, 6.6±0.4 g/dL. COP in TRPs were further categorized into Low (L&lt;15.3 mmHg, N=7), Moderate (M=15.3-19.3 mmHg, N=13) and Normal COP (N&gt;19.3 mmHg, N=6) subgroups, based on the interquartile range. TRPs with low and moderate COP had similar heart rates, systolic and diastolic blood pressures (128/75 mmHg, HR=94); whereas TRPs with N COP had higher blood pressures (148/93 mmHg). TRPs with L COP also received more blood transfusions within the first 24 hours of admission (L=1340±1568 ml, M=131±316 ml, and N=0 ml). Crystalloid infusions during the first 24 hours were similar among all groups (L=1480±1051 ml, M=1130±1040 ml, N=1171±965 ml). TRPs with L COP had longer hospital stays than M and N COP groups (13.5 vs. 7 days). Conclusions: Reduced COP and protein levels in TRPs are indicative of injury and hemorrhage. TRPs with low COP were more likely to receive blood transfusions during the first 24 hours and had longer hospital stays despite having similar vital signs as the M and N COP groups. In the absence of significant alterations in blood pressures and heart rate, COP and protein levels were indicative of a requirement for blood transfusions. We believe that using COP and protein levels in conjunction with current protocols could potentially improve resuscitation strategies for trauma patients.

Studio clinico sull’efficacia del polishing nelle sedute di mantenimento

Objectives Scaling and polishing are commonly used to maintain periodontal health. The aim of this study was to evaluate the efficacy of different instruments for this purpose 3 months after treatment. Materials and methods The study included 49 participants. The following parameters were evaluated before (T0) and 3 months after (T3) treatment: clinical attachment level (CAL), percentage of sites with plaque (full-mouth plaque score, FMPS), and percentage of sites with bleeding (full-mouth bleeding score, FMBS). All subjects received instructions for maintaining good oral hygiene. In 9 subjects dental polishing was not done (controls, cc group). Twenty-five subjects were treated with dental polishing using a professional polishing cup ( cop) (n = 13) or a professional polishing brush ( spaz) (n = 12). Statistical analysis t-test and ANOVA. Results and conclusions At T3, the FMPS was decreased in all groups. The FMBS showed no change in the cc group, whereas mean reductions of 3.18 and 5.38 were observed in the cop and spaz groups, respectively. Analysis of the CAL showed losses in the cc (0.46) and spaz (0.19) groups and a gain of 0.57 in the cop group. Further studies are needed.

Use of communities of practice in business and health care sectors: A systematic review

BackgroundSince being identified as a concept for understanding knowledge sharing, management, and creation, communities of practice (CoPs) have become increasingly popular within the health sector. The CoP concept has been used in the business sector for over 20 years, but the use of CoPs in the health sector has been limited in comparison.ObjectivesFirst, we examined how CoPs were defined and used in these two sectors. Second, we evaluated the evidence of effectiveness on the health sector CoPs for improving the uptake of best practices and mentoring new practitioners.MethodsWe conducted a search of electronic databases in the business, health, and education sectors, and a hand search of key journals for primary studies on CoP groups. Our research synthesis for the first objective focused on three areas: the authors' interpretations of the CoP concept, the key characteristics of CoP groups, and the common elements of CoP groups. To examine the evidence on the effectiveness of CoPs in the health sector, we identified articles that evaluated CoPs for improving health professional performance, health care organizational performance, professional mentoring, and/or patient outcome; and used experimental, quasi-experimental, or observational designs.ResultsThe structure of CoP groups varied greatly, ranging from voluntary informal networks to work-supported formal education sessions, and from apprentice training to multidisciplinary, multi-site project teams. Four characteristics were identified from CoP groups: social interaction among members, knowledge sharing, knowledge creation, and identity building; however, these were not consistently present in all CoPs. There was also a lack of clarity in the responsibilities of CoP facilitators and how power dynamics should be handled within a CoP group. We did not find any paper in the health sector that met the eligibility criteria for the quantitative analysis, and so the effectiveness of CoP in this sector remained unclear.ConclusionThere is no dominant trend in how the CoP concept is operationalized in the business and health sectors; hence, it is challenging to define the parameters of CoP groups. This may be one of the reasons for the lack of studies on the effectiveness of CoPs in the health sector. In order to improve the usefulness of the CoP concept in the development of groups and teams, further research will be needed to clarify the extent to which the four characteristics of CoPs are present in the mature and emergent groups, the expectations of facilitators and other participants, and the power relationship within CoPs.

Evolution of Wenger's concept of community of practice

BackgroundIn the experience of health professionals, it appears that interacting with peers in the workplace fosters learning and information sharing. Informal groups and networks present good opportunities for information exchange. Communities of practice (CoPs), which have been described by Wenger and others as a type of informal learning organization, have received increasing attention in the health care sector; however, the lack of uniform operating definitions of CoPs has resulted in considerable variation in the structure and function of these groups, making it difficult to evaluate their effectiveness.ObjectiveTo critique the evolution of the CoP concept as based on the germinal work by Wenger and colleagues published between 1991 and 2002.DiscussionCoP was originally developed to provide a template for examining the learning that happens among practitioners in a social environment, but over the years there have been important divergences in the focus of the concept. Lave and Wenger's earliest publication (1991) centred on the interactions between novices and experts, and the process by which newcomers create a professional identity. In the 1998 book, the focus had shifted to personal growth and the trajectory of individuals' participation within a group (i.e., peripheral versus core participation). The focus then changed again in 2002 when CoP was applied as a managerial tool for improving an organization's competitiveness.SummaryThe different interpretations of CoP make it challenging to apply the concept or to take full advantage of the benefits that CoP groups may offer. The tension between satisfying individuals' needs for personal growth and empowerment versus an organization's bottom line is perhaps the most contentious of the issues that make CoPs difficult to cultivate. Since CoP is still an evolving concept, we recommend focusing on optimizing specific characteristics of the concept, such as support for members interacting with each other, sharing knowledge, and building a sense of belonging within networks/teams/groups. Interventions that facilitate relationship building among members and that promote knowledge exchange may be useful for optimizing the function of these groups.

Assessment of head wear more than ten years after total hip arthroplasty: 22-mm zirconia vs. metal heads.

The present retrospective study assessed radiographs to determine socket wear in total hip arthroplasty (THA) with 22-mm zirconia or COP (Cobalt-Chrome alloy rich in Cobalt and Phosphorous) heads, and in cemented stems at more than 10 years after operation. Sockets of ultra high molecular weight polyethylene were used in each of two THA groups (13 hips each) in a clinical trial in our hospital between 1989 and 1990. Three observers carried out masked assessments of the radiographs. Upon final examination, there was no remarkable loosening in the zirconia or COP group, and no case had required revision surgery as of 2005. There was a statistically significant difference between the 2 groups in average annual linear wear, at 0.093 mm/year and 0.046 mm/year in the zirconia and COP groups, respectively. Volume wear and average annual volume wear were also significantly greater in the zirconia group despite its superior mechanical strength and toughness in vitro. Our present findings do not confirm early expectations of lower wear in long-term results of 22-mm zirconia femoral heads used in THA.

Evaluation of the method of treating non-Hodgkin's lymphoma

Forty-two patients with non-Hodgkin's lymphoma were treated between October 1983 and December 1992 in the department of Otolaryngology, Kagawa Medical School Hospital. The twenty-six of these patients whose tumor originated in Waldeyer's ring and who were diagnosed as Stage I or II have been reviewed. In principle, method of treatment was a combination of chemotherapy and radiotherapy. Between 1983 to 1987, COP was primarily used (9 cases) as combination chemotherapy, and after 1988 CHOP was used (17 cases). VAMA was used to treat the poor response and recurring cases. The five-year estimated overall survival rates calculated by the Kaplan-Meier method were 33.3% and 94.1% in the COP and CHOP groups, respectively. We investigated age, stage, cell type and grade, as factors related to recovery, but except for cell type, there were no significant differences in overall survival. The most serious side effect was decreased leucocyte count, but we prescribed G-CSF and were able to continue treatment.

Genetic analysis of bovine papillomavirus type 1 trans-acting replication factors.

The establishment of bovine papillomavirus type 1 in somatic mammalian cells is mediated by extrachromosomal replication and stable maintenance of the viral genome as a multicopy nuclear plasmid. Previous studies indicated the requirement of viral gene expression for bovine papillomavirus type 1 replication and plasmid maintenance (M. Lusky and M. R. Botchan, Cell 36:391-401, 1984; Turek et al., Proc. Natl. Acad. Sci. U.S.A. 79:7914-7918, 1982). To define the viral genes which are necessary for this process, we constructed a series of specific mutations within the viral genome and assayed the resulting mutants for their ability to replicate extrachromosomally in mouse C127 cells. We report here that the bovine papillomavirus type 1 trans-acting replication factors were encoded by at least two distinct viral genes since the mutants fell into two complementation groups, rep and cop. Mutants (rep-) affecting the E1 open reading frame (ORF) failed to replicate bovine papillomavirus type 1 DNA extrachromosomally and would integrate into chromosomal DNA. We suggest that this gene product is one of the factors required to specifically preclude the integration event. Mutants (cop-) affecting the E7 ORF were maintained in the extrachromosomal state; however, the copy number of the mutant genomes was reduced 100-fold compared with that of wild-type DNA. Analysis of single-cell subclones showed that each cell contained the mutant genomes at a copy number of one to two, indicating that the cop- phenotype did not reflect a simple segregation defect. We propose that the gene defined by mutations in the E7 ORF played a crucial role in stably maintaining the copy number of the viral plasmid at high levels. Genomes with mutations in the cop and rep complementation groups, when cotransfected, rescued the wild-type phenotype, extrachromosomal replication with a high, stable copy number for both types of plasmids. Therefore, the gene products acted in trans, and the mutations were recessive to the wild-type functions. One specific rep- mutant showed a 30-fold-increased transformation efficiency when compared with that of the wild-type genome. In addition, morphological transformation mediated by the cop- mutants appeared to be unstable. These results imply that either or both of the replication functions played some role in regulating the expression of the viral transforming functions.