Ectopic expression of serotonin-positive neurons in the hypothalamus associated with a significant serotonin decrease in the midbrain of food restricted rats

The effects of food restriction on the serotonergic system were investigated immunohistochemically in both the midbrain and hypothalamic regions of rats. Rats were fed on a restricted feeding schedule consisting of half of the ad libitum quantity for 1, 2, 4 and 6 weeks and a free feeding schedule for 1 week. The optical density of serotonin-positive neurons in the raphe nuclei of the midbrain was found to be significantly lower in the 1 week-food restricted group than in the ad libitum fed control. In the hypothalamus, serotonin-positive neurons were observed in the 1 and 2 week food restricted groups but not in the 4 and 6 week-food restricted groups. This finding was confirmed by immunohistochemistry with tryptophan hydroxylase, a serotonin synthesizing enzyme. In this study, we provide morphological evidence that food restriction has a significant effect on the serotonergic system of the midbrain and hypothalamic regions and suggest some possibilities for the ectopic expression of serotonin-positive neurons after food restriction.

Myocardial protection of immature rabbits with an ATP-sensitive K+ channel opener pinacidil

OBJECTIVE

To investigate the effectiveness of pinacidil, an opener of ATP-sensitive K+ channels, in protecting the myocardium of immature rabbit hearts from ischemic reperfusion injury.

METHODS

Rabbit hearts underwent 30 min of global normothermic ischemia followed by 30 min of reperfusion on the modified Langendorff apparatus. Fifty-two isolated hearts of 3-4 week-old immature rabbits were divided into 4 groups randomly. During ischemia, 3 different cardioplegic solutions were administered intermittently by infusion every 15 min (20-25 ml each time in all groups). Group 1: control group (n = 13); group 2: Krebs-Henseleit (K-H) solution with potassium (16 mmol/L) (n = 13); group 3: K-H solution with potassium (16 mmol/L) and pinacidil (50 mumol/L) (n = 13); group 4: K-H solution with potassium (16 mmol/L), pinacidil (50 mumol/L) and glibenclamide (10 mumol/L) (n = 13). The pre-ischemic and post-ischemic myocardial functions were assessed by the percentage recovery of the left ventricular developed pressure (LVDP); the left ventricular end-diastolic pressure (LVEDP); both the positive peak and negative peaks of the first derivative of the left ventricular pressures (+/- dp/dtmax); coronary flow; the level of creatine kinase (CK), lactic dehydrogenase (LDH) and aspartate transcarbamoylase (AST) in coronary sinus venous effluent; and by myocardial ultrastructural changes.

RESULTS

Before myocardial ischemia, there were no significant differences among the four groups in any of the parameters mentioned above. Post-ischemic recovery of LVDP, LVEDP, +/- dp/dtmax, coronary flow, the level of CK, LDH and AST, and myocardial ultrastructural changes were better in group 3 than those in the three other groups.

CONCLUSIONS

As a new and effective composition, pinacidil can significantly improve myocardial protection from cardioplegia for immature rabbit hearts.

Electroacupuncture-related changes of NADPH-diaphorase and neuronal nitric oxide synthase in the brainstem of spontaneously hypertensive rats

The aim of this study was to investigate the electroacupuncture-related changes of nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) and neuronal nitric oxide synthase (nNOS) in the brainstem of spontaneously hypertensive rats (SHR). We evaluated the changes of NADPH-d-positive neurons using a histochemical method and the changes of nNOS-positive neurons using an immunohistochemical method. The staining intensities of NADPH-d-positive neurons and nNOS-positive neurons were assessed in a quantitative fashion using a microdensitometrical method based on optical density by means of an image analyzer. The optical density of NADPH-d-positive neurons and nNOS-positive neurons of the Shinsu (BL23) and Choksamni (ST36) electroacupuncture groups were significantly decreased in most brainstem areas as compared to the normal and arbitrary groups, with the exception of the optical density of NADPH-d positive neurons in the prepositus nucleus as compared to the arbitrary group. The present results demonstrated that electroacupuncture changes the activity in the NO system in the brainstem of SHR and the site where electroacupuncture is administered is of importance for this effect.

[Treatment of pleural effusion caused by lung carcinoma with circular intrapleural hyperthermic perfusion and its mechanism]

OBJECTIVE

To assess the comprehensive effectiveness of intrapleural hyperthermic perfusion in treatment of malignant pleural effusion (MPE) caused by lung carcinoma and to explore its nechanism.

METHODS

45 patients with MPE caused by lung carcinoma underwent circular intrapleural hyperthermic perfusion with 43 warmed normal saline for 60 minutes. Response of pleural effusion and the original lung tumor, sife-effects, life qualty and survival time of the patients were followed up. Flow cytometry, optical microscopy, electron microscopy, and TUNEL method were used to compare the cytology and biochemistry of pleural effusion and cancer cells planted to the surface of pleura before and after the therapy.

RESULTS

The control rate of pleural effusion was 100% (CR 93.3%, PR 6.7%). No recurrence of pleural effusion was observed in 44 cases. Pleural effusion reoccured 12 months after the thermotherapy in one case. The time without pleural effusion lasted 16.5 months on average with the longest time of 40 months. CT performed one month after the thermotherapy in 13 cases showed that the primary focus in lung dwindled in 13 cases, and remained unchanged in 5 cases. Neither operative death nor post-operative complication was found. The life quality was improved in all the cases. The medium survival time was 16.8 months. One-year survival rate was 87%. One case survived more than 3 years, 4 cases survives more than 2 years (29, 30, 31, and 40 months respectively). Carcinoembryonic antigen decreased to normal and no carcinoma cell was found in pleural effusion. Flow cytometry showed that the tumor heteroploid peak diasappeared. Pyknosis and disintegration of nuclei, and apoptotic bodies of tumor cells planted on the surface of pleura were found by optical and electron microscopy. TUNEL showed apoptotic cells with brilliant yellow fluorescence.

CONCLUSION

(1) Circular intrapleural hyperthermic perfusion is a new, safe, and effective treatment for MPE. (2) Apoptosis-mediated cytocidal function, improvement of body immunity after hyperthermic perfusion and continuous wash of the perfusion fluid are important mechanisms of intrapleural hyperthermic perfusion in treatment of MPE caused by lung carcinoma.

A Phase I study of infusional vinblastine in combination with the P-glycoprotein antagonist PSC 833 (valspodar)

BACKGROUND

PSC 833 is a second-generation P-glycoprotein (Pgp) antagonist developed to reverse multidrug resistance (MDR). The authors conducted a Phase I study of orally administered PSC 833 in combination with vinblastine administered as a 5-day continuous infusion.

METHODS

Seventy-nine patients with advanced malignant disease were enrolled in the trial and treated with escalating doses of PSC 833. Pharmacokinetic interactions between PSC 833 and vinblastine were anticipated. Accordingly, when dose limiting toxicities were observed, the dose of vinblastine was reduced as PSC 833 was escalated. Three schedules and two formulations of PSC 833 were used in the study.

RESULTS

The maximum tolerated doses of PSC 833 were 12.5 mg/kg orally every 12 hours for 8 days for the liquid formulation in combination with 0.9 mg/m(2) per day vinblastine as a continuous intravenous infusion (CIV) for 5 days; and 4 mg/kg orally every 6 hours for 8 days for the microemulsion formulation in combination with 0.6 mg/m(2) per day vinblastine CIV for 5 days. The principal toxicities for PSC 833 were ataxia and paresthesias and for the combination, constipation, fever. and neutropenia. Increased oral bioavailability and increased peak and trough concentrations were observed with the microemulsion formulation. Significant interpatient variability in pharmacokinetic parameters was observed. Ten patients studied at the MTD for PSC 833 (4 mg/kg orally every 6 hours for 8 days) had inhibition of rhodamine efflux from CD56 positive peripheral lymphocytes as a surrogate for Pgp antagonism. Among 43 evaluable patients with clear cell carcinoma of the kidney, 3 patients had complete responses, and 1 patient had a partial response.

CONCLUSIONS

PSC 833 in combination with vinblastine can be administered safely to patients provided the vinblastine dose is adjusted for pharmacokinetic interactions. The high interpatient variability is a significant confounding factor. Surrogate studies with CD56 positive cells suggest that Pgp inhibition in the clinical setting is achievable. Improved methods for predicting pharmacokinetic interactions should improve future studies.

Inhibition of neuronal nitric oxide synthase enhances cell proliferation in the dentate gyrus of the adrenalectomized rat

Recent studies have demonstrated that the elimination of adrenal steroids by an adrenalectomy (ADX) increases the expression of neuronal nitric oxide synthase (NOS), and that it increases cell proliferation in the rat dentate gyrus. However, no evidence has been presented to date which indicates that NO regulates cell proliferation in the dentate gyrus of the adult rats. In this study, the effect of blocking NO production on ADX-induced increase of cell proliferation and serotonergic innervation was examined in the rat dentate gyrus. 7-nitroindazole (7-NI; 30 mg/kg, intraperitoneally), a selective inhibitor of neuronal NOS, was injected 1 day before an ADX and then once every 24 h for 4 days after the ADX subsequently. The proliferating cells were identified with 5-bromo-2-deoxyuridine (BrdU) immunostaining. Long-term inhibition of the neuronal NOS by 7-NI markedly increased the BrdU-labeled cell population density 4-18-fold in the dentate gyrus of the adrenalectomized rats compared to that in the vehicle-injected adrenalectomized rats. Immunoreactivity of serotonin, known as a mediator of granule cell genesis, was detected only in the dentate gyrus of 7-NI-injected adrenalectomized rats. These results indicate that NO may be involved in the cell proliferation in the dentate gyrus of the adrenalecomized rat and that serotonin may mediate the regulatory effect of NO on the cell proliferation in rat dentate gyrus.

Atomic size effects in continuum modeling

Continuum modeling of many physical systems typically assumes that the spatial extent of an atom is small compared to the quantities of interest and can therefore be neglected. We show that this is valid only asymptotically. For many applications of practical interest, the spatial extent of a discrete atom cannot be neglected. We have developed a model for the description of epitaxial growth based on the levelset method, and find that we can accurately predict quantities such as the island densities, if we implement boundary conditions in a region with atomic width, rather than just on a line without any spatial extent. Only in the limit of very large islands and island spacings can this be neglected.

Nd1, a novel murine Kelch family protein, may play the role of a housekeeping gene

The murine Nd1 gene encodes a novel Kelch family protein and expresses two forms of mRNA, long (Nd1-L) and short (Nd1-S), in various tissues. We characterized the genomic organization of the Nd1 gene, and found that Nd1-L and Nd1-S consist of 16 and nine exons respectively, and that exons I-VIII are shared between them. Three transcription initiation sites were identified in the 5'-flanking region and the most 3' side (+1) is likely to be a major one. Promoter analysis revealed that the region between positions -247 and -86 was sufficient for expression, and that two Sp1-binding sites and one NF-kappaB-binding site in the region were critical for promoter activity. Furthermore, the promoter region lacks a TATA and a CAAT box and has a highly GC-rich region with two important Sp1-binding sites. These characteristics of the Nd1 gene promoter are similar to the properties of housekeeping genes.

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.

Reliability and validity of the adolescent health profile-types

OBJECTIVES

The purpose of this study was to demonstrate the preliminary reliability and validity of a set 13 profiles of adolescent health that describe distinct patterns of health and health service requirements on four domains of health.

METHODS

Reliability and validity were tested in four ethnically diverse population samples of urban and rural youths aged 11 to 17-years-old in public schools (N = 4,066). The reliability of the classification procedure and construct validity were examined in terms of the predicted and actual distributions of age, gender, race, socioeconomic status, and family type. School achievement, medical conditions, and the proportion of youths with a psychiatric disorder also were examined as tests of construct validity.

RESULTS

The classification method was shown to produce consistent results across the four populations in terms of proportions of youths assigned with specific sociodemographic characteristics. Variations in health described by specific profiles showed expected relations to sociodemographic characteristics, family structure, school achievement, medical disorders, and psychiatric disorders.

CONCLUSIONS

This taxonomy of health profile-types appears to effectively describe a set of patterns that characterize adolescent health. The profile-types provide a unique and practical method for identifying subgroups having distinct needs for health services, with potential utility for health policy and planning. Such integrative reporting methods are critical for more effective utilization of health status instruments in health resource planning and policy development.

Prevalence of human foamy virus-related sequences in the Korean population

The possible association of human foamy virus (HFV) with human thyroid disorders such as Graves' disease (GD) has been a topic of controversy due to the inconsistent results reported by several groups of investigators. Here we report the investigation of the presence of HFV-related sequences in the Korean population. DNA was obtained from peripheral blood lymphocytes from 24 GD patients and 23 healthy blood donors and subjected to PCR amplification using three sets of nested primers derived from gag, env, and LTR regions of the HFV genome. Contrary to previously reported studies, our analysis identified HFV-related sequences in the genomes of both healthy individuals and the GD patients. However, the nature of the HFV genome present in each group appeared to be different. We detected all 3 regions of HFV-related sequences in 29% of the HFV-positive GD patients, while no samples in the control group amplified all three regions. This suggests that the LTR may be used as a tool for screening for HFV in GD patients. Our data favor the hypothesis of a relationship between GD and the presence of HFV-related sequences, though in a complex way.

Social role functioning by adolescents with psychiatric disorders

OBJECTIVE

To identify aspects of social role functioning that are impaired in adolescents with specific psychiatric disorders in order to improve the psychiatric taxonomy and clinical knowledge base.

METHOD

Adolescents in four urban public schools were screened for mental health problems. Structured psychiatric interviews (National Institute of Mental Health Diagnostic Interview Schedule for Children Version 2.2) with 288 adolescents and their mothers were used to identify youths with psychiatric disorders, and 10 aspects of social role functioning were assessed. Aspects of social role functioning that discriminated between youths with and without psychiatric disorders and between those with emotional disorders and those with disruptive disorders were identified for boys and for girls.

RESULTS

Boys with any type of disorder and all youths with disruptive disorders had significant, consistent impairment in academic performance and several other areas of functioning. Youths with emotional disorders, especially girls, demonstrated impairment in social activity participation and peer acceptance, but girls with disorders were not as consistently different from those without as were the boys with emotional disorders.

CONCLUSIONS

Role functioning differs in important ways between youths with and without psychiatric disorders and between girls and boys with disorders. The results underscore the importance of investigating observable aspects of role behavior in order to improve the timely detection and effective management of psychiatric disorders in youth.

Structural modification of an orally active thrombin inhibitor, LB30057: replacement of the D-pocket-binding naphthyl moiety

An amidrazonophenylalanine derivative LB30057 (2) was identified as a potent (Ki = 0.38 nM), selective, and orally active thrombin inhibitor. As a continuation of studies into benzamidrazone-based thrombin inhibitors, we have structurally modified compound 2 by replacing the naphthyl group with a variety of hydrophobic moieties. This study led to discovery of several compounds with significantly enhanced potency in thrombin inhibition without sacrificing selectivity against trypsin and oral absorption. The highest activity was obtained with compound 23 (Ki = 0.045 nM).

Ilio-psoas abscess in the paediatric population: treatment by US-guided percutaneous drainage

BACKGROUND

Image-guided percutaneous drainage has been shown to be a safe and effective alternative to surgery in the management of psoas abscess in adults and adolescents. There is little information on its use in children.

OBJECTIVE

To evaluate the safety and efficacy of US-guided percutaneous needle aspiration and catheter drainage of ilio-psoas abscesses.

MATERIALS AND METHODS

A retrospective review of 14 children with 16 ilio-psoas abscesses (10 pyogenic and 4 tuberculous) who were treated by US-guided percutaneous needle aspiration (n = 5) or catheter drainage (n = 9) along with appropriate antimicrobial therapy.

RESULTS

Percutaneous treatment was successful in 10 of the 14 patients; all showed clinical improvement within 24-48 h of drainage and subsequent imaging demonstrated resolution of the abscess cavities. Surgery was avoided in all of these ten patients except one, who underwent open surgical drainage of ipsilateral hip joint pus. Of the other four patients, two had to undergo surgical drainage of the ilio-psoas abscesses after failure of percutaneous treatment, one improved with antibiotics after needle aspiration failed to yield any pus, and one died of continuing staphylococcal septicaemia within 24 h of the procedure. There were no procedural complications.

CONCLUSIONS

Percutaneous drainage represents an effective alternative to surgical drainage as a supplement to medical therapy in the management of children with ilio-psoas abscesses.

Adolescents' knowledge of their health insurance coverage

PURPOSE

To determine the accuracy of adolescents' self-report of health insurance coverage, using parents' report as a comparison standard.

METHODS

Two separate samples of urban, school-based adolescents and their parents completed self-administered questionnaires about type of health insurance coverage. Sample 1 included 123 and Sample 2 included 93 adolescent-parent pairs. Percent agreement and the kappa statistic were determined for each of the sample groups, and for males versus females and older (> 14 years) versus younger (< or = 14 years) adolescents.

RESULTS

In Sample 1, 33% of adolescent respondents responded "don't know" to the question about type of insurance coverage, and 4% left the question blank; in Sample 2, 3% answered "don't know," with none leaving the question blank. For Sample 1, we found a 57% rate of agreement of adolescents with their parents, and a corresponding kappa of .21. Females and older subjects demonstrated greater accuracy, with kappa's all in the range .13-.29. In Sample 2, 73% of subjects agreed with parents' report, with a kappa of .48. Females and older subjects also demonstrated greater accuracy, with the highest kappa of .59 demonstrated by older females. Excluding those responding with "don't know," we found overall percent agreement with parents of 87% in Sample 1 and 73% in Sample 2; the corresponding kappas were .47 and .51. Females demonstrated higher agreement with parents in both samples. The results stratifying by age were inconsistent. In Sample 1, privately insured subjects were more accurate reporters than those either on medical assistance or uninsured. In Sample 2, no differences were seen by type of insurance.

CONCLUSIONS

Many adolescents do not know their health insurance coverage status. However, for those who did claim to know, acceptable rates of accuracy using both percent agreement and the kappa statistic were demonstrated. Further research is needed to determine how information about insurance is communicated to adolescents and how this knowledge affects access to and use of health services.

Satiation and masticatory function modulated by brain histamine in rats

Both the ventromedial hypothalamus (VMH) and the mesencephalic trigeminal sensory nucleus (Me5) are densely innervated by histaminergic neurons. The depletion of neuronal histamine (HA) from the Me5 by the bilateral microinfusion of 448 nmol/rat alpha-fluoromethylhistidine (FMH), a specific suicide inhibitor of histidine decarboxylase, reduced the eating speed and prolonged meal duration, while leaving the meal size unaffected. HA depletion from the VMH increased the size of the meal and prolonged its duration, but not the eating speed. When the HA turnover rate was measured at 15 min after the scheduled feeding following fasting for less than 24 hr, the rate increased in the region including the Me5, but not in the hypothalamus. The turnover rate reached higher levels at 60 min in both regions. Gastric intubation of an isocaloric liquid diet or an equivolume of water with the liquid diet abolished the increase in HA turnover both in the Me5 region and the hypothalamus. The present findings indicate that brain HA thus modulates satiation through both the VMH and masticatory function as well as due to the action of the Me5. The HA function activated by mastication began earlier in the Me5 and later in the hypothalamus due to a signal originating from the oral proprioceptors and initiated by chewing.

Evolution of magnetic and superconducting fluctuations with doping of high-Tc superconductors

Electronic Raman scattering from high- and low-energy excitations was studied as a function of temperature, extent of hole doping, and energy of the incident photons in Bi2Sr2CaCu2O8+/-delta superconductors. For underdoped superconductors, short-range antiferromagnetic (AF) correlations were found to persist with hole doping, and doped single holes were found to be incoherent in the AF environment. Above the superconducting (SC) transition temperature Tc, the system exhibited a sharp Raman resonance of B1g symmetry and energy of 75 millielectron-volts and a pseudogap for electron-hole excitations below 75 millielectron-volts, a manifestation of a partially coherent state forming from doped incoherent quasi particles. The occupancy of the coherent state increases with cooling until phase ordering at Tc produces a global SC state.

Autonomic and behavioral thermoregulation in guinea pigs during postnatal maturation

Serial experiments were carried out on seven chronically instrumented Hartley-strain guinea pigs at 1, 3, and 5 wk of age to define their autonomic and behavioral thermoregulatory profiles and to test the hypothesis that they have the mechanisms in place shortly after birth that allow them to optimize their energy expenditure for thermoregulation by selecting a thermal environment that requires the lowest metabolic oxygen requirements. Each animal was studied in both a thermocline to determine selected ambient temperature and in a metabolic chamber to determine the thermoregulatory response to forced changes in ambient temperature. In the thermocline, the guinea pigs at all postnatal ages selected an ambient temperature that placed core temperature, oxygen consumption, thermal conductance, heart rate, and respiratory rate at levels comparable to those observed at ambient temperatures in which minimal oxygen consumption occurred in the metabolic chamber. Thus our experiments provide evidence that guinea pigs have the neurophysiological mechanisms in place shortly after birth that allow them to optimize their energy expenditure for thermoregulation by selecting a thermal environment that corresponds to the lowest metabolic oxygen requirements.

Release of glutathione from erythrocytes and other markers of oxidative stress in carbon monoxide poisoning

Rats exposed to CO in a manner known to cause oxidative stress in brain exhibited a twofold increase in plasma levels of oxidized proteins, thiobarbituric acid-reactive substances (TBARS), oxidized glutathione (GSSG), and reduced glutathione (GSH). Changes were neither directly related to hypoxic stress from carboxyhemoglobin nor significantly influenced by circulating platelets or neutrophils. Treatment with the nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester inhibited elevations in GSH and GSSG but not changes in oxidized proteins or TBARS, suggesting that two oxidative mechanisms may be operating in this model and that GSH and GSSG elevations involved nitric oxide-derived oxidants. Elevations of blood GSH and GSSG occurred at different anatomic sites, indicating that no single organ was the source of the increased peptides. Animals that underwent exchange transfusion with a hemoglobin-containing saline solution did not exhibit elevations in GSH and GSSG, suggesting that blood-borne cells released these peptides in response to oxidative stress. In in vitro studies, erythrocytes, but not platelets and leukocytes, responded to oxidative stress from peroxynitrite by releasing GSH, whereas no release was observed in response to nitric oxide or superoxide. Glucose, maltose, and cytochalasin B, agents that protect extracellular components of the hexose transport protein complex from oxidative stress, prevented GSH release. The data indicate that nitric oxide-derived oxidants are involved in CO-mediated oxidative stress within the vascular compartment and that elevations of several compounds may be useful for identifying exposures to CO likely to precipitate brain injury.

Ki-67, p53, and Bcl-2 expression of serrated adenomas of the colon

To investigate epithelial cell proliferation and oncoprotein expression of the serrated adenoma, a term that has been used synonymously with mixed hyperplastic and adenomatous polyp, immunohistochemical staining using polyclonal antibodies against Ki-67 and p53, and a Bcl-2 monoclonal antibody, was performed and the results compared with those in hyperplastic polyps and tubular adenomas. A total of 20 serrated adenomas all characterized by a serrated glandular pattern, contained immature goblet cells, upper crypt zone mitotic figures, and a few nucleoli within the epithelial cells. Twenty hyperplastic polyps and 20 tubular adenomas (all with low-grade dysplasia) were examined, and lesions that contained separate areas of hyperplastic and adenomatous glands were excluded. The Ki-67-positive rate in the middle zone of the crypts in serrated adenomas was significantly higher than in hyperplastic polyps but lower than in tubular adenomas; a similar tendency was also noted for the upper zone. Both serrated adenomas and hyperplastic polyps demonstrated Bcl-2-positive reactivity that was essentially limited to the lower crypt zone, while in contrast, involvement in tubular adenomas often extended to the middle zone. No p53 overexpression was found in any category. These results suggest that serrated adenomas may be committed to independent growth.

The impact of asthma on the health status of adolescents

OBJECTIVE

To identify a characteristic pattern of health and illness for adolescents with asthma, we compared the health status of teenagers with asthma to those without asthma using a recently developed generic health status instrument, the Child Health and Illness Profile, Adolescent Edition (CHIP-AE).

METHODS

This was a cross-sectional survey using a school sample of 3109 teenagers. Participants completed the CHIP-AE during school in northern Baltimore City, rural western Maryland, and rural Arkansas. The health and functioning scores of teens without asthma ("well" group) were compared with those with asthma with and without recent wheezing.

RESULTS

Of the 12% who reported that a physician had ever told them they had asthma, 50% had problems with wheezing in the past 28 days. Compared with well teenagers, those with asthma and recent wheezing had lower perceived well-being, more physical and emotional symptoms, greater limitations in activity, more comorbidities, and more negative behaviors that threaten social development. These findings held true in multivariable regression models that controlled for sociodemographics and sites of data collection. Teenagers with asthma without recent wheezing reported a greater number of comorbidities than well teens and showed similar trends in health status as those with recently symptomatic asthma.

CONCLUSIONS

Multiple aspects of adolescent health status are affected by asthma, particularly if it is recently symptomatic. These results argue for incorporating a generic health status instrument, such as the CHIP-AE, in studies that document the health needs or outcomes of medical care for populations of teenagers with asthma.

Percutaneous transluminal balloon pulmonary valvuloplasty using domestic balloon catheter for congenital pulmonary valve stenosis in children

OBJECTIVE

To estimate the effect of percutaneous balloon pulmonary valvuloplasty (PBPV) using domestic balloon catheter for congenital pulmonary valve stenosis (PVS) in infants and children.

PATIENTS AND METHODS

The data of 70 patients aged from 1.5 to 12 years (mean 5.5 +/- 3.4 years) who underwent PBPV using domestic balloon catheter for PVS in our institution were reviewed. Sixty-six patients had dome-shaped valve stenosis, and 4 had displastic valve stenosis. SaO2 reduced in 5 patients and associated open foramen ovale was noted in 23. Predilatation, right ventricular systolic pressure ranged from 60 to 234 mmHg (mean 115.75 +/- 36.15 mmHg). The systolic gradient (delta P) from right ventricle to pulmonary artery was 89.92 +/- 38.25 mmHg. Balloon diameter was selected 120%-142% of pulmonary valve annulus diameter (mean 132%). All patients were followed up for 3 months-4 years by means of clinical examination. ECG, 2D-UCG, and Doppler-UCG.

RESULTS

After dilatation, delta P reduced from 89.92 +/- 38.25 to 14.65 +/- 11.40 mmHg (P < 0.001). The rate of decrease in transvalve gradient (delta P) was 83.7%. No patients experienced procedure-related events. Mid-term follow-up showed that no patients had clinical and instrumental complications. Doppler and ECG analyses showed that delta P did not change significantly similar to immediate gradient after PBPV and right ventricular hypertrophy disappeared progressively 6 months after PBPV.

CONCLUSIONS

PBPV is a useful, safe and definitive procedure in the treatment of isolated PVS in infants and children. The properties and features of the balloon catheter produced by Shanghai Med-Tech Factory are similar to those of Med-Tech balloon catheter of U.S.A.

Stability and folding of precursor and mature tryptophan-substituted ribose binding protein of Escherichia coli

A mutant ribose binding protein (RBP) of Escherichia coli was obtained by site-directed mutagenesis, replacing Phe-187 in the wild-type RBP (WT-RBP) with a Trp residue, in order to compare its stability and folding behavior with those of the WT-RBP. The equilibrium unfolding properties and the folding kinetics of these proteins were monitored by fluorescence and circular dichroism (CD). For both WT-RBP and the Trp-substituted RBP (Trp-RBP), the conformational stabilities of the precursor proteins and the mature proteins were the same, indicating that the signal peptide had no influence on the property of the mature domain. The Phe/Trp substitution in the mature domain, however, brought about a significant decrease in the conformational stability. The signal peptide had an appreciable retarding effect on the folding of the precursor Trp-RBP as was reported for the WT-RBP. Refolding kinetics of the WT-RBP and Trp-RBP showed a two-step reaction when monitored by fluorescence and by CD.

Persistent reduction of GABA(A) receptor-mediated inhibition in rat hippocampus after chronic intermittent ethanol treatment

GABA(A) receptor-mediated function was studied in rats treated with chronic intermittent ethanol (CIE). Rats were given 60 doses of 6g/kg ethanol every 24 h by gastric intubation, with repeated intoxicating and withdrawal episodes leading to a kindling-like increase in seizure susceptibility (Kokka et al., Alcohol: Clin. Exp. Res., 17 (1993) 525-531). Efflux of 36Cl-, evoked by application of muscimol, a measure of GABA(A) receptor function, was examined in 300 mu m slices obtained from frontal, parietal, and temporal cortex, hippocampus, and inferior colliculus, one day after the last administration of ethanol. Compared to controls, the 36Cl- efflux in hippocampal slices of CIE rats was significantly reduced by 29%, while there were no changes in the other brain regions studied. In hippocampal slices, paired-pulse inhibition in CA1 pyramidal neurons, measured extracellularly using homosynaptic orthodromic stimulation at an interval of 10 ms, was significantly reduced in CIE rats. A significant decrease by 40% both at 2 and 40 days after 60 doses of ethanol was found, implying a persistent decrease in GABA(A) receptor-mediated inhibition in CIE rats. These reductions in paired-pulse inhibition are consistent with the decrease in the pentylenetetrazol (PTZ) seizure threshold which was previously observed in CIE rats. Therefore, we suggest that this reduction of GABA(A) receptor-mediated inhibition contributes to the persistent increase in seizure susceptibility of CIE rats.