Platelet-derived endothelial cell growth factor expression and angiogenesis in cervical intraepithelial neoplasia and squamous cell carcinoma of the cervix

Growth and metastatic spread of invasive carcinoma depends on angiogenesis, the formation of new blood vessels. Platelet-derived endothelial cell growth factor (PD-ECGF) is an angiogenic growth factor for a number of solid tumors, including lung, bladder, colorectal, and renal cell cancer. Cervical intraepithelial neoplasia (CIN) is the precursor to squamous cell cervical carcinoma (SCC). Mean vessel density (MVD) increases from normal cervical tissue, through low- and high-grade CIN to SCC. We evaluated PD-ECGF immunoreactivity and correlated its expression with MVD in normal, premalignant, and malignant cervical tissue. PD-ECGF expression was assessed visually within the epithelial tissues and scored on the extent and intensity of staining. MVD was calculated by counting the number of vessels positive for von Willebrand factor per unit area subtending normal or CIN epithelium or within tumor hotspots for SCC. Cytoplasmic and/or nuclear PD-ECGF immunoreactivity was seen in normal epithelium. PD-ECGF expression significantly increased with histologic grade from normal, through low- and high-grade CIN, to SCC (P < .02). A progressive significant increase in the microvessel density was also seen, ranging from a mean of 28 vessels for normal tissue to 57 for SCC (P < .0005). No correlation was found between PD-ECGF expression and MVD (P = .45). We conclude that PD-ECGF expression and MVD increase as the cervix transforms from a normal to a malignant phenotype. PD-ECGF is thymidine phosphorylase, a key enzyme in the activation of fluoropyrimidines, including 5-fluorouracil. Evaluation of PD-ECGF thymidine phosphorylase expression may be important in designing future chemotherapeutic trials in cervical cancer.

Dentists' participation in capitation and preferred provider organization dental plans

BACKGROUND

In 1998, the American Dental Association Survey Center conducted a telephone and mail survey of U.S dentists in private practice in an effort to determine the extent of dentists' participation in capitation and preferred provider organization, or PPO, dental plans and the characteristics of dentists who participate in those plans.

METHODS

An initial phone screening survey was conducted with a random sample of 11,550 dentists in private practice. Dentists who indicated that they participated in capitation or PPO dental plans received a follow-up mail survey asking specific questions concerning these two types of dental plans.

RESULTS

Almost one-half of responding dentists indicated that they participated in either capitation or PPO dental plans. However, far more dentists reported participating in PPO dental plans than in capitation dental plans. The majority of participating dentists' patients were reported to be fee-for-service patients.

CONCLUSIONS

Dentists' participation in PPO dental plans generally increased from that indicated in previous surveys, though participation in capitation plans declined. There was some regional and demographic variation in participation in these dental plans, but such differences were not large. Pricing and concerns about quality of care continue to be the primary concerns of nonparticipating dentists.

PRACTICE IMPLICATIONS

Dentists reporting participation in PPO dental plans are becoming more common, but such plans still do not cover the majority of participating dentists' patients. A large percentage of nonparticipating dentists cite pricing and concerns about quality care as reasons for not joining these plans.

Does histological incomplete excision of cervical intraepithelial neoplasia following large loop excision of transformation zone increase recurrence rates? A six year cytological follow up

OBJECTIVE

To determine the risk of recurrent cervical intraepithelial neoplasia (CIN) in women with complete or incomplete excision of cervical intraepithelial neoplasia treated by large loop excision of transformation zone (LLETZ).

DESIGN

A retrospective study

SETTING

One consultant-led colposcopy clinic at Leicester Royal Infirmary

POPULATION

Three hundred and ninety-four women referred consecutively to the colposcopy clinic between 1991 and 1992.

MAIN OUTCOME MEASURES

The histological recurrence rate of CIN, length of cytological follow up following treatment related to degree of completeness of excision at initial treatment.

RESULTS

Three hundred and twenty-two women had complete cytological or histological follow up. The mean length of follow up was 73 months with a mean number of six smears. Women with incomplete excision of CIN had a significantly higher risk of recurrent CIN (relative risk 8.23) occurring in a significantly shorter time compared with women with complete excision.

CONCLUSIONS

This study demonstrates that large loop excision of transformation zone is successful in over 95% of cases. Cytological surveillance is satisfactory for follow up of women who have complete excision of CIN. Women with incomplete excision of CIN at initial LLETZ remain at significant risk of developing further CIN and long term colposcopic and cytological follow up is necessary.

Trends in total caries experience: permanent and primary teeth

BACKGROUND

This article is the last in a series of three that focuses on recent changes in the caries status of children aged 18 years or younger in the United States.

METHODS

This study is based on analyses of data regarding total carious (treated and untreated) permanent and primary teeth among children 6 to 18 years old and children 2 to 10 years old from the first and third National Health and Nutrition Examination Surveys, or NHANES I and NHANES III. The NHANES is periodically conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention.

RESULTS

The cumulative number of carious permanent teeth, both treated and untreated, among 6- to 18-year-olds decreased 57.2 percent, from 4.44, as measured in NHANES I, to 1.90, as measured in NHANES III. The cumulative number of carious primary teeth, both treated and untreated, among 2- to 10-year-olds decreased 39.7 percent, from 2.29, as measured in NHANES I, to 1.38, as measured in NHANES III.

CONCLUSIONS

Since the 1970s, the cumulative number of carious permanent and primary teeth, both treated and untreated, has declined substantially among children in the United States.

PRACTICE IMPLICATIONS

Effective prevention has reduced caries in children. As a result, dental practice will be more focused on maintaining intact dentitions than on repairing teeth damaged by disease.

Trends in untreated caries in primary teeth of children 2 to 10 years old

BACKGROUND

This article is the second in a series of three that focus on recent changes in the caries status of children and adolescents in the United States.

METHODS

This study is based on analyses of data regarding untreated carious primary teeth among children 2 to 10 years of age from the first and third National Health and Nutrition Examination Surveys, or NHANES I and NHANES III. The NHANES is conducted periodically by the National Center for Health Statistics of the Centers for Disease Control and Prevention.

RESULTS

Overall, the number of carious primary teeth among children 2 to 10 years old decreased from 1.42 as measured in NHANES I to 0.63 as measured in NHANES III. The number of carious primary teeth in children 2 to 10 years old also decreased across four demographic variables: age, sex, race and poverty level.

CONCLUSIONS

The number of untreated carious primary teeth among children has declined. Since the 1970s, the absolute difference in untreated caries between disadvantaged children in the United States and the rest of the U.S. child population has narrowed, although not to the same extent as in permanent teeth.

PRACTICE IMPLICATIONS

On average, children of preschool and elementary-school age have less untreated caries than in the past. More often, dentists do not need to treat on a first visit. This provides more opportunity to introduce these children to preventive dentistry at an early age.

Trends in the dental health work force

BACKGROUND AND OVERVIEW

Using data from various American Dental Association projects (Distribution of Dentists Survey, the Survey of Dental Practice, the Dental Workforce Model, and the Survey of Predoctoral Dental Educational Institutions), the authors analyzed trends and projections for the dental work force. The article presents work-force projections overall and by sex, when available, through the first 20 years of the 21st century. The number of women practicing dentistry has been increasing rapidly, while the increase in the number of male dentists has been more modest. In the future, the number of female dentists is projected to increase while the number of male dentists is projected to decrease.

CONCLUSIONS

Estimates based on the ADA census data place the overall growth in the number of active private practitioners at 19.1 percent between 1982 and 1997. This growth signifies a substantial expansion of capacity to produce dental services in the United States. Growth will be slower in the future.

PRACTICE IMPLICATIONS

Changes in the dental work-force capacity and demographic distributions merit careful monitoring and analysis, because they no doubt will determine the dental profession's future ability to deliver needed dental services and influence practitioners level of busyness.

Trends in untreated caries in permanent teeth of children 6 to 18 years old

BACKGROUND

This article is the first in a series of three that focus on recent changes in the caries status of children and adolescents in the United States.

METHODS

This study is based on analyses of data regarding untreated carious permanent teeth among children 6 to 18 years of age from the first and third National Health and Nutrition Examination Surveys, or NHANES I and NHANES III. The NHANES is periodically conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention.

RESULTS

Overall, the number of carious permanent teeth among children 6 to 18 years old decreased from 1.43, as measured in NHANES I, to 0.33, as measured in NHANES III. The number of carious permanent teeth in children 6 to 18 years old also decreased across four demographic variables: age, sex, race and poverty level.

CONCLUSIONS

The number of untreated carious permanent teeth among children has declined dramatically. Since the 1970s, the absolute difference in untreated caries between disadvantaged children and the rest of the child population has narrowed substantially.

PRACTICE IMPLICATIONS

The reduction in untreated caries, the major oral disease among children, has been dramatic in all subgroups of children. This may reinforce the already apparent shift from restorative to preventive dental services.

Development of the Crash Injury Research and Engineering Network

The Crash Injury Research and Engineering Network has developed a computer database and wide area network for data sharing and analysis among 8 trauma centers. The computer database extends the National Highway Traffic Safety Administration's National Automotive Sampling System with medical- and trauma-related variables in a relational/object database system. The medical data include injury location details, injury subclassification systems, and medical images for better biomechanical injury evaluation. Key data elements are migrated to a core repository so that all centers can review the status of case acquisition across the network. Cases, whole or in part, may be migrated between centers so that individual center expertise may be shared in evaluating the cause of injury. Electronic rounds, where cases are reviewed simultaneously across multiple centers, are possible.

Cytomegalovirus is not associated with IgM anti-myelin-associated glycoprotein/sulphate-3-glucuronyl paragloboside antibody-associated neuropathy

Monoclonal antibodies reactive with the HNK-1 epitope of myelin-associated glycoprotein (MAG) and the sulphate-3-glucuronyl paragloboside (SGPG)-like glycolipids are often found in the serum of patients with IgM paraprotein-associated demyelinating neuropathy. The presence of such antibodies in patients with chronic polyneuropathy has recently been associated with evidence of active cytomegalovirus (CMV) infection by the polymerase chain reaction. We wished to test these findings and examined sera from patients with MAG-reactive or MAG-nonreactive paraproteinemic neuropathy and patients with paraproteinemia only for the presence of CMV DNA and anti-CMV antibodies. CMV DNA was not detected in sera from any patient group. Furthermore, anti-CMV antibody prevalence was normal and similar in all 3 groups. We therefore report no evidence of an association between CMV infection and anti-MAG/SGPG antibodies associated with paraproteinemic peripheral neuropathy.

Retirement savings of dentists in private practice

BACKGROUND

Retirement planning is an issue that concerns all working people. In this article, the authors present their analysis of the results of a 1995 American Dental Association survey that asked dentists questions about their plans to finance their retirement.

METHODS

The ADA's Survey Center conducts a periodic "Survey of Current Issues in Dentistry," which gauges dentists' opinions about a variety of topics of interest to dentistry. The authors analyzed the results of the 1995 survey in which retirement savings was one of the topics.

RESULTS

The majority of responding owner/dentists whose primary occupation was private practice (40.7 percent) indicated that they were relying only "a little" on the sales of their practices to finance their retirements. Overall, dentists whose primary occupation was private practice reported saving an average of 10.5 percent of their income specifically for retirement. The average total amount of money dentists invested in various retirement plans increased with age and was highest for the 55 to 59 and the 60 to 64 years of age cohorts. The only exception was the 401(k) plan, in which the peak occurred in the 65 years of age and older cohort.

CONCLUSIONS

Fifteen years ago most dentists retired between the ages of 60 and 69 years. Recent trends show that dentists are retiring at younger ages. This means that while in practice, dentists must save enough to support themselves for 20 or more years of retirement.

PRACTICE IMPLICATIONS

The transition from private practice to retirement can be difficult. Therefore, planning for the future is important. Dentists can benefit from making appropriate decisions based on age, investment goals, risk tolerance, monetary constraints and time until retirement.

Dental care utilization: how saturated is the patient market?

BACKGROUND

Dental care utilization is the percentage of the population who access dental services over a specified period. In this article, the authors report on the results of several dental care utilization studies.

METHODS

To date, dental utilization data have been gathered by large national studies via telephone interviews, face-to-face interviews or written surveys. In this article, the authors report on and compare dental care utilization rates provided by the Centers for Disease Control and Prevention, the National Center for Health Statistics, the Agency for Health Care Policy and Research and the American Dental Association.

RESULTS

As captured by the various studies, the percentage of people who indicated they visited a dentist within the past year increased gradually between 1983 and 1997. The authors found that dental care utilization rates are higher among women than they are among men, and they decrease with age and increase with income and educational level.

CONCLUSIONS

Although the available data vary, they suggest that more Americans are visiting a dentist. The demand for dental care is increasing overall, as well as across educational, racial and economic lines.

PRACTICE IMPLICATIONS

If, as recent studies suggest, approximately 75 percent of the population visits a dentist annually, there is only modest room for further expansion of dental care utilization. However, if dental care utilization rates are substantially lower as reported in older studies, then there is a greater potential for increased dental care utilization.

Trend analysis of dental practice rent and mortgage expenses: 1989-1995

BACKGROUND

The authors analyzed trends for rent and mortgage, as reported by independent active private practitioners, for the period of 1989-1995. Rent and mortgage were analyzed overall and by different characteristics.

METHODS

In the ADA's annual "Survey of Dental Practice," dentists reported gross billings and net incomes, as well as itemized practice expenses. The authors tabulated survey responses over time to develop trends and compare rent and mortgage expenses for each year. If trends over time were not exhibited, the authors combined multiple years of data to develop more reliable statistics.

RESULTS

Approximately three-fourths of independent active private practitioners reported rent but no mortgage expenses. The percentages of practitioners who reported rent or mortgage was stable over time. The percentage reporting rent only as an expense increased with the number of dentists in the practice, the age of the reporting dentist and the number of office locations. In contrast, the opposite was true for dentists reporting mortgage only as an expense.

CONCLUSIONS

The authors found that office rental is more common than is office ownership and that mortgages as a percentage of gross billings and in dollar amounts were similar to rents. They also found that because the cost of office space as a percentage of gross billings decreased as the number of dentists in the practice increased, limited economies of scale may be present in the cost of dental office space.

PRACTICE IMPLICATIONS

There is not a large financial advantage to ownership, so renting is likely to remain an important way to acquire office space. As only limited economies of scale exist in office space expenses, many group practices may choose to rent office space.

Borderline malignant change in recurrent müllerian papilloma of the vagina

Malignant change occurred in a benign, recurrent vaginal müllerian polyp. The patient, a 49 year old woman with cerebral palsy, presented with a polypoid mass in the vagina. At four years of age she had presented with a haemorrhagic polyp, and over the following years she had recurrent irregular bleeding and regrowth of the polypoidal mass, requiring a total of 10 operations to excise the polyp. Histological examination of the specimen showed typical müllerian features with tubal, endometrioid, and endocervical cell types. There were significantly abnormal nuclei, indicating low grade or borderline malignancy. Review of previous biopsies showed similar müllerian features but no atypia. This is the first reported case of borderline malignant change in a previously benign recurrent müllerian papilloma of the vagina. Definitive radical surgery or radiotherapy is contraindicated in this patient and she remains under follow up.

Trend analysis of dental expenditures by selected dentist and practice characteristics, 1985-1995

Using the reported gross billings from the annual ADA "Survey of Dental Practice," the authors estimated the total national dental expenditures according to various dentist characteristics for the period of 1985-1995. These selected characteristics are specialty, office time, number of dentists in the practice, sex, length of experience and U.S. region. As government agencies do not report dental expenditures by such dentist characteristics, the data presented in this article may be the first of their kind to be estimated and published.

EPR and CD spectroscopy of fast myosin light chain conformation during binding of trifluoperazine

The conformations of isolated rabbit fast myosin light chains (LCs) were modified using trifluoperazine (TFP), the hydrophobic calmodulin inhibitor. CD spectroscopy showed that TFP altered secondary structural content of the LCs, with half-maximal effects at TFP concentrations of approximately 14-50 microM, which is within the range required to alter muscle fiber contraction in both agonistic and antagonistic ways [Kurebayashi, N. & Ogawa, Y. (1988) J. Physiol. 403, 407-424]. EPR spectroscopy provided structural information from paramagnetic probes on C-terminal domain surfaces. In the absence of TFP, tauR (rotational correlation time) was 1.6 ns for both alkali light chains (ALCs) and 1.8 ns for light chain 2 (LC2). This was faster than expected for proteins of this size (approximately 10 ns). TFP progressively recruited the probes into populations with tauR sevenfold to 12-fold slower, with half-maximal effects at a TFP concentration of approximately 370-800 microM. The differences probably indicate that CD spectroscopy detects changes in protein conformation due to 'specific' TFP binding at the LC hydrophobic core, while less specific binding at higher TFP concentrations is required to effect conformational changes on the protein surfaces near the paramagnetic probes. TFP binding was generally not cooperative. Comparative sequence analysis between calmodulin, troponin C, and myosin LCs indicated considerable conservation between residues expected to bind TFP.

Dental expenditures by selected dentist and practice characteristics

Total estimated dental expenditures in 1995 were approximately $47.6 billion as reported by the Bureau of Economic Analysis, or BEA. According to the Health Care Financing Administration, or HCFA, the total estimated dental expenditures in 1995 were approximately $44.7 billion. Using the reported gross billings from the annual ADA "Survey of Dental Practice," the authors estimated that the total national dental expenditures in 1995 were about $45.5 billion. As this estimate falls between the BEA- and HCFA-estimated total dental expenditures, it is one confirmation of the reliability and validity of ADA's estimates. This estimate also can be used to look at dental expenditures by selected characteristics--such as specialty, office time and number of dentists in the practice.

Dental procedure fees 1975 through 1995: how much have they changed?

A shift toward diagnostic and preventive dentistry in the last two decades is evident from the change in the number of dental procedures performed, as well as the change in the percentage of time spent performing different types of procedures. During the period 1975 through 1995, the average nominal fees for selected dental procedures increased. Once inflation was taken into account, however, the increase in the average real fees charged was more modest.

Solo general practitioners and specialists

A solo practitioner is the sole owner of and the only dentist in a dental practice and also is the most common type of dental practitioner in the United States. The authors provide a brief look at solo general practitioners' and specialists' characteristics, including employment status, number of employees, time spent in the office, number of patient visits per week, gross billings, net income and practice expenses.

Net income, gross billings and practice expenses of independent dentists

One way to measure the vitality of a profession is to look at the trend in its practitioners' real incomes. During the 10-year period 1986 through 1995, the average real net income of all independent dentists rose 30.7 percent, or 2.7 percent annually, after being adjusted for inflation using 1995 U.S. dollars. The national per capita personal income (base = 1995) increased 10.1 percent during this same period, or about 1.0 percent annually [corrected]. Using real per capita income as a benchmark, the authors found that the purchasing power of dentists as a group has increased more rapidly than the purchasing power of the overall U.S. population.