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Biomedical subjects

C C Baker

Publications and source records attributed to C C Baker.

At least 55 records · Page 3Linked to original sources
PubMed1995

A statewide, population-based time-series analysis of the increasing frequency of nonoperative management of abdominal solid organ injury.

UNLABELLED: Emergency operative intervention has been one of the cornerstones of the care of the injured patient. Over the past several years, nonoperative management has increasing been recommended for the care of selected blunt abdominal solid organ injuries. The purpose of this study was to utilize a large statewide, population-based data set to perform a time-series analysis of the practice of physicians caring for blunt solid organ injury of the abdomen. The study was designed to assess the changing frequency and the outcomes of operative and nonoperative treatments for blunt hepatic and splenic injuries. METHODS: Data were obtained from the state hospital discharge data base, which tracks information on all hospitalized patients from each of the 157 hospitals in the state of North Carolina. All trauma patients who had sustained injury to a solid abdominal organ (kidney, liver, or spleen) were selected for initial analysis. RESULTS: During the 5 years of the study, 210,256 trauma patients were admitted to the state's hospitals (42,051 +/- 7802 per year). The frequency of nonoperative interventions for hepatic and splenic injuries increased over the period studied. The frequency of nonoperative management of hepatic injuries increased from 55% in 1988 to 79% in 1992 in patients with hepatic injuries and from 34% to 46% in patients with splenic injuries. The rate of nonoperative management of hepatic injuries increased from 54% to 64% in nontrauma centers compared with an increase from 56% to 74% in trauma centers (p = 0.01). In patients with splenic injuries, the rate of nonoperative management increased from 35% to 44% in nontrauma centers compared with an increase from 33% to 49% in trauma centers (p < 0.05). The rate of nonoperative management was associated with the organ injury severity, ranging from 90% for minor injuries to 19%-40% for severe injuries. Finally, in an attempt to compare blood use in operatively and nonoperatively treated patients, the total charges for blood were compared in the two groups. When compared, based on organ injury severity, the total blood used, as measured by charges, was lower for nonoperatively treated patients. CONCLUSIONS: This large, statewide, population-based time-series analysis shows that the management of blunt injury of solid abdominal organs has changed over time. The incidence of nonoperative management for both hepatic and splenic injuries has increased. The study indicates that the rates of nonoperative management vary in relation to the severity of the organ injury. The rates increase in nonoperative management were greater in trauma centers than in nontrauma centers. These findings are consistent with the hypothesis that this newer approach to the care of blunt injury of solid abdominal organs is being led by the state's trauma centers.

Humans↗
PubMed1995

Field triage of trauma patients based upon the ability to follow commands: a study in 29,573 injured patients.

UNLABELLED: If a trauma system is to deliver "the right patient to the right hospital at the right time," a simple triage tool that can be used in the field to rapidly identify patients with a significant risk of morbidity and mortality is vital. OBJECTIVE: The purpose of this study was to evaluate the effectiveness of the Glasgow Coma Scale's Motor Response Component (GMR) in identifying such patients. METHODS: From patient records in a well established state trauma registry, the predictive power of the Glasgow Motor Score was compared with the predictive power of the Injury Severity Score (ISS), Trauma Score, and whole Glasgow Coma Scale Score (GCS), using discriminant analysis and logistic regression. RESULTS: Complete data were available for analysis for 29,573 patients. Nine percent died. The analyses demonstrated that the GMR was almost as good as the TS and better than the other scores in identifying patients at risk of dying. The highest discriminant accuracy was obtained by predicting that patients with a GMR of 6 would live and that all others (GMR 1-5) were at risk of dying. This means separating patients according to whether or not they follow simple commands. CONCLUSIONS: The study demonstrated the GMR to be a good predictor of mortality in injured patients. Patients at risk of dying can best be identified by separating patients into those who cannot follow simple commands (GMR 1-5) from all others. This rapid and simple assessment could be useful as a prehospital tool to identify patients at risk of dying. First responders and nonmedical personnel not skilled in the use of the Trauma Score can easily determine if victims are able to follow commands and potentially identify the patients who are likely to require urgent trauma center care.

Glasgow Coma Scale↗
PubMed1995

Differentiation-specific alternative splicing of bovine papillomavirus late mRNAs.

Activation of the late promoter (PL) of bovine papillomavirus type 1 (BPV-1) is dependent on the differentiation state of keratinocytes and occurs in the upper layers of the bovine fibropapilloma. In this study, we show by in situ hybridization that a differentiation-specific pattern of BPV-1 late RNA splicing is also seen in the fibropapilloma. RNAs containing the 7385/3605 and 3764/5609 splice junctions were confined to the granular cell layer. In contrast, RNAs containing the 7385/3225 splice junction were present in both the granular and spinous layers. The switch in splice site usage in the granular cell layer limits the expression of the mRNA encoding the major capsid protein to these most terminally differentiated cells. Thus, BPV-1 late mRNA expression is regulated at both transcriptional and posttranscriptional levels.

Alternative Splicing↗
PubMed1995

The human immunodeficiency virus type 1 Rev protein and the Rev-responsive element counteract the effect of an inhibitory 5' splice site in a 3' untranslated region.

A 5' splice site located in a 3' untranslated region (3'UTR) has been shown previously to inhibit gene expression. Natural examples of inhibitory 5' splice sites have been identified in the late 3'UTRs of papillomaviruses and are thought to inhibit viral late gene expression at early stages of the viral life cycle. In this study, we demonstrate that the interaction of the human immunodeficiency virus type 1 Rev protein with the Rev-responsive element (RRE) overcomes the inhibitory effects of a 5' splice site located within a 3'UTR. This was studied by using both a bovine papillomavirus type 1 L1 cDNA expression vector and a chloramphenicol acetyltransferase expression vector containing a 5' splice site in the 3'UTR. In both systems, coexpression of Rev enhanced cytoplasmic expression from vectors containing the RRE even when the RRE and the inhibitory 5' splice site were separated by up to 1,000 nucleotides. In addition, multiple copies of a 5' splice site in a 3'UTR were shown to act synergistically, and this effect could also be moderated by the interaction of Rev and the RRE. These studies provide additional evidence that at least one mechanism of Rev action is through interactions with the splicing machinery. We have previously shown that base pairing between the U1 small nuclear RNA and a 3'UTR 5' splice site is required for inhibition of gene expression. However, experiments by J. Kjems and P. A. Sharp (J. Virol. 67:4769-4776, 1993) have suggested that Rev acts on spliceosome assembly at a stage after binding of the U1 small nuclear ribonucleoprotein to the 5' splice site. This finding suggests that binding of additional small nuclear ribonucleoproteins, as well as other splicing factors, may be necessary for the inhibitory action of a 3'UTR 5' splice site. These data also suggest that expression of the papillomavirus late genes in terminally differentiated keratinocytes can be regulated by a viral or cellular Rev-like activity.

Base Sequence↗
PubMed1995

Acute pancreatitis. Surgical management.

In general, the best approach to pancreatitis is to recognize its presence early, resuscitate the patient aggressively, and employ nutritional and medical therapy to avoid complications. Nonetheless, either because of trauma or failure of medical therapy, some patients develop complications (e.g., hemorrhagic or necrotizing pancreatitis, abscess, pseudocyst, or fistula) that require operative intervention. Expert surgical judgment is required to decide which patients require surgery, when to operate, and what operation(s) to perform. Many of these patients require multiple surgical procedures and are critically ill, requiring careful attention to nutritional support, ventilatory management, and surveillance for sepsis. The care of these patients requires a multidisciplinary approach involving personnel in internal medicine, gastroenterology, radiology, surgery, anesthesiology, and nursing. Pancreatitis does not respect the boundaries of class, race, creed, gender, or traditional specialty interests; only by using a collegial approach, which shares expertise in a multidisciplinary fashion, is it possible to optimize patient care and salvage critically ill patients with this deadly disease.

Acute Disease↗
PubMed1994

Activation of Kupffer cells in vivo following femur fracture.

OBJECTIVE: To test the hypothesis that Kupffer cells are activated after blunt femur fracture leading to altered hepatic oxygen (O2) consumption. DESIGN: Prospective randomized experimental trials. SETTING: Laboratory. MATERIALS AND METHODS: Male Sprague-Dawley rats underwent closed femur fracture with associated soft-tissue injury. Control animals received only anesthesia. After 30 minutes and 2 hours, livers were perfused and fixed. Tissue was processed for scanning and transmission electron microscopy. In separate experiments, hepatic O2 consumption was measured in isolated perfused livers 2 and 48 hours after femur fracture using a Clark-type electrode. Oxygen consumption was calculated from the influent-effluent concentration difference, flow rate, and liver weight. RESULTS: In femur-fractured animals, scanning electron microscopy revealed alterations in Kupffer cell surface characteristics, including increases in cell volume and complex foldings and extensions of the plasma membrane. Transmission electron microscopy showed internal vacuolization and dark-staining granule formation. The changes were more pronounced 2 hours after femur fracture. Hepatic O2 consumption increased significantly at both 2 and 48 hours after femur fracture. Morphologic and functional activation of Kupffer cells were not seen in control animals. CONCLUSION: In vivo ultrastructural evidence shows Kupffer cell activation after closed femur fracture. This activation is associated with increased hepatic O2 consumption, which is present at 2 hours and persists 48 hours following injury. The results suggest that Kupffer cell activation may be related to the acute-phase response following trauma.

Animals↗
PubMed1994

A population-based study of the association of medical manpower with county trauma death rates in the United States.

OBJECTIVE: To determine the association between measures of medical manpower available to treat trauma patients and county trauma death rates in the United States. The primary hypothesis was that greater availability of medical manpower to treat trauma injury would be associated with lower trauma death rates. SUMMARY BACKGROUND DATA: When viewed from the standpoint of the number of productive years of life lost, trauma has a greater effect on health care and lost productivity in the United States than any disease. Allocation of health care manpower to treat injuries seems logical, but studies have not been done to determine its efficacy. The effect of medical manpower and hospital resource allocation on the outcome of injury in the United States has not been fully explored or adequately evaluated. METHODS: Data on trauma deaths in the United States were obtained from the National Center for Health Statistics. Data on the number of surgeons and emergency medicine physicians were obtained from the American Hospital Association and the American Medical Association. Data on physicians who have participated in the American College of Surgeons (ACS) Advanced Trauma Life Support Course (ATLS) were obtained from the ACS. Membership information for the American Association for Surgery of Trauma (AAST) was obtained from that organization. Demographic data were obtained from the United States Census Bureau. Multivariate stepwise linear regression and cluster analysis were used to model the county trauma death rates in the United States. The Statistical Analysis System (Cary, NC) for statistical analysis was used. RESULTS: Bivariate and multivariate analyses showed that a variety of medical manpower measures and demographic factors were associated with county trauma death rates in the United States. As in other studies, measures of low population density and high levels of poverty were found to be strongly associated with increased trauma death rates. After accounting for these variables, using multivariate analysis and cluster analysis, an increase in the following medical manpower measures were associated with decreased county trauma death rates: number of board-certified general surgeons, number of board-certified emergency medicine physicians, number of AAST members, and number of ATLS-trained physicians. CONCLUSIONS: This study confirms previous work that showed a strong relation among measures of poverty, rural setting, and increased county trauma death rates. It also found that counties with more board-certified surgeons per capita and with more surgeons with an increased interest (AAST membership) or increased training (ATLS) in trauma care have lower per-capita trauma death rates.(ABSTRACT TRUNCATED AT 400 WORDS)

Black or African American↗
PubMed1994

Clinical benefits of an immune-enhancing diet for early postinjury enteral feeding.

In this multicenter prospective controlled trial, 98 evaluable patients sustaining major torso trauma were randomized to receive early enteral nutrition with a new "immune-enhancing" diet (study: n = 51) or a standard stress enteral formula (control: n = 47). At baseline, both groups had comparable demographics and Injury Severity Scores. After 7 days of feeding, the groups had equivalent increases in serum total protein, albumin, and transferrin concentrations. Patients receiving the "immune-enhancing" diet, however, experienced significantly greater increases in total lymphocyte (p = 0.014), T lymphocyte (p = 0.04), and T-helper (p = 0.004) cell numbers. Additionally, these patients had significantly fewer intraabdominal abscesses (study, 0% vs. control, 11%; p = 0.023) and significantly less multiple organ failure (study, 0% vs. control, 11%; p = 0.023). In conclusion, this multicenter trial suggests this "immune-enhancing" enteral diet offers clinical benefits in stressed surgical patients.

Abdominal Injuries↗
PubMed1994

Effect of resuscitation with hydroxyethyl starch and lactated Ringers on macrophage activity after hemorrhagic shock and sepsis.

Hemorrhagic shock appears to predispose patients to subsequent sepsis. This study examined the effect of different resuscitation fluids on macrophage function following hemorrhagic shock. Male Sprague-Dawley rats were bled to a blood pressure of 50 mmHg for 60 min and then resuscitated with 6% hydroxyethyl starch (HES) or Lactated Ringers (LR). Phagocytic function was assessed by clearance of IV colloidal carbon (C). Carbon clearance was not statistically different between control (154.89), shock LR (169.16), and shock HES (144.60). Computerized image analysis of C distribution in sections of liver and spleen taken 4 h after C infusion exhibits a significant decrease in C distribution after resuscitation with HES compared to control and animals resuscitated with LR (Student's t test, p < .05). Male CBA/J mice were bled to a mean blood pressure of 50 mmHg for 60 min and then resuscitated with either LR (N = 18) or HES (N = 17). In separate experiments CBA/J mice had no shock, but were given LR or HES followed by cecal ligation and puncture and later excision (CLPE). A final group had shock with either LR or HES resuscitation and then CLPE as above. Splenocytes were harvested 48 h after shock for mixed lymphocyte culture (MLC). Animals undergoing shock with subsequent septic challenge (Shock/CLPE) showed significantly increased mortality 40 vs. 0% (chi square, p < .05) and immunosuppression on MLC 2,088(LR)/3,300 (HES) vs. 18,570 (LR)/17,705 (HES) compared to CLPE alone (Student's t test, P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Sequences homologous to 5' splice sites are required for the inhibitory activity of papillomavirus late 3' untranslated regions.

Expression of bovine papillomavirus type 1 (BPV-1) late genes is limited to terminally differentiated keratinocytes in an infected epithelium. We have previously shown that although the BPV-1 late polyadenylation site is functional in nonpermissive cells, a 53-nucleotide (nt) fragment of the late 3' untranslated region acts posttranscriptionally to reduce polyadenylated cytoplasmic RNA levels. This 53-nt fragment does not appear to function by destabilizing polyadenylated cytoplasmic RNA (P. A. Furth and C. C. Baker, J. Virol. 65:5806-5812, 1991). In this study, we used site-directed mutagenesis and deletion analysis to demonstrate that the sequence AAG/GUAAGU, which is identical to the consensus 5' splice site sequence, was both necessary and sufficient for the inhibitory activity of the 53-nt fragment. Furthermore, base pairing between the 5' end of the U1 small nuclear RNA and this 5' splice site-like sequence was shown to be required for the inhibitory activity in vivo. We have also further mapped the human papillomavirus type 16 late 3' inhibitory element (I. M. Kennedy, J. K. Haddow, and J. B. Clements, J. Virol. 65:2093-2097, 1991) to a 51-nt region containing four overlapping sequence motifs with partial homology to 5' splice sites. Mutation of each of these motifs demonstrated that only one of these motifs is required for the inhibitory activity. However, the presence of the other motifs may contribute to the full inhibitory activity of the element. No BPV-1 or human papillomavirus type 16 mRNAs which are spliced by using the potential 5' splice sites present in the viral late 3' untranslated regions have been identified. This suggests that the primary function of these 5' splice site-like sequences is the inhibition of late gene expression. The most likely mechanism of action of these elements is reduction of polyadenylation efficiency, perhaps through interference with 3'-terminal exon definition.

Base Sequence↗
PubMed1993

An analysis of the association of trauma centers with per capita hospitalizations and death rates from injury.

OBJECTIVE: This study used population-based data bases to assess the association of trauma centers with per capita county hospitalization and trauma death rates in the State of North Carolina. SUMMARY BACKGROUND DATA: The current study extended previous work using two North Carolina data bases to assess the association of the presence of a trauma center with per capita county trauma death rates. METHODS: Data on per capita county trauma hospitalizations and deaths were obtained from the state hospital discharge data base and the North Carolina Medical Examiner's data base. Bivariate and multivariate analysis techniques were used. The dependent variables of interest were prehospital, hospital, and total trauma death rates and hospitalization rates for injury. RESULTS: Bivariate analysis identified a number of factors associated with per capita county hospitalizations and trauma death rates. These included the per cent unemployment, racial distribution, county alcohol tax receipts, and advanced life support certified emergency medical services providers. The per capita trauma death rates were significantly lower in counties with trauma centers compared with those without trauma centers (4.0 +/- 0.5 and 5.0 +/- 1.1 deaths per 10,000 population, p = 0.0001, respectively). The per capita hospitalizations for trauma were also lower in counties with trauma centers. Multivariate modeling showed that the presence of a trauma center and advanced life support providers were the best predictors of decreased per capita county trauma death rates. CONCLUSIONS: The study showed that the presence of a trauma center and advanced life support training were the two medical system factors that were the best predictors of the per capita county prehospital and total trauma death rates. These findings are consistent with the hypothesis that trauma centers are associated with a decrease in trauma death rates.

Adolescent↗
PubMed1993

Differentiation-specific expression from the bovine papillomavirus type 1 P2443 and late promoters.

The papillomavirus life cycle is tightly linked with keratinocyte differentiation in squamous epithelia. Vegetative viral DNA replication begins in the spinous layer, while synthesis of capsid proteins and virus maturation is restricted to the most differentiated or granular layer of the epithelium. In this study, in situ hybridization of bovine fibropapillomas was used to demonstrate that the activity of two promoters of bovine papillomavirus type 1 (BPV-1) is regulated in a differentiation-specific manner. In situ hybridization with a late promoter (PL)-specific oligonucleotide probe suggested that PL is dramatically upregulated in the granular layer of the fibropapilloma. Northern (RNA) blot analysis of RNA from BPV-1-infected fibropapillomas indicated that the three major BPV-1 late-region mRNAs were transcribed from PL. These RNAs include the previously described L1 (major capsid) mRNA as well as two larger mRNAs. The two larger mRNAs were characterized and shown to contain the L2 (minor capsid protein) open reading frame as well as the L1 open reading frame. In contrast to PL, the P2443 promoter was maximally active in basal keratinocytes and the fibroma. The major mRNA transcribed from P2443 is the putative E5 oncoprotein mRNA which is spliced between nucleotides 2505 and 3225. No signal was detected above the basal layer with use of a probe specific for this mRNA. The E5 oncoprotein has previously been localized by immunoperoxidase staining to the granular cell layer as well as the basal cell layer of the fibropapilloma (S. Burnett, N. Jareborg, and D. DiMaio, Proc. Natl. Acad. Sci. USA 89:5665-5669, 1992). These data suggest that E5 proteins in the basal cell and granular cell layers are not translated from the same mRNA.

Animals↗
PubMed1992

Vascular injuries in a rural state: a review of 978 patients from a state trauma registry.

The demographics, etiology, and outcome of 1148 vascular injuries suffered by 978 patients reported from eight trauma centers in a largely rural state to a trauma registry (NCTR) data base containing 26,617 patients entered over a 39-month time interval were analyzed. Vascular injury patients were more frequently transferred by helicopter (18%), referred from other hospitals (45%), transfused more blood (8 units mean/24 hours), had higher mean ISS values (14 vs. 9), had lower systolic blood pressures on admission (113 vs. 128 mm Hg), had higher emergency department mortality (3.3%), and required immediate surgery more often (79%) when compared with nonvascular injury NCTR patients (p = 0.0001). Vascular injury patients had significantly longer hospital stays (13 vs. 10 days), longer ICU stays (5 vs. 4 days), and greater hospital costs ($22,500 vs. $12,300) while incurring more serious AIS values for the regions of the chest, abdomen, and extremities. One hundred twenty-nine (13.1%) died, 97 after admission compared with a 6.2% mortality for NCTR nonvascular injury victims. Forty-seven percent of vascular injuries were extremity lesions; the amputation rate was 1.3%; and management was most often by simple repair (41.9%) or patching (22.2%). Rural vascular injury patients had a high incidence of blunt trauma (43.4%) and were older (average, 51 years); they were transported by helicopter more often (30.3%) and were frequently referred from another hospital (77.8%); they had longer ICU, ventilator, and hospital stays and greater hospital charges; and they had higher mortality (14.2%) compared with urban vascular trauma victims. The data suggest a need for the trauma care system to focus on earlier recognition, stabilization, and rapid transportation of this most seriously injured group of patients.

Age Factors↗
PubMed1992

Prospective comparison of clinical judgment and APACHE II score in predicting the outcome in critically ill surgical patients.

Prospective identification of patients who will not survive has been proposed as a means of limiting utilization of medical resources including critical care. This study prospectively compared prediction of outcome for surgical ICU patients by clinical assessment and the APACHE II score. Five hundred seventy-eight patients were assessed within 24 hours of admission by the ICU attending physician and predicted to live or die. An APACHE II score was calculated in that same time period. All data were stored in a data base and compared with actual SICU outcome. There were 40 deaths in 578 patients (6.9%). The clinical assessment had an overall accuracy of 95.2% vs. 90.9% for APACHE II. The Pearson correlation coefficients for the two methods of prediction were 0.59 for clinical assessment and 0.44 for APACHE II. Predictive power was not greatly improved by combining both prediction methods. Over 40% of patients predicted to die by both methods actually survived. This study demonstrates that clinical assessment is superior to APACHE II in predicting outcome in this group of surgical patients, although the difference is small. In addition, this study suggests that neither clinical assessment nor the APACHE II score, when obtained within 24 hours of admission, is very reliable at predicting which surgical ICU patients will die.

Adolescent↗
PubMed1992

Multivariate population-based analysis of the association of county trauma centers with per capita county trauma death rates.

UNLABELLED: The purpose of this study was to utilize a large population-based data base to determine the association of trauma centers with per capita county trauma death rates. METHODS: Per capita county trauma death rate, the dependent variable in the model, was obtained from a well-validated state Medical Examiner's data base. Over 200 county demographic, prehospital, and hospital trauma care resource variables were obtained from a variety of sources for multivariate modeling. Bivariate analysis identified candidate variables for multivariate modeling, excluding highly correlated independent variables to avoid problems of collinearity. Multivariate linear regression, logistic regression, and stepwise discriminant analysis were used to determine the relative association of the candidate variables with per capita county trauma death rates. RESULTS: Bivariate analysis identified multiple factors associated with per capita county trauma death rates. These included, among others: county rurality, percentage of unemployment, percentage nonwhite, 911 access, and ALS certified EMS. Per capita trauma death rates were significantly lower in counties with trauma centers compared with counties without trauma centers (4.0 +/- 0.5 and 5.0 +/- 1.1 deaths per 10,000 population, p = 0.0001, respectively). Multivariate analysis demonstrated that the presence of a trauma center in the county and ALS were the best medical system factors predicting decreased per capita county trauma death rates. CONCLUSIONS: This study is unique in utilizing a regional population-based data base of all trauma deaths in a large state to analyze the association of trauma centers and trauma death rates. Multivariate modeling controlling for other county variables demonstrated that the presence of a trauma center and Advanced Life Support training were the best predictors of per capita county trauma death rates. These findings are consistent with the hypothesis that trauma centers decrease trauma death rates.

Adult↗
PubMed1992

Fracture-dislocation of the lumbosacral spine: case report and review of the literature.

This report describes an extensively comminuted fracture of the sacrum and the L-5 vertebral body with complete anterior dislocation of the lumbar spine on the sacrum that occurred in a 19-year-old man ejected from a motor vehicle. Lumbosacral dissociation was characterized by computed tomography with three-dimensional and multiplanar reconstruction, and definitively managed by posterior instrumentation using locking hook spinal rods attached to the pelvis with hockey stick attachments by the Galveston technique. Implications of this case and a review of the literature are presented.

Adult↗
PubMed1992

Transient replication of human papillomavirus DNAs.

Information on papillomavirus DNA replication has primarily derived from studies with bovine papillomavirus type 1 (BPV-1). Our knowledge of DNA replication of the human papillomaviruses (HPVs) is quite limited, in part because of the lack of a cell culture system capable of supporting the stable replication of HPV DNA. This study demonstrates that the full-length genomic DNAs of HPV types 11 and 18 (HPV-11 and HPV-18), but not HPV-16, are able to replicate transiently after transfection into several different human squamous cell carcinoma cell lines. This system was used to identify the viral cis and trans elements required for DNA replication. The viral origins of replication were localized to a region of the viral long control region. Like BPV-1, E1 and E2 were the only viral factors required in trans for the replication of plasmids containing the origin. Cotransfection of a plasmid expressing the E1 open reading frame (ORF) from HPV-11 with a plasmid that expresses the E2 ORF from HPV-6, HPV-11, HPV-16, or HPV-18 supported the replication of plasmid DNAs containing the origin regions of HPV-11, HPV-16, or HPV-18, indicating that there are functions shared among the corresponding E1 and E2 proteins and origins of these viruses. Although HPV-16 genomic DNA did not replicate by itself under experimental conditions that supported the replication of HPV-11 and HPV-18 genomic DNAs, expression of the HPV-16 early region functions from a strong heterologous promoter supported the replication of a cotransfected plasmid containing the HPV-16 origin of replication. This finding suggests that the inability of the HPV-16 genomic DNA to replicate transiently in the cell lines tested was most likely due to insufficient expression of the viral E1 and/or E2 genes required for DNA replication.

Base Sequence↗