Characterization of the complete mitochondrial genomes of two Critically Endangered wedgefishes: Rhynchobatus djiddensis and Rhynchobatus australiae

We present the complete mitochondrial genomes of the Critically Endangered whitespotted wedgefish, Rhynchobatus djiddensis (Forsskål, 1775), and bottlenose wedgefish, Rhynchobatus australiae (Whitley, 1939), with the R. djiddensis mitogenome documented for the first time. The genomes for R. djiddensis and R. australiae are 16,799 and 16,805 bp in length, respectively. Both comprise 13 protein-coding regions, 22 tRNA genes, two rRNA genes, and a non-coding control region. All protein-coding regions consistently start with the ATG start codon; however, the alternative start codon GTG is observed at the start of the COX1 gene. NADH2, COX2, and NADH4 have incomplete stop codons: T or TA, and tRNA^Leu and tRNA^Ser , have atypical codons: UAA, UGA, GCU, and UAG. The phylogenetic analysis places R. djiddensis and R. australiae within the Rhynchobatus genus, separate from other families in the order Rhinopristiformes. We also highlight the most variable gene regions to expedite future primer design, of which NADH2 was the most variable (4.5%) when taking gene length into account. These molecular resources could promote the taxonomic resolution of the whitespotted wedgefish species complex and aid in the genetic characterization of populations of these and related species.

Change Management: From Theory to Practice

This article presents a set of change management strategies found across several models and frameworks and identifies how frequently change management practitioners implement these strategies in practice. We searched the literature to identify 15 common strategies found in 16 different change management models and frameworks. We also created a questionnaire based on the literature and distributed it to change management practitioners. Findings suggest that strategies related to communication, stakeholder involvement, encouragement, organizational culture, vision, and mission should be used when implementing organizational change.

Abstract P4-06-11: Cryoablation of murine mammary tumors induce robust immune response

Background: Breast cancer is traditionally not considered as a highly immunogenic disease.

Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer with reported high genomic instability and high mutation rate, indicating the possible presence of neoantigens. Cryoablation, the destruction of cells by ultra-low temperatures, can release these neoantigens and induce a tumor specific immune response.

We hypothesized these neoantigens might be sufficient to trigger a robust immune response to prevent and/or reduce spread and relapse of TNBC.

In this pilot study we cryoablated orthotopical 4T1 tumors in immune competent Balb/c mice and compared the results to surgery to evaluate 1) possible induction of immune responses and 2) effects on metastases formation.

Methods: We used 4T1 mammary carcinoma cells to initiate tumor growth in the mammary fatpad. Tumors were treated by cryoablation, cryoablation followed by surgery (cryo-surgery), or surgery alone. Tumor growth was followed and allowed to reach 3-4mm in largest dimension. Animals were euthanized 7 days post-treatment and tissues were collected to assess cytokine levels and presence of dissociated 4T1 cells. Single-cell suspensions of tumor, tumor-draining lymph node [TDLN], and spleen were tested for secretion of mouse Th1/Th2 cytokines using a bead array and measured by flow cytometery. Possible metastatic spread was assessed by a clonogenic assay using cells from venous blood, lung, and brain. Cell suspensions were seeded in growth medium supplemented with the selection agent 6-thioguanine, allowing only resistant 4T1 cells to form colonies.

Results: Cryoablation transformed tumors into a gelatinous mass surrounded by a fibrotic capsule, as typically seen in the clinic. Frozen sections of tumors revealed a necrotic core and infiltrating lymphocytes in the microenvironment. These animals displayed robust increases of Th1 and Th2 cytokines in both spleen and TDLN compared to animals with cryo-surgery treatment. TDLN of animals with surgically excised tumors secreted only IL-2. Circulating tumor cells were found in animals prior to treatment, while no 4T1 colonies formed from cell suspensions of lung and brain tissue [N=8]. At end-point, the surgery alone group had more 4T1 foci formed from lung and brain [mean foci /animal = 6.25 and 0.75, respectively; N=6] than the other two groups. Two animals in this group progressed and were euthanized early due to numerous lung metastases. The cryoablated group had the lowest number of foci formed in the lung and brain [2.25 and 0 respectively; N=8], and all animals were healthy at the predetermined end-point. Mean foci formation in the cryo-surgery group [N=7] was in-between the two other groups and one animal was euthanized early due to metastatic burden 5 days after surgery.

Conclusion: Cryoablation of TNBC can induce stimulatory immune responses in vivo. These immune responses might explain why animals treated with cryoablation, though having circulating tumor cells at the time of treatment, exhibited fewer micro metastatic growths compared to surgery alone and the cryo-surgery combination. On-going experiments aim to identify long-term effects of cryoablation on the formation of metastatic foci and growth.

Citation Format: Klein JD, Aukers Z, Kennedy J, Ciocca RM, Sabol JL, Carp NZ, Wallon UM. Cryoablation of murine mammary tumors induce robust immune response [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-06-11.

Protecting children and families from tobacco and tobacco-related NCDs in the Western Pacific: good practice examples from Malaysia, Philippines and Singapore

BACKGROUND

Non-communicable diseases (NCDs) are generally considered diseases of adulthood, but NCD risk factors like tobacco use often are taken up during childhood and adolescence, and second-hand smoke exposure affects child survival and development.

METHODS

At a regional meeting of the Asia Pacific Child and Family Health Alliance for Tobacco Control, members reviewed existing good practices of child-focused tobacco control approaches using health promotion strategies. These interventions were implemented nationally in Malaysia, the Philippines and Singapore.

RESULTS

Three good practice national examples were identified that focused on creating supportive tobacco-free environments and upgrading cessation skills among paediatricians. These country examples highlight strategic areas to protect children and families from the harms of tobacco, as part of NCD prevention and control. Training paediatricians in brief cessation advice has enabled them to address tobacco-using parents. Fully enforcing smoke-free public areas has led to an increase in smoke-free homes. The Tobacco Free Generation is a tobacco control 'endgame' strategy that taps into a social movement to deglamorize tobacco use and empower youth born in and after year 2000 to reject tobacco and nicotine addiction.

CONCLUSION

Tobacco control is pivotal in the fight against NCDs; health promotion strategies to protect children and youth from tobacco have a critical role to play in NCD prevention and control. Frontline health workers, including primary care paediatricians, need to step up and actively advocate for full implementation of the WHO Framework Convention on Tobacco Control, including tobacco tax increases and smoke-free areas, while monitoring patients and their parents for tobacco use and second-hand smoke exposure, preventing adolescent smoking uptake, and offering cessation support. A life-course approach incorporating child-focused efforts to prevent initiation of smoking and second-hand smoke exposure with measures promoting cessation among parents will offer the greatest chance of overcoming future tobacco-related NCD burden.

Computer-based or human patient simulation-based case analysis: which works better for teaching diagnostic reasoning skills?

AIM

The purpose of this study was to determine whether a difference exists in learner performance and the type and frequency of diagnostic reasoning skills used, based on the method of case presentation.

BACKGROUND

Faculty can select from a variety of methods for presenting cases when teaching diagnostic reasoning, but little evidence exists with regard to how students use these skills while interacting with the cases.

METHOD

A total of 54 nursing students participated in two case analyses using human patient and computer-based simulations. Participant performance and diagnostic reasoning skills were analyzed.

RESULTS

Performance was significantly better with the human patient simulation case. All diagnostic reasoning skills were used during both methods of case presentation, with greater performance variation in the computer-based simulation.

CONCLUSION

Both human patient and computer-based simulations are beneficial for practicing diagnostic reasoning skills; however, these findings support the use of human patient simulations for improving student performance in case synthesis.

Computational modeling of direct neuronal recruitment during intracortical microstimulation in somatosensory cortex

OBJECTIVE

Electrical stimulation of cortical tissue could be used to deliver sensory information as part of a neuroprosthetic device, but current control of the location, resolution, quality, and intensity of sensations elicited by intracortical microstimulation (ICMS) remains inadequate for this purpose. One major obstacle to resolving this problem is the poor understanding of the neural activity induced by ICMS. Even with new imaging methods, quantifying the activity of many individual neurons within cortex is difficult.

APPROACH

We used computational modeling to examine the response of somatosensory cortex to ICMS. We modeled the axonal arbors of eight distinct morphologies of interneurons and seven types of pyramidal neurons found in somatosensory cortex and identified their responses to extracellular stimulation. We then combined these axonal elements to form a multi-layered slab of simulated cortex and investigated the patterns of neural activity directly induced by ICMS. Specifically we estimated the number, location, and variety of neurons directly recruited by stimulation on a single penetrating microelectrode.

MAIN RESULTS

The population of neurons activated by ICMS was dependent on both stimulation strength and the depth of the electrode within cortex. Strikingly, stimulation recruited interneurons and pyramidal neurons in very different patterns. Interneurons are primarily recruited within a dense, continuous region around the electrode, while pyramidal neurons were recruited in a sparse fashion both near the electrode and up to several millimeters away. Thus ICMS can lead to an unexpectedly complex spatial distribution of firing neurons.

SIGNIFICANCE

These results lend new insights to the complexity and range of neural activity that can be induced by ICMS. This work also suggests mechanisms potentially responsible for the inconsistency and unnatural quality of sensations initiated by ICMS. Understanding these mechanisms will aid in the design of stimulation that can be used to generate effective sensory feedback for neuroprosthetic devices.

Adolescents' perceptions of the internet as a health information source

Focal points

A randomized controlled trial of telephone peer support's influence on breastfeeding duration in adolescent mothers

PURPOSE

Adolescent mothers breastfeed less often and for a shorter duration than adult mothers. This randomized controlled trial was designed to evaluate the effect of telephone peer support on breastfeeding duration among adolescents.

METHODS

Five adolescents who had previously breastfed were trained to provide peer support. Seventy-eight breastfeeding mothers were randomly assigned to an intervention group that received telephone calls from the peer support persons (n = 38) or to a control group that did not receive support (n = 40). An independent interviewer telephoned all new mothers weekly to document feeding patterns. Peer support persons, subjects, and the interviewer were all blinded to the research hypothesis and to group assignment. The primary outcome variable was "any breastfeeding" duration, i.e., the age at complete breastfeeding cessation. A secondary outcome variable was exclusive breastfeeding, i.e., the age at first introduction of any supplement.

RESULTS

"Any breastfeeding" duration did not differ significantly between the groups (median 75 days in the intervention group vs. 35 days in the control group, p = 0.26). Among the 13 intervention and 11 control mothers who were exclusively breastfeeding at the time of hospital discharge, the duration of exclusive breastfeeding was increased in the intervention group (median 35 days vs. 10 days, p = 0.004).

CONCLUSIONS

This study did not demonstrate a significant effect of peer support on "any breastfeeding" duration. In contrast, exclusive breastfeeding duration appeared to be extended by peer support. This latter finding would benefit from confirmation in future studies. However, unless better methods are developed for retaining peers, this is likely to be a labor-intensive approach to extending exclusive breastfeeding duration among adolescent mothers.

X-chromosome linked inhibitor of apoptosis protein inhibits muscle proteolysis in insulin-deficient mice

Loss of muscle protein is a serious complication of catabolic diseases and contributes substantially to patients' morbidity and mortality. This muscle loss is mediated largely by the activation of the ubiquitin-proteasome system; however, caspase-3 catalyzes an initial step in this process by cleaving actomyosin into small protein fragments that are rapidly degraded by the proteasome-dependent proteolytic pathway. We hypothesized that X-chromosome linked inhibitor of apoptosis protein (XIAP), an endogenous caspase-3 inhibitor, would block this first step in the cleavage of actomyosin that would make XIAP a candidate for treating muscle wasting. To determine if XIAP could attenuate muscle protein degradation, we used a recombinant lentivirus (Len-XIAP) encoding the full-length human XIAP cDNA to express XIAP in vivo. In muscle of streptozotocin-treated insulin-deficient mice, total muscle protein degradation, caspase-3 activity, and myofibril destruction were increased while XIAP was decreased. Overexpression of XIAP in these mice attenuated the excessive muscle protein degradation. Increased proteasome activity, caspase-3 activity and myofibril protein breakdown were all reduced. The ability of XIAP to prevent the loss of muscle protein suggests that XIAP could be a therapeutic reagent for muscle atrophy in catabolic diseases.

Adrenalectomy blocks the compensatory increases in UT-A1 and AQP2 in diabetic rat kidney

In normal rats we showed that glucocorticoids participate in the downregulation of UT-A1 protein abundance in the inner medullary tip and in lowering of basal and vasopressin-stimulated facilitated urea permeability in terminal IMCDs. To examine the relevance of this response to a rat model of human disease, we studied rats with uncontrolled diabetes mellitus (DM) induced by streptozotocin (STZ), since these rats have increased corticosterone production and urea excretion. We found that at 3 days of DM, UT-A1 protein abundance is downregulated in the inner medullary tip compared to pair-fed control rats, while DM for more than 7 days caused an increase in UT-A1. To test whether adrenal steroids could be a mechanism contributing to the latter increase, we studied adrenalectomized rats (ADX), ADX rats given STZ to induce diabetes (ADX + STZ), and ADX + STZ rats receiving exogenous aldosterone or dexamethasone. In contrast to control rats, UT-A1 protein abundance was not increased by prolonged DM in the ADX rats. Aquaporin 2 (AQP2) was not increased in the inner medullas of 10-day DM rats either. However, UT-A1 protein abundance was significantly reduced in the inner medullary tips from both diabetic aldosterone-treated (40 +/- 2%) and dexamethasone-treated (43 +/- 2%) ADX rats compared to diabetic ADX rats without steroid replacement. AQP2 was unaffected by steroid hormone treatments. Thus, both mineralocorticoids and glucocorticoids downregulate UT-A1 protein abundance in rats with uncontrolled diabetes mellitus for 10 days. These results suggest that: 1) the increase in UT-A1 observed in DM is dependent upon having adrenal steroids present; and 2) adrenal steroids are not sufficient to enable the compensatory rise in UT-A1 to a steroid-deficient diabetic animal.

Renal ENaC subunit, Na-K-2Cl and Na-Cl cotransporter abundances in aged, water-restricted F344 x Brown Norway rats

Renal sodium reabsorption is a key determinant of final urine concentration. Our aim was to determine whether differences existed between aged and young rats in their response to water restriction with regard to the regulation of abundance of any of the major distal renal sodium transporter proteins. Male Fisher 344 x Brown Norway (F344 x BN) rats of 3-, 10-, 24-, or 31 months of age (3M, 10M, 24M, or 31M) were either water restricted (WR) for 5 days or control (ad libitum water). Major renal sodium transporters and channel subunits were evaluated by immunoblotting and immunohistochemistry. Age did not significantly affect plasma arginine vasopressin or aldosterone levels, but renin activity was only 8% in 31M-WR rats relative to 3M-WR (P<0.05). Extreme aging (31M) led to decreased outer medullary abundance of the bumetanide-sensitive Na-K-2Cl cotransporter and decreased cortical abundance of the beta- and gamma-subunits (70-kDa band) of the epithelial sodium channel (ENaC) (P<0.05). Water restriction significantly (P<0.05) increased the abundance of Na-K-2Cl cotransporter (NKCC2) and Na-Cl cotransporter (NCC) across ages. However, these increases were significantly blunted as rats aged. Mean band densities were increased in WR rats (relative to age controls) by 54 and 106% at 3M, but only 25 and 29% at 24M and 0 and 6% at 31M for NKCC2 and NCC, respectively. Aged F344 x BN rats have reduced basal distal tubular renal sodium transporter abundances and blunted upregulation during water restriction, which may contribute to decreased urinary concentrating capacity.

Youth and tobacco

Youth around the world take up smoking and use tobacco products at high rates. Young people may not grasp the long-term consequences of tobacco use, although tobacco consumption and exposure has been shown to have significant negative health effects. Youth use a variety of tobacco products that are smoked, chewed, or sniffed, including machine-manufactured cigarettes, cigars, bidis, kreteks, sticks, and snuff. Prevention efforts have focused on countering those aspects that are believed to contribute to smoking uptake, such as tobacco industry advertising and promotion, and access to tobacco. There are many aspects of tobacco promotion through the media that have been more difficult to control, however, such as product placement within popular cinema movies. Once a youth has taken up tobacco, he or she is more likely than an adult to become addicted and should be offered treatment for tobacco cessation. Although there is not yet sufficient evidence to prove efficacy, the same treatments are suggested for youth as are recommended for adults, including nicotine replacement products. Given the severity of the tobacco epidemic worldwide and the devastating health effects on an individual and population basis, there are currently many efforts to curtail the tobacco problem, including the World Health Organization (WHO) sponsored Framework Convention on Tobacco Control. It is through comprehensive and collaborative efforts such as this that the global hazard of tobacco is most likely to be overcome.

Effect of nitrogen intake on nitrogen recycling and urea transporter abundance in lambs

Urea recycling in ruminants has been studied extensively in the past, but the mechanisms regulating the amount of urea recycled or excreted remain obscure. To elucidate the role of urea transporters (UT) in N recycling, nine Dorset-Finn ewe lambs (20.8 +/- 0.8 kg) were fed diets containing 15.5, 28.4, and 41.3 g of N/kg of DM for 25 d. Nitrogen balance and urea N kinetics were measured during the last 3 d of the period. Animals were then slaughtered and mucosa samples from the rumen, duodenum, ileum, and cecum, as well as kidney medulla and liver, were collected. Increasing N intake tended to increase N balance quadratically (1.5, 5.1, and 4.4 +/- 0.86 g of N/d, P < 0.09), and linearly increased urinary N excretion (2.4, 10, and 16.5 +/- 0.86 g N/d, P < 0.001) and plasma urea N concentration (4.3, 20.3, and 28.4 +/- 2.62 mg of urea N/dL, P < 0.001), but did not affect fecal N excretion (5.0 +/- 0.5 g of N/d; P < 0.94). Urea N production (2.4, 11.8, and 19.2 +/- 0.83 g of N/d; P < 0.001) and urinary urea N excretion (0.7, 7.0, and 13.4 +/- 0.73 g N/d; P < 0.001) increased linearly with N intake, as well as with the urea N recycled to the gastrointestinal tract (1.8, 4.8, and 5.8 +/- 0.40 g of N/d, P < 0.001). No changes due to N intake were observed for creatinine excretion (518 +/- 82.4 mg/d; P < 0.69) and clearance (46 +/- 10.7 mL/min; P < 0.56), but urea N clearance increased linearly with N intake (14.9, 24.4, and 34.9 +/- 5.9 mL/min; P < 0.04). Urea N reabsorption by the kidney tended to decrease (66.3, 38.5, 29.1 +/- 12.6%; P < 0.06) with increasing N content of the diet. Increasing the level of N intake increased linearly the weight of the liver as a proportion of BW (1.73, 1.88, and 2.22 +/- 0.15%, P < 0.03) but only tended to increase the weight of the kidneys (0.36, 0.37, and 0.50 +/- 0.05%, P < 0.08). Urea transporter B was present in all the tissues analyzed, but UT-A was detected only in kidney medulla, liver, and duodenum. Among animals on the three diets, no differences (P > 0.10) in UT abundance, quantified by densitometry, were found. Ruminal-wall urease activity decreased linearly (P < 0.02) with increasing level of N intake. Urease activity in duodenal, ileal, and cecal mucosa did not differ from zero (P > 0.10) in lambs on the high-protein diet. In the present experiment, urea transporter abundance in the kidney medulla and the gastrointestinal tract did not reflect the increase in urea-N reabsorption by the kidney and transferred into the gut.

Improving adolescent health outcomes

Adolescent morbidity and mortality are more often due to preventable causes and to risky behavioral choices than to "natural" causes, such as cardiovascular disease or cancer. The leading causes of death among adolescents in Western, industrialized nations are unintentional injuries, especially motor vehicle crashes, homicide, and suicide. The physical and cognitive development of adolescents also results in increased risky behavioral choices, and to high rates of sexually transmitted diseases, substance use and misuse, and inadequate nutrition. These lifestyle choices also have repercussions that last into adulthood. Brief counseling interventions by physicians or other clinicians have been shown to be effective in modifying health risk behaviors in adolescents. Adolescents also have indicated both a belief that physicians should counsel them on risk behaviors and a willingness to discuss risk behaviors if asked about them in a confidential manner. In this paper, we review the leading causes of adolescent morbidity and mortality in the United States and Western Europe, including injuries, violence, depression and suicide, substance use, sexual activity, and nutrition, physical activity, and eating disorders. In addition, we describe the effectiveness of physician counseling for reduction or prevention of specific risk behaviors and the importance of providing comprehensive, confidential care. Additionally, we describe the results of a recent study of implementation of Adolescent Preventive Service Guidelines in community and migrant health centers that increased risky behavior screening and counseling for adolescent patients seen for routine/well care visits.

The care of HIV-infected adults in rural areas of the United States

OBJECTIVE

This study describes the population of HIV-infected adults receiving care in rural areas of the United States and compares HIV care received in rural and urban areas.

METHODS

Interviews were conducted with a nationally representative sample of 367 HIV-infected adults receiving health care in rural areas and 2806 HIV-infected adults receiving health care in urban areas of the contiguous United States.

RESULTS

We estimate that 4800 HIV-infected persons received medical care in rural areas during the first half of 1996. Patients in rural HIV care were more likely than patients in urban HIV care to receive care from providers seeing few (<10) HIV-infected patients (38% vs. 3%; p <.001). Rural care patients were less likely than urban care patients to have taken highly active antiretroviral agents (57% vs. 73%; p <.001) or Pneumocystis carinii pneumonia prophylactic medication when indicated (60% vs. 75%; p =.006).

CONCLUSIONS

Few American adults received HIV care in rural areas of the United States. Our findings suggest ongoing disparities between urban and rural areas in access to high-quality HIV care.

Growth factors stimulate the Na-K-2Cl cotransporter NKCC1 through a novel Cl(-)-dependent mechanism

The Na-K-2Cl cotransporter NKCC1 is an important volume-regulatory transporter that is regulated by cell volume and intracellular Cl(-). This regulation appears to be mediated by phosphorylation of NKCC1, although there is evidence for additional, cytoskeletal regulation via myosin light chain (MLC) kinase. NKCC1 is also activated by growth factors and may contribute to cell hypertrophy, but the mechanism is unknown. In aortic endothelial cells, NKCC1 (measured as bumetanide-sensitive (86)Rb(+) influx) was rapidly stimulated by serum, lysophosphatidic acid, and fibroblast growth factor, with the greatest stimulation by serum. Serum increased bumetanide-sensitive influx significantly more than bumetanide-sensitive efflux (131% vs. 44%), indicating asymmetric stimulation of NKCC1, and produced a 17% increase in cell volume and a 25% increase in Cl(-) content over 15 min. Stimulation by serum and hypertonic shrinkage were additive, and serum did not increase phosphorylation of NKCC1 or MLC, and did not decrease cellular Cl(-) content. When cellular Cl(-) was replaced with methanesulfonate, influx via NKCC1 increased and was no longer stimulated by serum, whereas stimulation by hypertonic shrinkage still occurred. Based on these results, we propose a novel mechanism whereby serum activates NKCC1 by reducing its sensitivity to inhibition by intracellular Cl(-). This resetting of the Cl(-) set point of the transporter enables the cotransporter to produce a hypertrophic volume increase.

Teratogen update: Lyme disease

We reviewed the world literature concerning the reproductive effects of Lyme disease (LD). Borrelia burgdorferi, which is the etiology of LD, is a spirochete and, as such, may share the potential for causing fetal infection, which may occur in the setting of maternal spirochetemia. Information concerning the effects of gestational LD derives from case reports and series, epidemiologic studies, and experimental animal models. Although provocative, these studies fail to define a characteristic teratogenic effect. However, skin and cardiac involvement have predominated in some reports. Pregnancy wastage has been suggested primarily by animal studies. Gestational LD appears to be associated with a low risk of adverse pregnancy outcome, particularly with appropriated antibiotic therapy. Suggestions for management of clinical situations are presented.

Cat-scratch disease presenting as multifocal osteomyelitis with thoracic abscess

The case of a 4-year-old girl who presented with fever and back pain after being scratched by a kitten is presented. The diagnosis of cat scratch disease osteomyelitis was made by the detection of Bartonella henselae DNA by PCR analysis of a rib abscess aspirate.

Localization of the urea transporter UT-B protein in human and rat erythrocytes and tissues

A new polyclonal antibody to the human erythrocyte urea transporter UT-B detects a broad band between 45 and 65 kDa in human erythrocytes and between 37 and 51 kDa in rat erythrocytes. In human erythrocytes, the UT-B protein is the Kidd (Jk) antigen, and Jk(a+b+) erythrocytes express the 45- to 65-kDa band. However, in Jk null erythrocytes [Jk(a-b-)], only a faint band at 55 kDa is detected. In kidney medulla, a broad band between 41 and 54 kDa, as well as a larger band at 98 kDa, is detected. Human and rat kidney show UT-B staining in nonfenestrated endothelial cells in descending vasa recta. UT-B protein and mRNA are detected in rat brain, colon, heart, liver, lung, and testis. When kidney medulla or liver proteins are analyzed with the use of a native gel, only a single protein band is detected. UT-B protein is detected in cultured bovine endothelial cells. We conclude that UT-B protein is expressed in more rat tissues than previously reported, as well as in erythrocytes.

UT-A urea transporter protein in heart: increased abundance during uremia, hypertension, and heart failure

Urea transporters have been cloned from kidney medulla (UT-A) and erythrocytes (UT-B). We determined whether UT-A proteins could be detected in heart and whether their abundance was altered by uremia or hypertension or in human heart failure. In normal rat heart, bands were detected at 56, 51, and 39 kDa. In uremic rats, the abundance of the 56-kDa protein increased 1.9-fold compared with pair-fed, sham-operated rats, whereas the 51- and 39-kDa proteins were unchanged. We also detected UT-A2 mRNA in hearts from control and uremic rats. Because uremia is accompanied by hypertension, the effects of hypertension per se were studied in uninephrectomized deoxycorticosterone acetate salt-treated rats, where the abundance of the 56-kDa protein increased 2-fold versus controls, and in angiotensin II-infused rats, where the abundance of the 56 kDa protein increased 1.8-fold versus controls. The 51- and 39-kDa proteins were unchanged in both hypertensive models. In human left ventricle myocardium, UT-A proteins were detected at 97, 56, and 51 kDa. In failing left ventricle (taken at transplant, New York Heart Association class IV), the abundance of the 56-kDa protein increased 1.4-fold, and the 51-kDa protein increased 4.3-fold versus nonfailing left ventricle (donor hearts). We conclude that (1) multiple UT-A proteins are detected in rat and human heart; (2) the 56-kDa protein is upregulated in rat heart in uremia or models of hypertension; and (3) the rat results can be extended to human heart, where 56- and 51-kDa proteins are increased during heart failure.

97- and 117-kDa forms of collecting duct urea transporter UT-A1 are due to different states of glycosylation

UT-A1 is an extremely hydrophobic 929-amino acid integral membrane protein, expressed in the renal inner medullary collecting duct, with a central role in the urinary concentrating mechanism. Previous immunoblotting studies in rats have revealed that UT-A1 is present in kidney in 97- and 117-kDa monomeric forms and that the relative abundance of the two forms is altered by vasopressin treatment and other treatments that altered urinary inner medullary urea concentration. The present studies were carried out using protein chemistry techniques to determine the origin of the two forms. Peptide-directed polyclonal antibodies targeted to five sites along the polypeptide sequence from the NH2 to the COOH terminus labeled both forms, thus failing to demonstrate a significant deletion in the primary amino acid chain. The 97- and 117-kDa monomeric forms were both reduced to 88 kDa by deglycosylation with N-glycosidase F, indicating that a single polypeptide chain is glycosylated to two different extents. Studies using nonionic detergents for membrane solubilization or using homobifunctional cross-linkers demonstrated that UT-A1 exists as a 206-kDa protein complex in native kidney membranes. The mobility of this complex was also increased by deglycosylation. Both the 97- and 117-kDa proteins, as well as the 206-kDa complex, were immunoprecipitated with UT-A1 antibodies. We conclude that UT-A1 is a glycoprotein and that the two monomeric forms (97 and 117 kDa) in inner medullary collecting duct are the consequence of different states of glycosylation.

In vitro activities of linezolid, meropenem, and quinupristin-dalfopristin against group C and G streptococci, including vancomycin-tolerant isolates

The in vitro activities of meropenem, linezolid, quinupristin-dalfopristin, vancomycin, and penicillin against 130 clinical isolates of group C and G streptococci, including vancomycin-tolerant isolates, were evaluated. Meropenem, linezolid, quinupristin-dalfopristin, vancomycin, and penicillin MICs at which 90% of the isolates were inhibited were 0.06, 2.0, 0.25, 0.5, and < or = 0.016 microg/ml, respectively. Meropenem, linezolid, quinupristin-dalfopristin, and penicillin were active against group C and G streptococci, including vancomycin-resistant strains.

Performance of a predictive model for streptococcal pharyngitis in children

CONTEXT

Group A beta-hemolytic streptococcus (GABHS) pharyngitis is a common childhood illness. The clinical diagnosis is difficult to determine and laboratory tests have limitations; hence, the condition is generally overdiagnosed and overtreated. Several clinical pediatric-specific predictive models have been published but none have been prospectively studied.

OBJECTIVE

To test the performance of a previously published predictive model for GABHS pharyngitis in children in different clinical settings and during different seasons.

DESIGN

Prospective cohort study.

SETTINGS

Pediatric emergency department and 2 pediatric outpatient clinics.

PATIENTS

Children aged between 1 and 18 years with pharyngitis on initial examination at study sites between April 1, 1999, and March 31, 2000.

INTERVENTIONS

Recording of clinical features during initial evaluation using a standardized form and recovery of GABHS from patients' throats using reference standard methods.

MAIN OUTCOME MEASURES

Posttest probability for GABHS positive throat culture associated with the model's positive predictors (moderate to severe tonsillar swelling, cervical lymphadenopathy [moderate to severe tenderness and enlargement of cervical lymph nodes], scarletiniform rash, and the absence of coryza) and the models' negative predictors (absence of the above signs and the presence of coryza).

RESULTS

Of 587 patients analyzed, 218 (37%) had a positive throat culture for GABHS. Forty-nine percent were boys. Mean +/- SD age was 6.7 +/- 3.9 years. There was no difference between the subsets within the sample. The posttest probability values for a positive throat culture associated with positive and negative predictors of the model were 79% and 12%, respectively.

CONCLUSIONS

A pediatric predictive model for GABHS pharyngitis performed better than physicians' subjective estimates for a positive throat culture and was comparable with a rapid antigen detection test. The model performed consistently well in different populations and across seasons. It can be useful if reliable microbiological testing and/or follow-up are not attainable.

Care of the adolescent sexual assault victim

Sexual assault is a broad-based term that encompasses a wide range of sexual victimizations, including rape. Since the American Academy of Pediatrics published its last policy statement on this topic in 1994, additional information and data have emerged about sexual assault and rape in adolescents, the adolescent's perception of sexual assault, and the treatment and management of the adolescent who has been a victim of sexual assault. This new information mandates an updated knowledge base for pediatricians who care for adolescent patients. This statement provides that update, focusing on sexual assault and rape in the adolescent population.

Condom use by adolescents

The use of condoms as part of the prevention of unintended pregnancies and sexually transmitted diseases (STDs) in adolescents is evaluated in this policy statement. Sexual activity and pregnancies decreased slightly among adolescents in the 1990s, reversing trends that were present in the 1970s and 1980s, while condom use among adolescents increased significantly. These trends likely reflect initial success of primary and secondary prevention messages aimed at adolescents. Rates of acquisition of STDs and human immunodeficiency virus (HIV) among adolescents remain unacceptably high, highlighting the need for continued prevention efforts and reflecting the fact that improved condom use can decrease, but never eliminate, the risk of acquisition of STDs and HIV as well as unintended pregnancies. While many condom education and availability programs have been shown to have modest effects on condom use, there is no evidence that these programs contribute to increased sexual activity among adolescents. These trends highlight the progress that has been made and the large amount that still needs to be accomplished.

Delivery of smoking prevention and cessation services to adolescents

OBJECTIVES

To describe the delivery of smoking prevention and cessation screening and counseling practices to adolescents and to examine the effect of physician specialty, sex, practice characteristics, and familiarity with preventive care guidelines on the delivery of smoking cessation counseling services.

METHODS

Cross-sectional self-reported survey of pediatricians and family physicians in 3 New York metropolitan statistical areas who had seen 1 or more adolescents for well care within the past 6 months.

RESULTS

Of 564 eligible physicians, 371 (66%) responded. Physicians reported asking most adolescents about smoking (91%) but were less likely to ask about peer smoking use (41%) or smokeless tobacco use (32%). Similarly, they reported assessing motivation to quit for 81% of smokers, but less often helped set quit dates (34%) or scheduled follow-up visits (28%). Family physicians were more likely to provide more effective smoking cessation interactions than pediatricians (mean smoking counseling performance score, 61 vs. 53; P<.001). Family physicians were also more likely to be familiar with National Cancer Institute guidelines than pediatricians (48% vs. 27%; P<.001). Female physicians reported having spent more time with their last adolescent patient (mean, 26 vs 21 minutes; P<.001) and more often spent time alone with adolescent patients (85% vs. 76% of visits; P<.001) than did male physicians. In multivariate modeling, specialty, familiarity with National Cancer Institute guidelines, time spent, and confidentiality factors were associated with better smoking counseling performance.

CONCLUSION

Familiarity with smoking cessation guidelines and physician's specialty and practice style with adolescents are associated with better delivery of tobacco cessation counseling to adolescents.

Where are we on teen sex?: Delivery of reproductive health services to adolescents by family physicians

BACKGROUND AND OBJECTIVES

This study describes variation in reproductive health preventive services delivery to adolescents by family physicians in Upstate New York.

METHODS

We surveyed a stratified random sample of 354 family physicians from three New York State metropolitan statistical areas about the proportion of their adolescent patients (ages 15-18) to whom they deliver preventive reproductive health interventions. Responses were averaged to create a preventive care practice score.

RESULTS

Of 295 eligible respondents, 179 returned completed surveys (61%). Eighty-one percent were male. Respondents did not vary by geographical area. However, female family physicians were less likely to respond than males, and olderfamily physicians were less likely to respond than more-recent graduates. On average, family physicians reported asking 79% of their adolescent patients about contraceptive use, 73% about condom use, 72% about sexual relationships, and 61% about sexual behaviors. Only 36% reported asking teens when they thought sex was appropriate, and 30% had discussed sexual orientation. Seventy-six percent of physicians discussed adolescents' risks of HIV with adolescent patients, 78% advised adolescent patients to use condoms, 21% gave handouts about HIV, and 9% gave condoms to adolescent patients. Factors associated with provision of more preventive reproductive services included regularly discussing confidentiality, more-recent medical school graduation, placing a high value on the American Academy of Family Physicians recommendations, having read Centers for Disease Control immunization guidelines, having read American Academy of Pediatrics guidelines, and female gender Overall, these factors explained 26% of the variance in provision of preventive reproductive services.

CONCLUSIONS

Family physicians report providing most reproductive preventive services to more than half of their patients. Female physicians, older physicians, physicians who regularly discuss confidentiality, and physicians who have a more-positive attitude toward andfamiliarity with preventive care guidelines are more likely to provide reproductive health screening and counseling during adolescent visits.

Improving adolescent preventive care in community health centers

OBJECTIVE

To evaluate implementation of the Guidelines for Adolescent Preventive Services (GAPS) in Community and Migrant Health Centers (CMHCs).

DESIGN

Before and after comparison of health center policy, clinician and adolescent self-report, and chart reviews in 5 CMHCs.

PARTICIPANTS

Eighty-one preintervention and 80 one-year postintervention providers and 318 preintervention and 331 postintervention 14- to 19- year-old adolescent patients being seen for well visits at 5 CMHCs.

INTERVENTION

Health center staff were trained to implement GAPS and were provided resource materials, patient questionnaires, and clinician manuals.

MAIN OUTCOME MEASURES

Delivery of and receipt of preventive services and perceived access to care.

RESULTS

CMHC systems changes were related to stronger leadership commitment to adolescent care. Providers reported high levels of preventive services delivery before and after guideline implementation. After guideline implementation, adolescents reported increases in having discussed prevention content with providers in 19 of 31 content areas, including increased discussion of physical or sexual abuse (10% before to 22% after), sexual orientation (13% to 27%), fighting (6% to 21%), peer relations (37% to 52%), suicide (7% to 22%), eating disorders (11% to 28%), weapons (5% to 22%), depression (16% to 34%), smokeless tobacco (10% to 29%), and immunizations (19% to 48%). Adolescents were also more likely to report knowing where to get reproductive or mental health services and were more likely to have received health education materials. Implementation also increased documentation of recommended screening and counseling in 51 of 79 specific content areas assessed in chart reviews.

CONCLUSION

Implementing GAPS increased the receipt of preventive services at these health centers. Adolescents received more comprehensive screening and counseling, more health education materials, and had greater access to care after implementation. GAPS implementation may help improve the quality of care for adolescents.

Surface-enhanced raman detection of 2,4-dinitrotoluene impurity vapor as a marker to locate landmines

Time, cost, and casualties associated with demining efforts underscore the need for improved detection techniques. Reduction in the number of false positives by directly detecting the explosive material, rather than casing material, is desirable. The desired field sensor must, at a minimum, demonstrate reproducibility, the necessary level of sensitivity, portability, instrumental stability, and fast system response times. Ideally, vibrational spectroscopic techniques have the potential to remove false positives, since every chemical has a unique bond structure. Herein, we demonstrate the capabilities of surface-enhanced Raman spectroscopy to detect the chemical vapor signature emanating from buried TNT-based landmines. We present reproducible results obtained from blind tests controlled by the Defense Advanced Research Projects Agency (DARPA) that demonstrate vapor detection of 2,4-dinitrotoluene at concentration levels of 5 ppb or less. The results presented used acquisition times of 30 s on a fieldable system and showed that SERS can be a significant improvement over current landmine detection methods.

Homeless and runaway youths' access to health care

PURPOSE

To describe use of health services and self-reported access to regular and emergency care by homeless adolescents and street youth.

METHODS

Interviewer-administered surveys addressed use of health services, availability of sources of care for emergencies, and types of care sources used. An abbreviated version of the questionnaire used for youth in shelters was used for street youth. A nationally representative sample of 640 sheltered youth and a purposive sample of 600 street youth aged 12-21 years were interviewed. All data were collected in 1992.

RESULTS

Half of street youth and 36% of sheltered youth did not have a regular source of health care (p < or =.05). One-fourth of street youth and 18% of sheltered youth also reported serious health problems within the past year (p < or =.05). Street youth were more likely than sheltered youth to have used emergency treatment (36% vs. 29%; p < or =.05) and alcohol- or drug-related emergency treatment (25% vs. 13%; p < or =.05). Sheltered youth with a regular source of care were more likely to use nonemergency sites than those without a source of primary care (46% vs. 20%; p < or =.001). Few sheltered or street youth perceived shelter clinics, clinics for runaway youth, or free youth clinics to be available to meet their emergency care needs.

CONCLUSIONS

Significant numbers of homeless youth did not have a regular source of health care. Those who had a regular source of care were more likely to have continuity between routine and emergency care. Integration of health services with other agencies serving youth in shelters or on the street may improve access to care for those without a routine source of care and provide better continuity for these high-risk youth.

Angiotensin II increases vasopressin-stimulated facilitated urea permeability in rat terminal IMCDs

Angiotensin II receptors are present along the rat inner medullary collecting duct (IMCD), although their physiological role is unknown. Because urea is one of the major solutes transported across the terminal IMCD, we measured angiotensin II's effect on urea permeability. In the perfused rat terminal IMCD, angiotensin II had no effect on basal urea permeability but significantly increased vasopressin-stimulated urea permeability by 55%. Angiotensin II, both without and with vasopressin, also increased the amount of (32)P incorporated into urea transporter (UT)-A1 in inner medullary tissue exposed to these hormones ex vivo. Because angiotensin II activates protein kinase C, we tested the effect of staurosporine (SSP). In the absence of angiotensin II, SSP had no effect on vasopressin-stimulated urea permeability in the perfused terminal IMCD. However, SSP completely and reversibly blocked the angiotensin II-mediated increase in vasopressin-stimulated urea permeability. SSP and chelerythrine reduced the angiotensin II-stimulated (32)P incorporation into UT-A1 in inner medullary tissue exposed ex vivo. We conclude that angiotensin II increases vasopressin-stimulated facilitated urea permeability and (32)P incorporation into the 97- and 117-kDa UT-A1 proteins via a protein kinase C-mediated signaling pathway. These data suggest that angiotensin II augments vasopressin-stimulated facilitated urea transport in the rat terminal IMCD and may play a physiological role in the urinary concentrating mechanism by augmenting the maximal response to vasopressin.

Health-compromising behaviors: why do adolescents smoke or drink?: identifying underlying risk and protective factors

OBJECTIVES

To better understand the motivation for adolescent smoking and drinking and to identify the underlying risk and protective factors associated with these behaviors among adolescents.

DESIGN

Cross-sectional, school-based survey of students in grades 5 through 12.

PARTICIPANTS

A nationally representative sample of 2574 boys and 2939 girls in grades 7 through 12 from 297 public, private, and parochial schools across the United States who participated in The Commonwealth Fund Survey of the Health of Adolescent Girls and Boys in 1997.

MAIN OUTCOME MEASURES

Sex-specific adjusted relative risks (RRs) and 95% confidence intervals (CIs) comparing self-reported regular smokers and regular drinkers by risk and protective factors with adolescents reporting none of these behaviors.

RESULTS

Adolescent boys and girls were equally likely to be regular smokers (11.2%). The prevalence rate of regular drinking was only slightly higher for boys (22.4%) than it was for girls (19.3%). The rates of both health-risk behaviors were significantly higher for those reporting risk factors, and the strengths of associations varied by sex. Sex differences also emerged in motivation for engaging in these behaviors. When we adjusted for demographic characteristics, exposure to childhood abuse (RR, 4.1; 95% CI, 2.4-7.0) and stressful life events (RR, 2.4; 95% CI, 1.1-5.4) were strongly associated with increased risk for boys' regular smoking. Similar associations were found for regular drinking. For girls, a history of abuse (RR, 1.8; 95% CI, 1.1-2.8), violence within the family (RR, 2.2; 95% CI, 1.6-3.2), depressive symptoms (RR, 1.6; 95% CI, 1.0-2.4), and stressful life events (RR, 3.1; 95% CI, 1.8-5.6) were significantly associated with increased risk for regular smoking. Similar associations were again found for regular drinking. Parental support was protective against both health-risk behaviors for both sexes. Participation in extracurricular activities was associated with lower risk for regular smoking for boys (RR, 0.4; 95% CI, 0.2-0.7) and for girls (RR, 0.3; 95% CI, 0.2-0.5); however, there was no significant association between drinking behavior and participation in activities.

CONCLUSIONS

The increased risk for regular smoking and regular drinking among adolescents with a history of abuse, family violence, depressive symptoms, and stressful life events suggests that routine screening for abuse, violence, and other family experiences should be an essential component of adolescent health care visits. Effective prevention programs to reduce smoking and drinking among adolescents should recognize that health-risk behaviors may be associated with other negative life experiences and that the strength of these associations differs by sex.

Effects of Informal Cooperative Learning and the Affiliation Motive on Achievement, Attitude, and Student Interactions

The purpose of this study was to investigate the effect of informal cooperative learning and the affiliation motive on achievement, attitude, and student interactions. Participants classified as high or low need for affiliation used either an informal cooperative learning strategy or an individual strategy while receiving information, examples, practice and feedback from an instructional television lesson. Results indicated that participants who used the individual strategy acquired significantly more knowledge from the lesson and indicated significantly more continuing motivation for working alone than those who used the informal cooperative strategy. Instructional strategy did not influence performance on the application portion of the test. Results also revealed that high affiliation participants expressed significantly more continuing motivation than low affiliation participants for working with another person. Low affiliation participants expressed significantly more continuing motivation than high affiliation participants for working alone. Finally, results indicated that high affiliation dyads exhibited significantly more on-task group behaviors (taking turns, sharing materials, group discussion of content) and significantly more off-task behaviors than low affiliation dyads. Copyright 2000 Academic Press.

Adolescents who use the emergency department as their usual source of care

OBJECTIVE

To examine the factors associated with use of the emergency department (ED) as the only source of health care among adolescents.

DESIGN

Analyses of the 1997 Commonwealth Fund Survey of the Health of Adolescent Girls, a nationally representative sample of 6748 in-school male and female adolescents in 5th through 12th grade. The X2 statistics and logistic regression analyses were computed with the use of SUDAAN.

RESULTS

Overall, 4.6% of the adolescents in the survey, or 1.5 million adolescents in the United States, reported that the ED was their usual source of health care. In multivariate models, factors associated with the use of the ED included male sex, African American ethnicity, fewer financial resources, and living in a rural area. Adolescents with higher levels of risky behaviors, a history of physical or sexual abuse, and higher depression scores were all more likely to use the ED as their usual source of care. Adolescents who reported using the ED as their usual care source were also less likely to have had regular well visits and were more likely to report having missed needed care than those with other sources of primary care.

CONCLUSIONS

Adolescents who use the ED as their usual source of care are often from vulnerable populations. Many have special mental or physical needs that are unlikely to be met with ED visits only, and they are likely to have missed care they needed. Creating linkages between EDs and other services could help at-risk adolescents identify and use more appropriate sources of primary care.

Effect of age and testosterone on the vasopressin and aquaporin responses to dehydration in Fischer 344/Brown-Norway F1 rats

To determine if the aging-associated decline in testosterone results in attenuated vasopressin (VP) responses to dehydration, testosterone implants were given to aged male Fischer 344Brown-Norway F1(F344BNF1) rats. Water deprivation caused comparable dehydration, increased plasma VP (pVP), and decreased posterior pituitary (PP) VP content in 4-, 15-, and 28-month-old rats. Dehydration increased VP mRNA content of supraoptic nuclei only at 4 months, whereas VP mRNA length was increased at both 4 and 15 months of age. The elevated pVP in the water-deprived aged rats indicates that even without an increase in VP mRNA content, PP VP storage was adequate to maintain elevated pVP. Dehydration increased aquaporin-2 content at 4, but not at 15 or 28 months of age, suggesting decreased renal responsiveness to VP. Testosterone replacement did not produce dehydration-induced increases in VP mRNA or aquaporin-2. Therefore, testosterone deficiency does not result in altered VP responses to dehydration in aged F344BNF1 rats.

Long-term cognitive effects of Lyme disease in children

Most studies of adults infected with Lyme disease (LD) have found adverse cognitive effects from the disease. In contrast, the only controlled study investigating cognitive effects of LD in a pediatric population found no effects after a 2-year follow-up. However, it was questioned whether the negative effects might take longer than 2 years to emerge. Therefore, this investigation reports a 4-year follow-up of the original sample. Twenty-five children with strictly defined LD were compared with 17 sibling control children. A neuropsychological battery was utilized, including assessment of the cognitive areas of IQ, information processing speed, fine-motor dexterity, novel problem solving and executive functioning, short-term and intermediate memory, and acquisition of new learning. In addition, parents' subjective ratings were obtained on the disease's impact on their child's participation in everyday activities. No between-group differences were found for 17 of the 18 neuropsychological test measures, nor were there differences in parents' subjective ratings. Therefore, in contrast with studies of adults with LD, the results of long-term follow-up of the pediatric population continue to strongly support the finding that children treated appropriately for LD have an excellent prognosis for normal cognitive functioning.

UT-A urea transporter protein expressed in liver: upregulation by uremia

In perfused rat liver, there is phloretin-inhibitable urea efflux, but whether it is mediated by the kidney UT-A urea transporter family is unknown. To determine whether cultured HepG2 cells transport urea, thiourea influx was measured. HepG2 cells had a thiourea influx rate of 1739 +/- 156 nmol/g protein per min; influx was inhibited 46% by phloretin and 32% by thionicotinamide. Western analysis of HepG2 cell lysate using an antibody to UT-A1, UT-A2, and UT-A4 revealed two protein bands: 49 and 36 kD. The same bands were detected in cultured rat hepatocytes, freshly isolated rat hepatocytes, and in liver from rat, mouse, and chimpanzee. Both bands were present when analyzed by native gel electrophoresis, and deglycosylation of rat liver lysate had no effect on either band. Differential centrifugation of rat liver lysate showed that the 49-kD protein is in the membrane fraction and the 36-kD protein is in the cytoplasm. To determine whether the abundance of these UT-A proteins varies in vivo, rats were made uremic by 5/6 nephrectomy. The 49-kD protein was significantly increased 5.5-fold in livers from uremic rats compared to pair-fed control rats. It is concluded that phloretin-inhibitable urea flux in liver may occur via a 49-kD protein that is specifically detected by a UT-A antibody. Uremia increases the abundance of this 49-kD UT-A protein in rat liver in vivo.

Antibiotic susceptibilities of group C and group G streptococci isolated from patients with invasive infections: evidence of vancomycin tolerance among group G serotypes

A retrospective review of medical records for 32 patients with invasive group C streptococcus (GCS) or group G streptococcus (GGS) infections was performed. MICs and minimum bactericidal concentrations (MBCs) of penicillin, erythromycin, and vancomycin for all isolates were obtained. Tolerance of vancomycin, defined as an MBC 32 or more times higher than the MIC, was exhibited by 18 GGS isolates (54%). The identification of tolerance in clinical isolates of GGS and GCS may have clinical implications in treating these seriously ill patients.

JNK is a volume-sensitive kinase that phosphorylates the Na-K-2Cl cotransporter in vitro

Cell shrinkage phosphorylates and activates the Na-K-2Cl cotransporter (NKCC1), indicating the presence of a volume-sensitive protein kinase. To identify this kinase, extracts of normal and shrunken aortic endothelial cells were screened for phosphorylation of NKCC1 fusion proteins in an in-the-gel kinase assay. Hypertonic shrinkage activated a 46-kDa kinase that phosphorylated an NH2-terminal fusion protein, with weaker phosphorylation of a COOH-terminal fusion protein. This cytosolic kinase was activated by both hypertonic and isosmotic shrinkage, indicating regulation by cell volume rather than osmolarity. Subsequent studies identified this kinase as c-Jun NH2-terminal kinase (JNK). Immunoblotting revealed increased JNK activity in shrunken cells; there was volume-sensitive phosphorylation of NH2-terminal c-Jun fusion protein; immunoprecipitation of JNK from shrunken cells but not normal cells phosphorylated NKCC1 in gel kinase assays; and treatment of cells with tumor necrosis factor, a known activator of JNK, mimicked the effect of hypertonicity. We conclude that JNK is a volume-sensitive kinase in endothelial cells that phosphorylates NKCC1 in vitro. This is the first demonstration of a volume-sensitive protein kinase capable of phosphorylating a volume-regulatory transporter.

Access to medical care for adolescents: results from the 1997 Commonwealth Fund Survey of the Health of Adolescent Girls

PURPOSE

This study examined the factors associated with access to care among adolescents, including gender, insurance coverage, and having a regular source of health care.

METHODS

Analyses were done on the 1997 Commonwealth Fund Survey of the Health of Adolescent Girls, a nationally representative sample of in-school adolescents in 5th through 12th grade. Access to health care, missing needed care, and whether the adolescent had private time with their provider were assessed. Cochran-Mantel-Haenszel chi-square statistics were computed using SUDAAN.

RESULTS

Nearly a third of the 6748 adolescents surveyed had missed needed care. The most common reason for missing care was not wanting a parent to know (35%). Girls were more likely than boys to miss care (29% vs. 24%). Most adolescents reported using a source of primary health care (92%); girls were more likely than boys to use a physician's office rather than another site (65% vs. 60%). Eleven percent of adolescents reported having no health insurance. Uninsured adolescents were more likely to have missed needed care (46% vs. 25%) [corrected].

CONCLUSIONS

Certain groups of adolescents have less access to health care. Girls have more emotional barriers, such as not wanting parents to know about care, and embarrassment. Adolescents without health insurance are at high risk for missing care because of financial strain. States, insurers, and advocates can influence policies around confidentiality and insurance coverage to address these issues.

Adolescent girls' and boys' preferences for provider gender and confidentiality in their health care

PURPOSE

To assess the influence of demographic variables and health risk status on adolescents' preferences and actual receipt of services regarding provider gender, sharing a physician with parents, and private examinations.

METHODS

Data from students participating in the Commonwealth Fund 1997 Survey of the Health of Adolescent Girls were analyzed. The weighted sample included 6748 students from grades 5-12. The influence of demographic variables and health risk status on preferences regarding physician gender, sharing a physician with parents, and parental presence during examinations and on actual physician gender, sharing a physician with parents, and receipt of confidential care was assessed for the 5067 students who indicated that they had a health check-up or physical examination within the past 2 years. Associations were examined using SAS to determine preliminary estimates of significance and correlation coefficients, and SUDAAN to generate proportions and Cochran Mantel-Haenszel Chi-squared values. A multiple logistic regression procedure in SUDAAN was used to assess interaction among demographic variables.

RESULTS

Gender, race/ethnicity, grade level, and risk status were associated with preferences regarding provider gender and sharing a physician with parents. 50% of girls preferred a female provider; 48% had no preference. 23% of boys preferred a male provider; 65% had no preference. Most adolescents had no preference regarding whether they shared a physician with parents. Gender, race/ethnicity, grade level, and risk status were associated with preference regarding parental presence during examinations. Most younger girls preferred to have a parent present; most younger boys had no preference. Most older girls and boys preferred private examinations. For actual care situation, most adolescents were cared for by male health providers and did not share a physician with parents. 57% of girls and 66% of boys spoke privately with their health provider. Girls who had a female physician were more likely to have private time than were girls receiving care from a male physician. Gender, grade level, and risk status were associated with having private time with a physician.

CONCLUSIONS

Gender was a significant variable in adolescents' preferences regarding health care. Preferences were also influenced by race/ethnicity, grade level, and risk status. A substantial proportion of adolescents, including those involved in health risk activities, report not having private time with their health provider.

Heat shock proteins 70 and 90 increase calcineurin activity in vitro through calmodulin-dependent and independent mechanisms

We have shown that heat shock proteins (HSPs) associated with steroid receptor complexes are involved in the activation of calcineurin by aldosterone and dexamethasone. To determine whether HSPs directly interact with calcineurin, we measured the effect of HSPs 90, 70 and 56 on calcineurin activity in a cell-free, in vitro system using a calcineurin-specific substrate. HSP-90 (75 or 100 nM) significantly increased calcineurin V(max) in the presence of calmodulin, while maximal stimulation by HSP-70 occurred at 50 nM. Bovine serum albumin (BSA) and actin did not change basal calcineurin activity indicating that HSP-90 and HSP-70 specifically activate calcineurin. Neither HSP-70, HSP-56, nor ATP augmented HSP-90-induced activation of calcineurin. In the absence of calmodulin, HSP-90 restored calcineurin activity to basal levels while higher concentrations (333 and 500 nM) increased calcineurin activity. In contrast, HSP-70 failed to activate calcineurin activity in the absence of calmodulin. Immunoprecipitation of HSP-90 from in vitro mixtures as well as protein extracts from LLCPK-1 cells demonstrates that calcineurin co-precipitates with HSP-90. In summary: (1) HSP-90 and 70 stimulate calcineurin V(max) in vitro; (2) non-specific protein interactions do not activate calcineurin activity; (3) HSP-70 and HSP-56 do not enhance HSP-90-induced activation of calcineurin; (4) HSP-70 and HSP-90 activate calcineurin via a calmodulin-dependent and independent pathways; (5) Calcineurin co-precipitates with HSP-90 from LLCPK-1 cells as well as cell-free in vitro preparations.