Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Exploring opportunities for collaboration between the corporate sector and the dental education community

The ultimate purpose of both dental industry and dental education is to improve the oral health of the public. This report provides background information on the different roles and objectives of the dental industry and dental education communities, the different operating environment of each sector and also areas of common interest where collaboration will be of mutual benefit. The report addresses five areas for potential collaboration between the dental industry and the dental education communities: 1. Contribution to joint activities. 2. Effectiveness and efficiency. 3. Workforce needs. 4. Middle- and low-income countries. 5. The future of International Federation of Dental Educators and Associations (IFDEA). The traditional areas of support and their limitations that have been provided by industry are outlined in the report and some new approaches for collaboration are considered. Industry-based research has been an important factor in developing new products and technologies and in promoting oral health. However there is a need to facilitate the introduction of these developments at an early stage in the education process. Industry has to operate in an efficient manner to remain competitive and maximise its returns and therefore survive. The academic sector operates in a different environment and under different governance structures; although some trends are noted towards adoption of greater efficiency and financial accountability similar to industry. Opportunities to jointly develop best business practices should be explored. Industry has responded well to the oral health needs of the public through the development of new products and technologies. The education community needs to respond in a similar way by examining different healthcare delivery models worldwide and developing programmes to train members of the dental team to cater for future needs and demands of communities in different regions of the world. The reputation of industry-based scientists and clinicians is high, and their role in contributing to the dental education process in practical ways needs to be explored and further developed. Closer relationships between industry scientists and faculty and students could assist industrys need and desire to develop new technologies for the broader dental care system. The corporate sector can play a key role in the future success of IFDEA by providing support and expertise in developing areas such as regional leadership institutes, a Global Faculty and Network and in collaborating in developing continuing education programmes as well as involvement in its governance. Thirteen recommendations are made in the report. These are considered to be important initial steps in developing the already strong relationship between the education and corporate sectors. Partnership and collaborating more effectively along the lines suggested should, almost certainly, generate mutually beneficial outcomes, whilst serving over the long term to elevate the publics oral health status on a global basis.

Personalized surveillance and prognostication of patients undergoing kidney cancer surgery: The 15-year UCLA experience

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Background: Renal cell carcinoma (RCC) is a heterogeneous disease with varying biology, clinical manifestations, and outcome. An evolving understanding of prognostic factors for patients is leading toward individualized surveillance as well as treatment. We reviewed our large single center experience trying to maximize prognostication and surveillance for each patient. Methods: The charts of 1,825 patients with renal masses from 1989–2006 were reviewed and 263 variables/patient were recorded. 1,492 underwent partial or radical nephrectomy with the final histology being RCC. Statistical analysis was performed via Cox regression and concordance models. This enabled us to investigate the Surveillance & Prognosis University of California Integrated Staging System (S&P-UISS), a 3-tiered group system for based on low (LR), intermediate (IR) and high risk (HR) categorization separately for both non-metastatic (NM) and metastatic (M) patients, and to compare its prognostic accuracy with the current TNM classification. Results: Of all patients analyzed 66% were male. A Fuhrman grade of 1, 2, 3 and 4 was assigned to 179 (12.3%), 675 (46.5%), 485 (33.4%), and 114 patients (7.8%), respectively. ECOG performance status was 0, 1, 2 and 3 in 768 (52.1%), 652 (44.3%), 51 (3.5%), and 2 (0.1%), respectively. The disease-specific survival (%) for NM LR (n=326, 22%), IR (n=464, 32%), and HR (n=121, 8%) patients was, respectively, 97, 81, 62 at 5 years; 92, 46, 41 at 10 years; 92, 45, 20 at 15 years. For M LR (n=78, 5%), IR (n=406, 28%) and HR (n=58, 4%) survival was 41, 18, 8 at 5 years; 31, 7, 0 at 10 years; and 31, 0, 0 at 15 years, respectively. Based on concordance statistics, S&P-UISS predicted disease-specific survival better than the 2002 TNM system. Conclusions: The S&P-UISS system is a highly reliable and reproducible predictor of mortality following surgical therapy for localized and metastatic RCC. Surveillance and personal treatments should be individualized for a particular patient based on risk group categorization following surgery for their primary tumor. Accurate prognostication allows personal tailoring for treatments as well as allocation into clinical trials.

No significant financial relationships to disclose.

Antibodies against human putamen in adolescents with anorexia nervosa

OBJECTIVE

To examine whether antiputamen antibodies are present in adolescents with anorexia nervosa (AN).

METHOD

Using enzyme-linked immunosorbent assay (ELISA) with an extract of human putamen as an antigen, sera samples obtained from 22 adolescents with active AN and from 22 healthy adolescents (control group) were assayed for antibodies to neuronal components

RESULTS

Mean optical density (OD) readings for serum antibodies against human putamen in adolescents with AN was significantly greater than the mean OD readings in the control group (0.492 +/- 0.086 vs. 0.275 +/- 0.028, p =.02). When serum positivity was defined as an OD level greater than 2 SD above the mean control group value (0.541), antiputamen antibodies were detected in the blood of 6 AN patients (27%) whereas they were detected in the blood of 1 patient (5%) in the control group (p <.05; Fisher's exact test).

DISCUSSION

The detection of antiputamen antibodies in adolescents with AN suggests an underlying immune process at the putamen level in some patients with this eating disorder.

Omega-3 polyunsaturated fatty acids in adolescents: knowledge and consumption

OBJECTIVE

To assess adolescents' knowledge about n-3 polyunsaturated fatty acids (PUFA) and their dietary intake of these important nutrients.

METHODS

A questionnaire consisting of 12 questions assessing the knowledge and intake of n-3 PUFA and of a 24-h dietary recall was administered to 1117 ninth-grade adolescents (52% girls and 48% boys) attending five public schools. The adolescents were subsequently provided with verbal and written information on the health benefits, requirements, and dietary sources of n-3 PUFA. Dietary recalls were analyzed for energy and n-3 PUFA intake. Descriptive statistics, Student's t-tests, Chi-square analysis, and multiple regression analysis were used to assess adolescents' knowledge about n-3 PUFA as well as to examine relationships of independent variables with n-3 PUFA intake.

RESULTS

Most adolescents (89%) believed that eating fish, a main source of very long chain (VLC) n-3 PUFA, is healthy and may prevent heart disease (59%), but only a few knew about n-3 PUFA's role in alleviating inflammation (29%) and its potential for cancer prevention (25%). Many were aware of marine sources of n-3 PUFA, such as salmon (67%), tuna (46%), mackerel (30%), and herring (26%), but only 36% knew about adequate intake of VLC n-3 PUFA. The main source of n-3 PUFA information was parents (58%), whereas only 21% of adolescents reported that their care providers had discussed health benefits of n-3 PUFA with them. About one-third of adolescents consumed fish at least once a week, and 29% consumed fish once a month. Dislike (22% of participants) and allergy (3%) were the main reasons for rarely (< or = 3 times/year; 18%) or never (17%) consuming fish. Only one adolescent reported daily consumption of a fish concentrate supplement. Daily consumption of linolenic acid was higher in boys (0.38 +/- 0.02 g) than in girls (0.31 +/- 0.01 g; p =.002). Total intake of n-3 PUFA represented only 30% of the presently available (Canadian) recommended daily allowance (CRDA) for 14- to 15-year-old boys (1.4 g/day) and 29% of the CRDA for 14- to 15-year-old girls (1.2 g/day).

CONCLUSIONS

Adolescents are aware of some of the health benefits of n-3 PUFA but lack concrete information about dietary requirements of n-3 PUFA and about n-3 PUFA content of various dietary sources.

Serotesting versus presumptive varicella vaccination of adolescents with a negative or uncertain history of chickenpox

OBJECTIVE

To review the current practice of adolescent health care providers when an adolescent reports a negative or uncertain history of chickenpox in order to provide information for future practice.

METHODS

Retrospective chart review of a sample of patients seen in a hospital-based adolescent primary care clinic between 1996 and 1999.

RESULTS

Among adolescents who reported a positive history of chickenpox (190 patients, aged 15 +/- 1 years), varicella occurred before age 5 years in 30%, between 5 and 10 years in 56%, and at older than age 10 years in 14% of the patients. When adolescents reported a negative or uncertain history of varicella (55 patients, aged 15 +/- 1 years), serotesting was ordered for the majority (73%) of cases, while only 16% were presumptively vaccinated with varicella vaccine. In six patients no intervention was noted in the charts, and these patients were contacted. In 80% of the patients who were serotested, varicella IgG titers of > or = 1:32 indicated a previous unnoticed infection and lifelong immunity to varicella. In only 20% of the patients sera were negative for varicella IgG titer, requiring varicella vaccination. There was no statistical difference between the number of siblings of patients with a positive serologic test (3 +/- 1) and the number of siblings of seronegative patients (2 +/- 1, p = 0.41). Seven of the eight seronegative patients consented to varicella vaccination and were vaccinated within 10 months of serotesting.

CONCLUSIONS

These data support the practice of serotesting for a previously unnoticed varicella infection rather than presumptive vaccination in the adolescent age group. A follow-up vaccination of seronegative adolescents should be scheduled as close to serotesting as possible.

Urinary leukotriene (LT) E(4) in adolescents with dysmenorrhea: a pilot study

In the present study we measured levels of urinary leukotriene (LT) E(4) as an index of LT production during the menstrual cycle in adolescents. Mean urinary LTE(4) levels in girls with dysmenorrhea was approximately threefold higher than normal laboratory values on Day 1 of the menstrual period and approximately twofold higher than normal laboratory values on Day 5 of the menstrual period. Compared with urinary LTE(4) levels in girls with eumenorrhea, urinary LTE(4) levels in girls with dysmenorrhea were higher on Day 1 [361 +/- 123 pg/mg creatinine vs. 122 +/- 37 pg/mg creatinine, p =.1; not significant (NS)] and on Day 5 (202 +/- 26 pg/mg creatinine vs. 117 +/- 26 pg/mg creatinine, p <.05) of the menstrual period, as well as on Day 10 (159 +/- 33 pg/mg creatinine vs. 88 +/- 21 pg/mg creatinine, p =.1; NS) of the menstrual cycle. Increased urinary excretion of leukotrienes, inflammatory mediators known to cause potent vasoconstriction and uterine contractions, in girls with dysmenorrhea in this pilot study, suggests that these mediators may be involved in generating dysmenorrhea symptoms in adolescents.

Mutations in the cardiac transcription factor NKX2.5 affect diverse cardiac developmental pathways

Heterozygous mutations in NKX2.5, a homeobox transcription factor, were reported to cause secundum atrial septal defects and result in atrioventricular (AV) conduction block during postnatal life. To further characterize the role of NKX2.5 in cardiac morphogenesis, we sought additional mutations in groups of probands with cardiac anomalies and first-degree AV block, idiopathic AV block, or tetralogy of Fallot. We identified 7 novel mutations by sequence analysis of the NKX2.5-coding region in 26 individuals. Associated phenotypes included AV block, which was the primary manifestation of cardiac disease in nearly a quarter of affected individuals, as well as atrial septal defect and ventricular septal defect. Ventricular septal defect was associated with tetralogy of Fallot or double-outlet right ventricle in 3 individuals. Ebstein's anomaly and other tricuspid valve abnormalities were also present. Mutations in human NKX2.5 cause a variety of cardiac anomalies and may account for a clinically significant portion of tetralogy of Fallot and idiopathic AV block. The coinheritance of NKX2.5 mutations with various congenital heart defects suggests that this transcription factor contributes to diverse cardiac developmental pathways.

Linked insurance-tumor registry database for health services research

OBJECTIVE

Breast cancer screening and treatment data are often limited to restricted populations, including women older than 65 years old. The goal of this project was to develop procedures to link tumor registry and insurance claims databases on women younger than 65 years old with breast cancer and to assess the accuracy and validity of the linked dataset.

METHODS

Iowa Cancer Registry (ICR) and Wellmark Blue Cross/Blue Shield of Iowa (BC/BS) membership files of women with incident in situ or invasive breast cancer from 1989 to 1996 were linked. An automated deterministic match was followed with visual inspection from three independent reviewers applying a matching protocol. Matched and overall registry data were compared to assess population representativeness. Claims from BC/BS for incident cases during 1994 were examined for coding of a recent breast cancer diagnosis or treatment.

RESULTS

The final dataset included 4,397 matched cases of patients aged 21 years and older from 1989 to 1996. The sociodemographic and tumor characteristics of the ICR population younger than 65 years old (n = 7,469) with breast cancer or carcinoma in situ were nearly identical with those of the matched patients younger than 65 years old (n = 3,449). Nearly all (96%) of the 445 matched incident cases in 1994 had claims data (CPT, DRG, or ICD-9 code) indicative of breast cancer. Treatment patterns varied by data source, with agreement ranging from 76% to 82%.

CONCLUSIONS

The validity and generalizability of these data demonstrate their potential for further health services research among younger insured women with breast cancer. Additionally, the process outlined may be useful for developing other datasets to study other cancers in the population younger than 65 years old.

Effects of exercise training and its cessation on components of the insulin resistance syndrome in obese children

OBJECTIVE

To determine the effect of exercise training (ET) on components of the insulin resistance syndrome (IRS) in obese children.

DESIGN

Randomized, modified cross-over study, with subjects assigned to one of two conditions: (1) 4 months of ET followed by 4 months of no-ET; or (2) 4 months of no-ET followed by 4 months of ET. Measurements were made at three time points: 0, 4 and 8 months.

SUBJECTS

79 obese, but otherwise healthy children (age: 7-11 y, percent fat (%fat) 27-61%).

MEASUREMENTS

Plasma lipid and lipoprotein concentrations, plasma insulin and glucose concentrations; %fat; submaximal heart rate (HR) as an index of fitness. EXERCISE TRAINING: ET was offered 5 d/week 40 min/d. For the 73 children who completed 4 months of ET, the mean attendance was 80% (that is, 4 d/week) and the average HR during ET was 157 bpm.

RESULTS

Significant (P < 0.05) group x time interactions were found for plasma triglyceride (TG) and insulin concentrations and %fat. The average change for both groups, from just before ET to just after the 4 month ET was -0.24 mmol.l-1 for TG, -25.4 pmol.l-1 for insulin and -1.6 units for %fat. When Group 1 ceased ET, over the following 4 month period the average change for insulin was +26.6 pmol.l-1 and for %fat +1.3 units.

CONCLUSION

Some components (plasma TG, insulin, %fat) of the IRS are improved as a result of 4 months of ET in obese children. However, the benefits of ET are lost when obese children become less active.

Correlates of individual differences in body-composition changes resulting from physical training in obese children

BACKGROUND

No studies have been reported in children that assess correlates of body-composition changes in response to a physical training intervention.

OBJECTIVE

The hypothesis studied was that variation in diet and physical activity would explain a significant portion of the interindividual variation in the response of body composition to physical training.

DESIGN

The participants were 71 obese children aged 7-11 y (22 boys, 49 girls; 31 whites, 40 blacks). Body composition was measured by dual-energy X-ray absorptiometry, physical activity by a 7-d recall interview, and diet by two, 2-d recalls. The children underwent 4 mo of physical training.

RESULTS

The mean attendance was 4 d/wk, the mean (+/-SD) heart rate for the 40-min sessions was 157 +/- 7 beats/min, and the mean energy expenditure was 946 +/- 201 kJ/session. On average, the percentage body fat decreased significantly in the total group, and total mass, fat-free soft tissue, bone mineral content, and bone mineral density increased, but there was a good deal of individual variability. Multiple regression models indicated that in general, more frequent attendance, being a boy, lower energy intake, and more vigorous activity were associated with healthier body-composition changes with physical training. Ethnicity was not retained as a correlate of the change of any component of body composition.

CONCLUSIONS

In obese children, age, vigorous activity, diet, and baseline percentage body fat together accounted for 25% of the variance in the change in percentage body fat with physical training.

Effect of physical training and its cessation on percent fat and bone density of children with obesity

OBJECTIVE

We determined the effect of 4-month periods of physical training (PT) and detraining on percent fat (percent fat) and bone density of children with obesity.

RESEARCH METHODS AND PROCEDURES

Subjects were 79 7- to 11-year-old children with obesity; 34 were white, 44 were black, and 1 was Asian, 26 were male and 53 were female. They were randomly assigned to two groups: group 1 engaged in PT for the first 4 months, while group 2 engaged in PT during the second 4 months. Body composition was measured with dual energy absorptiometry, and diet was measured with 4 days of recall for each 4-month period. PT was offered 5 days/week for 40 minutes/session, heart rate monitors were worn, and no dietary information was given; mean attendance was 80%, and mean heart rate per session was 157 bpm.

RESULTS

Group by time interactions across the three time-points (from analysis of variance) were significant for percent fat (p = <0.001) and bone density (p = 0.045). Both groups declined in percent fat during the periods of PT, by an average of 1.6% fat units; in the 4 months after cessation of PT, group 1 increased by 1.3% fat. In both groups, bone density increased more during periods of PT (0.025 g/cm2) than during periods of no PT (0.010 g/cm2). No significant PT vs. no-PT differences were found for dietary intake of energy, macronutrients, or calcium.

DISCUSSION

This study suggests that regular exercise, without dietary intervention, can enhance the body composition of children with obesity.

Effect of physical training on total and visceral fat in obese children

PURPOSE

Children with high levels of total body fat mass (TFM) and visceral adipose tissue (VAT) have elevated levels of certain risk factors for coronary artery disease and non-insulin-dependent diabetes mellitus. We tested the hypothesis that controlled physical training, without dietary intervention, would have a favorable impact on VAT and percent body fat (%BF) in obese children.

METHODS

A volunteer sample of 74 obese children, 7-11 yr of age, accepted random assignment to physical training or control groups. Before and after 4 months of intervention, measurements were obtained for VAT, TFM, %BF, daily physical activity, and cardiovascular fitness. The intervention involved 4 months of controlled physical training 5 d x wk(-1), 40 min per session, at a mean heart rate (HR) of 157 beats x min(-1). The estimated energy expenditure (EE) per training session was 925+/-201 kJ.

RESULTS

Compared with the control group, the physical training group declined significantly in %BF (delta = -2.2%) (P < 0.01), TFM (delta = -3.1%) (P < 0.01), and subcutaneous abdominal adipose tissue (delta = - 16.1%) (P < 0.05), and increased significantly in fat-free mass (delta = +6.1%) (P < 0.05) and moderate-to-very hard physical activity (delta = +14.1%) (P < 0.05). The increase in VAT was significantly less in the physical training group (delta = +0.5%) as compared with that in the control group (delta = +8.1%) (P < 0.05).

CONCLUSIONS

This study showed that during physical training obese children: 1) were capable of participating in a substantial amount of high intensity physical training over a 4-month period: 2) accumulated significantly less VAT as compared with nonexercising controls; and 3) experienced other beneficial changes in total and regional body composition.

Prediction of visceral adipose tissue from simple anthropometric measurements in youths with obesity

OBJECTIVE

Although visceral adipose tissue (VAT) is the component of body composition most highly associated with cardiovascular risk factors, its measurement requires expensive procedures, such as magnetic resonance imaging. This study examined the ability of simple demographic and anthropometric measurements to predict magnetic resonance imaging-derived VAT in 76 apparently healthy, black and white youths with obesity who were 7 years to 16 years of age.

RESEARCH METHODS AND PROCEDURES

Stepwise multiple linear regression was used to develop a prediction equation for VAT based on 13 simple anthropometric variables (height, weight, body mass index, triceps skinfold, calf skinfold, sagittal diameter, waist circumference, hip circumference, thigh circumference, waist/hip ratio, waist/thigh ratio, sagittal diameter/thigh ratio, and percent body fat from the sum of calf and triceps skinfolds) and three demographic variables (age, gender and ethnicity).

RESULTS

The stepwise multiple regression procedure yielded a final model that included two anthropometric variables (sagittal diameter and waist/hip ratio) and one demographic variable (ethnicity). The prediction equation was: VAT = - 124.06+ 16.67 (ethnicity)+4.15 (sagittal diameter)+100.89 (waist/hip ratio), where ethnicity was coded as 0= black and 1 = white. The model explained 63% of the variance in VAT and was associated with a measurement error of 23.9%.

DISCUSSION

Although the model seems to lack sufficient explanatory power for routine use in clinical settings with individual patients, it may have some utility in epidemiological studies given its relatively small (<25%) standard error of estimate.

Adolescents and calcium: what they do and do not know and how much they consume

PURPOSE

To assess knowledge about calcium and dietary intake among a sample of adolescents.

METHODS

A survey consisting of 24-h dietary recall and 14 questions assessing knowledge about calcium was administered to 1117 adolescents (52% girls and 48% boys) attending the ninth grade in five public schools.

RESULTS

A majority (98%) believed that dietary calcium is healthy, strengthens the bones (92%), and may prevent osteoporosis (51%), but only a few were aware of the role of calcium in neuromuscular function (20%) and blood pressure regulation (15%). About 60% knew that adolescence is a critical period for peak bone mass accretion. Only 19% were aware of the recommended dietary allowance (RDA) of calcium for adolescents [4 servings (1200 mg)/day]. The majority knew that dairy products are the main dietary source of calcium, but only 10% were aware of the calcium content of various dairy products. Only 45% knew about nondairy sources of calcium. The adolescents' main sources of calcium information were health teachers (55%) and parents (46%), while only 38% reported that their health care providers had discussed health benefits of calcium. Dairy products accounted for most of the reported daily calcium intake, and the majority (79%) reported consuming dairy products daily. "Dislike" and allergy were the main reasons given for not consuming dairy products. One third reported daily supplementation with vitamins and minerals, 68% of which contained 100-200 mg of elemental calcium. Calculated calcium intake (foods, beverages, and supplements) was 536 +/- 19 mg/24 h (45% of RDA) in girls and 681 +/- 28 mg/24 h (57% of RDA) in boys (p < 0.0001).

CONCLUSIONS

While adolescents are aware of the main health benefits of calcium, they lack specific information about daily requirements and calcium content of the various dietary sources. This lack of information may contribute to adolescents' suboptimal intake of calcium.

On the need to screen for Chlamydia and gonorrhea infections prior to colposcopy in adolescents

PURPOSE

The purposes of this study were to explore the association of pelvic inflammatory disease (PID) with cervical biopsy and to examine whether screening for Chlamydia and gonorrhea infections within 2 weeks prior to colposcopy is a standard clinical practice among adolescents' care providers in the United States.

METHODS

An anonymous questionnaire was distributed to U.S. physicians and nurses who are members of the Society for Adolescent Medicine, and/or the North American Society for Pediatric and Adolescent Gynecology.

RESULTS

A total of 368, from all the states in America, responded. Only 5% of the respondents have encountered biopsy-associated PID owing to Chlamydia and/or gonorrhea. The incidence rate of biopsy-associated PID reported by the respondents to this survey was approximately 1:1000 colposcopic biopsies. Fifteen percent of the respondents screen their adolescent patients, and 23% favor screening for Chlamydia and gonorrhea infections within 2 weeks prior to colposcopy. Previous experience with colposcopy and previous encounters with biopsy-associated PID in adolescents did not significantly affect the practice or the opinion of the respondents.

CONCLUSIONS

Screening for Chlamydia and gonorrhea infections within 2 weeks prior to colposcopy in adolescents is presently not a common clinical practice among U.S. adolescents' care providers. Because of the potential risk of biopsy-associated PID, it is advisable to minimize the interval between Chlamydia and gonorrhea screening and colposcopy in adolescents.

Effect of physical training on heart-period variability in obese children

OBJECTIVE

The beat-to-beat variability in electrocardiogram intervals (RR, i.e., heart-period variability) provides information on cardiac autonomic activity that predicts arrhythmias and mortality rate in animals and adults. We determined the effect of physical training on heart-period variability in obese children.

METHODS

Thirty-five subjects were randomly assigned to physical training and control groups. The training involved 4 months of exercise, 5 days per week, 40 minutes per day. Cardiovascular fitness was measured with submaximal heart rate during supine cycling; percentage of body fat was measured with dual-energy absorptiometry; and resting heart-period variability parameters were measured in a supine position. A pretraining to posttraining change score was computed for each variable. The effect of the training was determined by comparing the changes of the training and control groups.

RESULTS

Compared with the control group, the trained group (1) reduced submaximal heart rate and percentage of body fat (p < 0.01); (2) increased in the root mean square of successive differences, a time-domain parameter reflective of vagal tone (p < 0.05); (3) decreased in low-frequency power expressed as a percentage of total power, a frequency-domain index of combined sympathetic and vagal activity (p < 0.03); and (4) decreased in the ratio of low- to high-frequency power, an index of sympathetic-parasympathetic balance (p < 0.01).

CONCLUSIONS

In obese children, physical training alters cardiac autonomic function favorably by reducing the ratio of sympathetic to parasympathetic activity.

Predicting maltreatment of children of teenage mothers

OBJECTIVE

To determine the degree to which knowing certain characteristics about young high-risk families can help distinguish those families most likely to maltreat their children from those families at lower risk of maltreating their children.

DESIGN

Observational cohort from which the following predictor variables were gathered when infants were 2 months old: maternal age, depressive symptoms, childrearing attitudes, social support, and living situation (with or apart from related adults). Families were followed up for 24 months to identify the occurrence of maltreatment.

SETTING

An urban, socioeconomically disadvantaged cohort of teenage mothers and their infants attending a hospital-based special primary care clinic for teen mothers and their infants.

PARTICIPANTS

All full-term infants and mothers enrolled into the clinic in 1990 participated in the study. This included 47 mother-infant pairs enrolled when infants were 2 months of age. Forty-five of these pairs were available for follow-up when infants were 24 months of age.

MAIN OUTCOME MEASURES

Maltreatment defined as any incident that prompted investigation by the state child protective agency and was found to be a substantiated case of maltreatment by that agency.

RESULTS

Maltreatment occurred in 15 of 45 families before the child's second birthday. Discriminate function analysis produced a model that correctly classified 13 of 15 maltreating mothers and misclassified one of 30 non-maltreating mothers. Stepwise analysis revealed that living situation was by far the strongest predictive variable (R2 = 7).

CONCLUSION

Maltreatment was a predictable outcome within this extremely high-risk cohort. Living apart from related adults was the strongest risk factor associated with maltreatment. This easily obtainable piece of information may be an important risk marker for practitioners, social service personnel, and others working with this very-high-risk population. It may allow early supportive interventions that might prevent maltreatment.

"High-tech" home care for children with chronic health conditions: a pilot study

The purposes of this study were to pilot test the instrument and methods for a major study of caregivers of children who are technology dependent and to test constructs proposed for the major study in a discrete sample. The major study will be implemented in 13 cities in the United States. The pilot was conducted in three small- to moderate-size metropolitan areas in the Southeast and Midwest. Seventy-three primary caregivers provided data during a structured telephone interviews. The children represented four groups of children dependent on technology as defined by the Office of Technology Assessment (OTA) (1987). The findings supported the methodology and the viability of the instrument. Analysis suggests that caring for a child who is technology dependent affects family functioning and increases family stress levels in some families. The financial burden is also significant. It is suggested that nurses can be a critical source of support and information to these families.

Adolescent risk-takers: a trauma center study of suicide attempters and drivers

Adolescence is a developmental stage characterized by excessive risk-taking behavior that produces adverse health effects, typically in the form of injury. At issue is whether adolescent suicide attempters and injured adolescent motor vehicle drivers constitute a common risk group and are differentiated by the response of the emergency medical care system and by case disposition. Data originated in the medical records of a Rhode Island (USA) trauma center. The two study groups were not distinguished by religious preference, socioeconomic status or timing of the injury incident, but differed significantly by gender, race, emergency vehicle use, hospital admission rates, and seasonal injury patterns. Alcohol and drug involvement was examined, but serious data deficiencies were noted.

Comparison of anti-fetal colonic microvillus and anti-CEA antibodies in peroperative radioimmunolocalisation of colorectal cancer

Local recurrence of colorectal cancer may result from failure to assess accurately the extent of tumour at operation. It has been suggested that peroperative radioimmunolocalisation may improve this assessment. The degree to which this is possible has been studied using a hand-held gamma detecting probe and comparing two 125I-labelled monoclonal antibodies to colorectal tumours. The antibodies were to fetal colonic microvillus membrane (FM1D10) and to carcinoembryonic antigen (A5B7). Sixty-nine per cent (9/13) of the FM1D10 and 98% (43/44) of A5B7 labelled tumours took up significant amounts of antibody with a tumour to normal colon ratio of more than 1.5:1. The uptake was significantly better for A5B7 with a median tumour to normal colon ratio of 3.3 (1.1-13.8) compared to 1.85 (0.75-7.7) for FM1D10 (P less than 0.001). The tumour: colon ratio of both antibodies was independent of the serum CEA, Dukes' stage or the degree of histological differentiation. There was a linear correlation for tumour to normal colon ratios between the gamma detecting probe and the same tissue examined in a conventional well counter (correlation coefficient r = 0.78, P less than 0.001). Colorectal tumours demonstrate a rapid and reliable uptake of anti-CEA monoclonal antibody A5B7. This antibody can be detected with a peroperative gamma detecting probe and has the potential to improve the surgeon's appreciation of the extent of tumour and therefore may influence the surgery performed. Detailed clinical studies are now being carried out.

Health risk behaviors and attempted suicide in adolescents who report prior maltreatment

We hypothesized that high school students who experienced prior maltreatment would be more likely than their peers to report health risk behaviors and suicide attempts. Before the establishment of a high school-based clinic, an anonymous needs assessment survey was completed by 600 adolescents (grades 9 to 12). Sociodemographic information was obtained and questions were asked about physical and sexual abuse, health-related behaviors and habits, and suicide attempts. Thirteen percent of the adolescents had been maltreated: 5.2% reported prior physical abuse, 5.4% sexual abuse, and 2.7% both physical and sexual abuse. Multivariate statistical techniques were used to clarify how previous abuse was related to adolescent risk-taking behaviors and suicide. Students with a history of physical abuse were three times more likely than non-abused peers to drink alcohol and smoke cigarettes, almost twice as likely to use illicit drugs, six times more likely to self-induce vomiting, and five times more likely to attempt suicide. A student with a history of prior sexual abuse had a three and one-half times greater chance of being sexually active and was more than three times more likely to attempt suicide. These data on a nonclinical, nondeviant population of adolescents indicate that physical or sexual abuse in childhood may have a significant impact on adolescent health risk behaviors and suicide attempts.

Abnormal vaginal bleeding secondary to iron deficiency in a thirteen year old

Abnormal vaginal bleeding in perimenarchal females is usually attributed to immaturity of the hypothalmic/pituitary/gonadal axis (i.e., dysfunctional uterine bleeding). Iron deficiency as a cause for abnormal bleeding has been described, but is poorly understood. This case report describes a 13-year-old Hispanic female with iron deficiency anemia as a presumptive cause for two episodes of abnormal vaginal bleeding. Anemia may be a cause as well as an effect of menorrhagia in young teenagers. Work-up should include evaluation of tissue iron stores if other etiologies for abnormal bleeding are not found.

Adolescents' willingness to use a school-based clinic in view of expressed health concerns

A health needs assessment was developed to facilitate implementation of a comprehensive school-based adolescent clinic. Students were asked about their willingness to use a school-based clinic for certain health and emotional problems. Six hundred students in grades 9 through 12 completed anonymous self-administered questionnaires. Twenty-eight percent of respondents reported recently feeling depressed; 12% reported a prior suicide attempt. Twenty-five percent of students felt they were overweight. Of 56% who had experienced intercourse at least once, only one third had ever used birth control. Twenty-one percent smoked cigarettes and 27% marijuana, 24% used other drugs, and 38% used alcohol. Students who reported depression and past suicide attempts were significantly (p less than or equal to 0.001) more willing to use the clinic for counseling needs than students not so reporting. Those with perceived weight problems reported more willingness to use a school clinic for nutrition information than those who did not feel overweight. Currently sexually active students were also more willing (p less than or equal to 0.001) than nonsexually active students to use the clinic for sexuality information and sexually transmitted disease screens. Respondents who used drugs, alcohol, or cigarettes, however, were no more willing than nonsubstance-using peers to use clinic services for relevant health information.

MIME chemotherapy (methyl-GAG, ifosfamide, methotrexate, etoposide) as treatment for recurrent Hodgkin's disease

Forty-seven patients with Hodgkin's disease in relapse were treated with MIME combination chemotherapy (methyl-GAG, ifosfamide, methotrexate, etoposide). All patients had previously received nitrogen mustard, vincristine, prednisone, procarbazine (MOPP) or similar regimens and doxorubicin-containing combinations, and many had received extensive irradiation. Complete remission (CR) occurred in 23%, and was influenced by presence of extranodal disease, hemoglobin, lactic dehydrogenase (LDH), and number of prior relapses. Median survival for all patients was 50 weeks, and was affected adversely by the presence of extranodal disease and the number of prior relapses. Toxicity was significant, including infections (23%), neutropenic fever (34%), and hemorrhagic cystitis (23%), but was related in part to the extent of prior therapy. These results with this novel chemotherapy program in heavily pretreated patients suggest that MIME should be studied in less extensively treated patients and considered as a part of treatment programs for patients with Hodgkin's disease in first relapse.

Results of MIME salvage regimen for recurrent or refractory lymphoma

Based on encouraging results of two previous ifosfamide-VP-16 salvage combinations, methyl-gag was added to ifosfamide, methotrexate, and etoposide (VP-16). This combination is called MIME. A total of 208 patients with recurrent lymphoma were treated with this regimen. Response rates were 24% for complete remission and 36% for partial remission. The MIME regimen was more effective in patients who were treated after being off front-line therapy for longer than 6 months. However, responses were also seen in patients with disease clearly resistant to front-line therapy, suggesting that MIME was at least partially non-cross-resistant with front-line doxorubicin-containing regimens. The 15-month median relapse-free survival of complete responders and the 9-month overall median survival time for all patients treated were both similar to results from previous ifosfamide-VP-16 combination use. This regimen has been effective in the treatment of patients with recurrent or refractory lymphoma, but cannot be considered curative in the majority of cases.

Hypercalcemia, unusual bone lesions, and human T-cell leukemia-lymphoma virus in adult T-cell lymphoma

Extensive generalized and subperiosteal bone resorption was demonstrated in a patient with adult T-cell lymphoma and marked hypercalcemia of unclear pathogenesis. Antibody to the human T-cell leukemia-lymphoma virus (HTLV) was present in the serum of the patient, consistent with the recently reported association of adult T-cell lymphoma, hypercalcemia, and HTLV. The unique feature of this case was the presence of bone radiographic and pathologic findings consistent with hyperparathyroidism, in the absence of elevated parathormone levels. These findings contrast with the few previously reported cases of adult T-cell lymphoma with hypercalcemia, which showed lytic, sclerotic, or osteoporotic bone lesions. The authors suggest that the patient's malignant T-lymphocytes may have produced an osteoclast-activating-factor-like substance or a parathormone-like substance, which caused the striking bone changes. The exact role of HTLV in the pathogenesis of such cases remains to be determined.

High-dose cytosine arabinoside in non-Hodgkin's lymphoma

Thirty-two patients with refractory non-Hodgkin's lymphoma were treated with high-dose cytosine arabinoside (ara-C) given at 2 g/m2 IV over three hours every 12 hours for 4-8 g/m2/course repeated at three to four week intervals. There were eight partial responses (29%) and two minor responses among 28 evaluable patients. The median response duration was 10 weeks (range, 6-33 weeks). The median survival was significantly prolonged in responders compared to nonresponders (28 versus 15 weeks; p = 0.03). Two additional patients treated with 12 g/m2/course died of sepsis and myelosuppression. The dose-limiting toxicity was myelosuppression, which was more pronounced in patients with prior extensive radiation therapy and bone marrow involvement. In vivo measurements of intracellular concentrations of ara-CTP, the active metabolite of ara-C, showed significantly higher values in bone marrows with lymphomatous involvement compared to normal bone marrows (210 versus 95 microM; p = 0.05), probably indicating a preferential formation and retention of ara-CTP in malignant cells compared to normal hemopoietic cells. In addition, higher ara-CTP levels were found in bone marrows that had higher percentages of cells in S phase.