Observation of multiple magnetorotons in the fractional quantum Hall effect

Magnetorotons in the dispersions of collective gap excitation modes of fractional quantum Hall liquids are measured in resonant inelastic light scattering experiments. Two deep magnetoroton minima are observed at nu = 2/5, while a single deep minimum is resolved at nu = 1/3. The observations are the first evidence of multiple roton minima in gap excitations of the quantum liquids. The results support Chern-Simons and composite fermion calculations that predict multiple roton minima for states with nu>1/3.

Safety of 2 recombinant human immunodeficiency virus type 1 (HIV-1) envelope vaccines in neonates born to HIV-1-infected women

To determine the safety of 2 candidate vaccines against human immunodeficiency virus type 1 (HIV-1), a randomized, placebo-controlled, multicenter trial compared low, medium, and high doses of the vaccines or an adjuvant among infants born to HIV-infected women. No local or systemic reactions of grade 2 or greater were reported 48 h after the subjects underwent immunization. Grade 3 or 4 chemistry toxicities occurred in 5 (3%) and grade 3 or 4 hematologic toxicities in 17 (11%) of 154 vaccinated subjects (not significantly different from 29 adjuvant recipients). CD4(+) cell percentages of < or = 20% occurred at least once in 9 vaccinated subjects and 1 control subject. Sustained CD4(+) cell percentages of < or = 20% occurred in 4 HIV-infected children. Fourteen infants (8%) were confirmed to be HIV-infected; median CD4(+) cell counts among these children were 2074, 1674, 1584, and 821 cells/mm(3) at birth and weeks 24, 52, and 104, respectively. Thus, both vaccines were safe and well tolerated in neonates, and there was no evidence of accelerated immunologic decline in HIV-infected infants.

The effects of regular source of care and health need on medical care use among rural adolescents

OBJECTIVE

To examine those factors associated with the use of different types of ambulatory health services in a rural adolescent population.

METHODS

The student bodies of 2 middle schools and 2 high schools in rural areas in a mid Atlantic state (N = 1615) were surveyed using a self-administered health status and health services use instrument. Logistic regression was used to assess factors predicting receipt of (1) preventive services, (2) problem-focused services, and (3) emergency services.

RESULTS

One third of the rural youth reported having received preventive services within the previous 3 months; 41% received problem-focused care, and 18% received emergency services. Having the same provider for both preventive and illness care was the most consistent and significant predictor of receipt for all types of ambulatory services. Of special note is the greater use of emergency services when subjects did not have a consistent provider for both preventive and illness care. Health need variables, measured across a wide range of domains, were additionally predictive, and their significance varied according to the type of services received.

CONCLUSIONS

This study provides compelling evidence that for rural adolescents, having a regular source of care and medical need are the most important predictors of use across a variety of types of ambulatory care.

Differential changes in neuropeptide Y and nicotinamide adenine dinucleotide phosphate-diaphorase-positive neurons in rat hippocampus after kainic acid-induced seizure

Changes in neuropeptide Y (NPY) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d)-positive neurons in the hippocampus were investigated 5, 10 and 20 days after kainic acid (KA) administration using a double labeling method. The numbers of NADPH-d-positive-only and NPY/NADPH-d-positive neurons decreased in the CA1/2-CA3 regions of the hippocampus, 5, 10 and 20 days after KA administration, however, the number of NPY-positive-only neurons increased in the same regions 5 and 10 days after KA administration. In the dentate gyrus (DG) region of the hippocampus, the numbers of NPY-positive-only, NADPH-d-positive-only and NPY/NADPH-d-positive neurons increased 5 days after KA administration, and 20 days after KA administration, the number of NADPH-d-positive-only neurons decreased to levels similar to or lower than the level of the controls. However, the numbers of NPY/NADPH-d-positive and NPY-positive-only neurons in the DG region 20 days after KA administration remained at control levels. These results indicate that, NADPH-d-positive-only neurons are vulnerable to, and NPY-positive-only neurons are resistant to KA-induced seizures in the whole hippocampus, but that NPY/NADPH-d-positive neurons have different sensitivities in subregions of the hippocampus to KA-induced seizures. In addition, the present findings provide the first statistical and morphological evidence, which demonstrates that NPY-positive-only, NADPH-d-positive-only and NPY/NADPH-d-positive neurons in the hippocampus have different sensitivities to KA-induced seizures.

Noncovalent thrombin inhibitors incorporating an imidazolylethynyl P1

A series of noncovalent tripeptidic thrombin inhibitors incorporating a unidazolylethynyl moiety at P1 was investigated. A number of compounds of this series were highly potent and selective versus trypsin, and several compounds demonstrated good oral absorption in rats (F = 58% for compound 19).

Role of MAP kinases p42erk-2/p44erk-1 in cementum-derived attachment-protein-mediated cell attachment

Cementum-derived attachment protein (CAP) is a collagenous protein which promotes the attachment and spreading of periodontal cell types. We examined the role of the MEK/MAPK pathway in CAP-mediated fibroblast attachment. Human gingival fibroblasts were labeled with 35S-methionine, and the effect of MAP kinase pathway inhibitor PD98059 on attachment and spreading on CAP-coated dishes was examined. Effect on cell proliferation on CAP-coated plates was determined by [3H]-thymidine uptake. Attachment of human gingival fibroblasts to CAP-containing surfaces activated extracellular-signal-regulated kinases (ERK) ERK-2 and ERK-1. In the absence of serum, the ERKs were activated 15 min after attachment, reaching peak levels after 3 hours, and the activity was sustained for at least 12 hours. The enzyme levels were inhibited in cells treated with PD98059. The PD98059 did not significantly affect the kinetics of fibroblast attachment or the number of cells attaching to CAP-coated plates. However, cell spreading was retarded. DNA synthesis as indicated by [3H]-thymidine uptake was not significantly affected. In contrast to PD98059, attachment, spreading, and [3H]-thymidine uptake were inhibited by the protein tyrosine kinase inhibitor genestein. Our results indicate that the MEK/MAPK pathway participates in CAP-mediated fibroblast spreading, but cell attachment and proliferation do not appear to require ERK-2.

[Precipitation of chlorella virus FJ-1 by polyethylene glycol(PEG8000)]

Chlorella virus FJ-1 was isolated in Fujian Province of China. It can be precipitated by polyethylene glycol(PEG8000) and the best condition if 7% PEG8000 and 4% NaCl. But the precipitation efficiency of PEG8000 is lower than that of ultracentrifugation.

Effect of high or low frequency electroacupuncture on the cellular activity of catecholaminergic neurons in the brain stem

Although the opioid system plays a pivotal role in the analgesic effect of electroacupuncture (EA), it has been suggested that other peptidergic systems also may be involved in the therapeutic effect of EA. Among several peptides for EA-induced analgesia, catecholamine (CA) is associated with the descending pain inhibitory system. We evaluated whether the different frequencies of EA modified the cellular activity of central CA synthesizing neurons using double labeling immunohistochemistry between Fos-like immunoreactive (FLI) neurons and dopamine-beta-hydroxylase (DBH)/tyrosine hydroxylase (TH)-positive neurons. We observed that different frequencies of EA increased the number of FLI neurons in catecholaminergic neurons, such as the dorsal raphe (DR), hypothalamic arcuate nucleus (Arc), locus coeruleus (LC), A5 noradrenaline cells (A5), and A7 noradrenaline cells (A7). In addition, different frequencies of EA significantly increased the ratio of colocalization between FLI neurons and TH positive neurons in DR, LC and Arc. Only low frequency EA increased the neuronal activity in Arc. The ratio of double labeling between FLI and DBH positive neurons was also elevated at both LC and A5. These data demonstrate that different frequencies of EA increase the cellular activity of central CA synthesizing neurons, suggesting that the CA system plays an important role in EA-induced analgesia.

Prevalence of tuberculosis infection among homeless young people in central and eastern Sydney

OBJECTIVE

To determine the prevalence of tuberculosis (TB) infection among homeless young people (aged 12-25 years) in central and eastern Sydney.

METHODOLOGY

A cross-sectional survey was conducted in 16 youth refuges and four drop-in centres in Central and Eastern Sydney Health Areas and at the Cellblock Youth Health Centre, Glebe and the Kirketon Road Centre, Darlinghurst, New South Wales (NSW). Participants completed a questionnaire and underwent Mantoux testing.

RESULTS

One hundred and forty-one young people completed questionnaires and 139 received a Mantoux test; 112 (80. 6%) had their Mantoux read and 10 (8.9%) were Mantoux positive (95% confidence interval 3.6-14.2). None of the risk factors examined were found to be associated with increased risk for TB infection.

CONCLUSIONS

In this sample of homeless young people in central and eastern Sydney, the Mantoux positivity rate appears to be higher than the general population in NSW, but they would not currently be considered a high-risk group for TB infection.

[The regulation activity of Chlorella virus gene 5' upstream sequence in Escherichia coli and eucaryotic alage]

The 5' upstream regions of adenine methyltransgerase gene and major coat protein gene (PAMT, PVP54) in Chlorella virus genomes were used to contract transformation vectors in E. coli and eukaryotic algae. The regulation activities of PAMT and PVP54 comparing with PRPL and CaMV35S promoters were analyzed in different E. coli strains and Chlorella species. It is found that the luciferase activity controlled by PAMT is 50-400 times higher than that controlled by PRPL. The regulation activity of PAMT in 2 Chlorella species is obviously higher than that of CaMV35S promoter. It is the first report that the 5' upstream region of Chlorella virus gene has strong regulation activity in eucaryotic algae. The result suggests this regulation sequence will have an excellent application in the eucaryotic algae genetic engineering.

Identification of an optimal Ncx binding sequence required for transcriptional activation

The Ncx gene encodes a homeobox containing transcription factor that belongs to the Hox11 gene family. We determined specific Ncx protein binding consensus DNA sequences. Optimal Ncx binding sequences were 5'-CGGTAATTGG-3' (TAAT core) and 5'-CGGTAAGTGG-3' (TAAG core), which coincided with the Hox11 binding sequence. Both Ncx and Hox11 could bind to the TAAT and the TAAG core oligonucleotide in vitro. However, they could efficiently transactivate the reporter plasmid linked to the TAAT core sequence but not to the TAAG core sequence. Thus, Ncx and Hox11 act as transcriptional activators via their target sequence, 5'-CGGTAATTGG-3'.

Image-guided percutaneous drainage of thoracic empyema: can sonography predict the outcome?

The aim of this study was to assess the safety and efficacy of image-guided percutaneous catheter drainage (IGPCD) of thoracic empyemas, and to correlate the outcome of IGPCD with the pre-procedural sonographic appearance. One hundred three patients (74 males and 29 females) with thoracic empyema (age range 1 month to 70 years, median age 28 years) underwent IGPCD. In 63 (61.17%) patients, IGPCD was the primary treatment modality; in 40 (38.84%) patients it was used after unsuccessful intercostal chest tube drainage (ICTD). Ultrasound was the main modality used for guidance; CT guidance was used in only 7 patients (6.8%). Eight- to 12-F pigtail catheters or 10- to 14-F Malecot catheters were used. The outcome was correlated with the pre-procedural US appearance (anechoic, complex non-septated or complex septated) of the empyema. The IGPCD technique was successful in 80 of 102 patients. Based on the US appearance, IGPCD was successful in 12 of 13 (92.3%) patients with anechoic empyemas; 53 of 65 (81.54%) patients with complex non-septated empyemas, and in 15 of 24 (62.5%) patients with complex septated empyemas. A statistically significant difference (p < 0.01) was seen in the outcome of IGPCD in the three categories. Twenty-two patients required further treatment: ICTD (n = 9; 2 of them later also underwent surgery); and surgery (n = 15). The duration of catheter drainage ranged from 2-60 days. No major complications were encountered. Percutaneous catheter drainage of thoracic empyemas with imaging guidance ensures accurate catheter placement with a high success and a low complication rate. Pre-procedural US can predict the likelihood of success of IGPCD.

Lymphoproliferative responses to recombinant HIV-1 envelope antigens in neonates and infants receiving gp120 vaccines. AIDS Clinical Trial Group 230 Collaborators

Children of mothers infected with human immunodeficiency virus type 1 (HIV-1) were immunized at birth and at 1, 3, and 5 months with 1 of 3 doses of recombinant gp120 vaccines prepared from SF-2 or MN strains of HIV-1. A total of 126 children were not infected; 21 received adjuvant only. Vaccine recipients developed lymphoproliferative responses on >/=2 occasions, responding more often to homologous HIV-1 antigens than did adjuvant recipients (56% vs. 14%; P<.001). Responses were appreciated after 2 immunizations and were maintained for >84 weeks after the last immunization. An accelerated immunization schedule (birth, 2 weeks, 2 months, and 5 months) with the lowest dose of the SF-2 vaccine produced responses in all 11 vaccinees by 4 weeks. Responses to heterologous envelope antigens were also detected. Immune responses to vaccination are achievable at an age when some infection (perinatal or breast milk exposure related) may be prevented.

Use of human immunodeficiency virus (HIV) human hyperimmune immunoglobulin in HIV type 1-infected children (Pediatric AIDS clinical trials group protocol 273)

The clinical, immunologic, and virologic effects and the pharmacokinetics of human immunodeficiency virus (HIV) human hyperimmune immunoglobulin (HIVIG) were assessed in 30 HIV-infected children aged 2-11 years. All had moderately advanced disease with an immune complex-dissociated (ICD) p24 antigen >70 pg/mL and were on stable antiviral therapy. Three groups of 10 children received 6 monthly infusions of 200, 400, or 800 mg/kg of HIVIG, and serial immunologic and virologic assays were performed. HIVIG doses as high as 800 mg/kg were safe and well tolerated. The half-life of HIVIG, determined by serial p24 antibody titers, was 13-16 days, the volume of distribution was 102-113 mL/kg, and clearance was 5.6-6.0 mL/kg/day. Plasma ICD p24 decreased during the infusions, but CD4 cell levels, plasma RNA copy number, cellular virus, immunoglobulin levels, and neutralizing antibody titers were minimally affected by the infusions. Clinical status did not change during the 6-month infusion and 3-month follow-up periods.

Inelastic light scattering by gap excitations of fractional quantum hall states at 1/3 </= nu </= 2/3

We report observations of collective gap excitations of the fractional quantum Hall (FQH) states at filling factors nu = p/(2p+1) ( p = integer), for 1/3</=nu</=2/3, by inelastic light scattering. The collective gap energies at nu = 1/3, 2/5, and 3/7 show a drastic decrease as the value nu = 1/2 is approached. These energies and the one at nu = 3/5 display the linear scaling with (e(2)/epsilonl(0))/|2p+1| that is characteristic of composite fermions in Chern-Simons gauge fields. In a narrow range of nu centered at 1/2, where the FQH gaps collapse, we observe a new excitation mode which exists only at temperatures below 150 mK.

CT-guided fine-needle aspiration biopsy of spinal lesions

PURPOSE

A retrospective study of CT-guided fine-needle aspiration biopsies (FNABs) of spinal lesions performed over a period of 6 years was carried out with the aim of assessing the safety and efficacy of the procedure and to analyse the various approaches used.

MATERIAL AND METHODS

Ninety-three FNABs were performed in 87 patients, 4-70 years of age, under CT guidance. Lytic or mixed vertebral lesions with or without a paraspinal soft tissue component were included in the study. The approach depended on the anatomic region and part of the vertebra involved.

RESULTS

A definite cytological diagnosis was obtained in 77 patients (88.5%); of these, 47 patients had benign lesions and 30 patients had neoplasms. The most common pathologies encountered were tuberculosis (n=33) and metastases (n=17). There were 10 inconclusive FNABs; these showed blood only, necrotic material or scanty material insufficient for diagnosis. There were no procedure-related complications.

CONCLUSION

CT-guided FNAB is a safe and effective technique for the evaluation of spinal lesions and is helpful in planning therapy. Choosing the appropriate approach results in a low complication rate.

Gatekeeping and referral of children and adolescents to specialty care

OBJECTIVE

In this study we examined how gatekeeping arrangements influence referrals to specialty care for children and adolescents in private and Medicaid insurance plans.

DESIGN/PARTICIPANTS

We conducted a prospective study of office visits (n = 27 104) made to 142 pediatricians in 94 practices distributed throughout 36 states in a national primary care practice-based research network. During 10 practice-days, physicians and patients completed questionnaires on referred patients, while office staff kept logs of all visits. Physicians used medical records to complete questionnaires for a subset of patients 3 months after their referral was made.

RESULTS

Gatekeeping arrangements were common among children and adolescents with private (57.8%) and Medicaid (43.3%) insurance. Patients in gatekeeping plans were more likely to be referred with private (3. 16% vs 1.85% visits referred) and Medicaid (5.39% vs 3.73%) financing. Increased parental requests for specialty care among gatekeeping patients did not explain the increased referral rate. Physicians' reasons for making the referral were similar between the two groups. Physicians were less likely to schedule an appointment or communicate with the specialist for referred patients in gatekeeping plans. However, rates of physician awareness that a specialist visit occurred and specialist communication back to pediatricians did not differ between the two groups 3 months after the referrals were made.

CONCLUSIONS

Gatekeeping arrangements are common among insured children and adolescents in the United States. Our study suggests that gatekeeping arrangements increase referrals from pediatricians' offices to specialty care and compromise some aspects of coordination.

The pediatric primary-specialty care interface: how pediatricians refer children and adolescents to specialty care

OBJECTIVE

To describe how pediatricians refer patients to specialists, including frequency of referral decisions, reasons for referral, and types of referrals.

DESIGN

We conducted a prospective study of visits (N = 58 771) made to 142 pediatricians in a national primary care practice-based research network. During 20 consecutive practice days, physicians and parents completed questionnaires for referred patients, and office staff kept logs of all visits. Physicians used medical records to complete questionnaires 3 months after referrals were made.

RESULTS

Pediatricians referred patients to specialists during 2.3% of office visits. Referrals made during telephone conversations with parents accounted for 27.5% of all referrals. The most common reason for referral was advice on diagnosis or treatment (74.3%). Referrals were made most commonly to surgical subspecialists (52.3%), followed by medical subspecialists (27.9%), nonphysicians (11.4%), and mental health practitioners (8.4%). Physicians requested a consultation or a referral with shared management in 75% of cases. Otitis media was the condition referred most often (9.2%). Fifty other conditions accounted for 84.3% of all referrals.

CONCLUSIONS

About 1 in 40 pediatric visits result in referral. Getting advice from a specialist is the most common reason for referral. Pediatricians desire a collaborative relationship with specialists for most of their referred patients. Physician training to increase clinical competence may be most useful for the 50 most commonly referred conditions. Education concerning the referral process should focus on the respective roles of the referring physician and specialist, particularly as they pertain to successful approaches for comanaging referred patients.

Prostaglandin E2 mediates activation of hypothalamic histamine by interleukin-1beta in rats

The present study was designed to investigate the effects of peripheral interleukin-1beta (IL-1beta) on hypothalamic histamine (HA) systems. Intraperitoneal injection of IL-1beta increased the turnover rate of hypothalamic HA, which was assessed by accumulation of tele-methylhistamine after pargyline treatment. IL-1beta increased the activities of both histidine decarboxylase (HDC), an HA synthesizing enzyme, and HA-N-methyltransferase (HMT), an HA catabolizing enzyme. Pretreatment with indomethacin completely blocked the effects induced by IL-1beta on hypothalamic HA. Infusion of prostaglandin E2 (PGE2) into the third cerebroventricle increased the hypothalamic HA turnover rate, and simultaneously activated both HDC and HMT dose-dependently, but intravenous infusion of PGE2 had no effect on the dynamics of hypothalamic HA turnover. These results indicate that hypothalamic PGE2 activated by peripheral administration of IL-1beta, but not by peripheral PGE2, may enhance synthesis and release of hypothalamic HA by activation of HDC, and may facilitate degradation of extracellular histamine by activation of HMT.

Activation of mesangial cell signaling cascades in response to mechanical strain

BACKGROUND

Mesangial cells (MCs) are constantly exposed to pulsatile stretch and relaxation in their role as architectural support for the glomerulus. There is no cell proliferation in normal glomeruli. In contrast, animal models of increased glomerular capillary pressure are characterized by resident glomerular cell proliferation and elaboration of extracellular matrix (ECM) protein, resulting in glomerulosclerosis. This process can be ameliorated by maneuvers, such as angiotensin converting enzyme inhibition, that reduce glomerular capillary pressure. MCs grown on ECM-coated plates and exposed to cyclic stretch/relaxation proliferate and produce ECM protein, suggesting that this may be a useful in vitro model for MC behavior in response to increased physical forces. Previous work has shown induction of c-fos in response to application of mechanical strain to MCs, which may induce increases in AP-1 transcription factor activity, which, in turn, may augment ECM protein and transforming growth factor beta transcription and cell proliferation. Stimuli that lead to c-fos induction pass through mitogen-activated protein kinase (MAPK) pathways. Three MAPK cascades have been characterized in mammalian cells--p44/42 (classic MAPK), the stress-activated protein kinase/Jun terminal kinase (SAPK/JNK) pathway, and p38/HOG--and mechanical strain activates p44/42 and SAPK/JNK in cardiac fibroblasts. However, in contrast to MCs, these cells do not proliferate in response to physical force. Accordingly, we studied activation of the MAPK pathways in MCs exposed to mechanical strain.

METHODS

MCs (passages 5 to 10) cultured on type 1 collagen-coated, flexible-bottom plates were exposed to 30, 60, or 120 minutes of cyclic strain (60 cycles/min) by computer-driven generation of vacuums of -14 and -28 kPa, inducing 20% and 29% elongations in the diameter of the surfaces, respectively. Control MCs were grown on coated rigid bottom plates. Proliferation was assessed at 24 hours by 3H-thymidine incorporation. Protein levels (by Western blot) and activity assays for all three kinase cascades were performed at 30, 60, and 120 minutes.

RESULTS

Cyclic strain/relaxation lead to an approximate doubling of 3H-thymidine incorporation at 24 hours (N = 3, P < 0.05) only in cultures stretched 29%, but not in cultures stretched 20%. At -29% elongation, the increase in 3H-thymidine incorporation was preceded by early activation of MAPK signaling pathways. p44/42 activity increased to a maximum of eightfold greater than control at 60 minutes. p38/HOG activity was not measurable at baseline but was increased markedly at 30 minutes, which was sustained through to 120 minutes. SAPK/JNK activity was present at a very low level in MCs and was not changed by stretch. However, it was markedly increased by sorbitol. In MCs stretched to 20% elongation, lesser increases in p44/42 were seen with a similar time course, whereas no increases in p38/HOG or SAPK could be detected at the time points studied. No increase in any kinase pathway activity was seen at any time in static cultures.

CONCLUSIONS

High-pressure cyclic stretch leads to MC proliferation, preceded by marked activation of p44/42 and p38/HOG MAPKs. Cell proliferation is not seen with low-pressure stretch, and there is only modest p44/42 MAPK activation, suggesting that glomerular capillary hypertension may lead to cell proliferation and injury partly through differential activation of kinase cascades.

Safety and immunogenicity of HIV recombinant envelope vaccines in HIV-infected infants and children. National Institutes of Health-sponsored Pediatric AIDS Clinical Trials Group (ACTG-218)

Study objectives were to evaluate the safety and immunogenicity of three HIV recombinant glycoproteins in HIV-infected infants and children between 1 month and 18 years of age with asymptomatic (P-1) infection. Using Chiron rgp 120 (SF-2) 15 or 50 microg; MicroGeneSys rgp 160 (IIIB) 40 or 320 microg; Genentech rgp120 (MN) 75 or 300 microg; or adjuvant control (Alum or MF-59), children were randomized to a double-blind, placebo-controlled, dose-escalating study of vaccine administered intramuscularly at entry and 1, 2, 3, 4, and 6 months later. No adverse events were attributed to study vaccines. Between 30% and 56% of volunteers exhibited a lymphoproliferative response as defined in terms of stimulation index (SI) to vaccine antigens; 65% of vaccinees but none of placebo recipients exhibited moderate or strong responses after enzyme immunoassay to HIV specific antigens. CD4 cell counts and quantitative HIV culture did not differ significantly among vaccine and control groups, nor were differences found among groups in HIV disease progression. The rgp160 and gp120 subunit vaccines were safe and immunogenic in this population.

Inactivation of the p16 (INK4A) tumor-suppressor gene in pancreatic duct lesions: loss of intranuclear expression

Pancreatic adenocarcinoma develops from histologically identifiable intraductal lesions that undergo a series of architectural, cytological, and genetic changes. Limited genetic evidence recently suggested that the p16 gene plays a role in the progression of these "duct lesions." Duct lesions were identified in pancreata from 33 pancreaticoduodenectomies performed for infiltrating adenocarcinoma. All of these infiltrating adenocarcinomas were previously shown to contain alterations in the p16 gene or its promoter. Monoclonal and polyclonal anti-p16 antibodies were used for histological immunodetection. One hundred twenty-six duct lesions were identified. Nine (30%) of 30 flat, 4 (27%) of 15 papillary, 37 (55%) of 67 papillary with atypia, and 10 (71%) of 14 carcinoma in situ duct lesions showed loss of p16 expression. These included 30% of the flat lesions versus 53% of the nonflat lesions and 29% of the nonatypical lesions versus 58% of the atypical lesions. For both comparisons, the differences were statistically significant (P = 0.036 and P = 0.003, respectively). Loss of p16 expression occurs more frequently, but not exclusively, in higher-grade duct lesions. These data support the hypothesis that pancreatic duct lesions are neoplastic and that they represent the precursors of infiltrating adenocarcinoma. Immunohistochemical detection of p16 provides a new technology to study the genetic alterations in and stages of progression of large numbers of morphologically defined pancreatic duct lesions.

A taxonomy of adolescent health: development of the adolescent health profile-types

OBJECTIVES

The aim of this study was to develop a taxonomy of health profile-types that describe adolescents' patterns of health as self-reported on a health status questionnaire. The intent was to be able to assign individuals to mutually exclusive and exhaustive groups that characterize the important aspects of their health and need for health services.

METHODS

Cluster analytic empirical methods and clinically based conceptual methods were used to identify patterns of health in samples of adolescents from schools and from clinics that serve adolescents with chronic conditions and acute illnesses. Individuals with similar patterns of scores across multiple domains were assigned to the same profile-type. Results from the empirical and conceptually based methods were integrated to produce a practical system for assigning youths to profile-types.

RESULTS

Four domains of health (Satisfaction, Discomfort, Risks and Resilience) were used to group individuals into 13 distinct profile-types. The profile-types were characterized primarily by the number of domains in which health is poor, identifying the unique combinations of problems that characterize different subgroups of adolescents.

CONCLUSIONS

This method of reporting the information available on health status surveys is potentially a more informative way of identifying and classifying the health needs of subgroups in the population than is available from global scores or multiple scale scores. The reliability and validity of this taxonomy of health profile-types for the purposes of planning and evaluating health services must be demonstrated. That is the purpose of the accompanying study.