Nasopharyngeal carcinoma with leptomeningeal dissemination: case report

Nasopharyngeal carcinoma (NPC) is a highly prevalent malignancy in southeast China, Hong Kong, and Taiwan. Spread of this tumor is known to occur via three main routes, i.e., local invasion of adjacent structures, regional metastasis to neck nodes, and hematogenous metastasis to distant organs. In this report, we describe a rare case of NPC disseminated via the leptomeninges, so called meningeal carcinomatosis (MC). The patient was a 62 year-old man who presented with multiple cranial nerve palsies and a headache, and was diagnosed with NPC in August 1988. The primary tumor regressed completely after induction chemotherapy and radiation therapy. Computerized tomography (CT) 17 months after radiation therapy showed multiple enhanced nodules scattered along the temporal meninges. The nodules increased in number and size in the subsequent CT scan 4 months later. The patient declined further invasive procedures and oncologic treatments, and he expired at home 9 months after the development of MC. It is speculated that perineural invasion and access to the subarachnoid space was the major cause of MC in this case. The case, although rare, possibly highlights a rare route of tumor dissemination in NPC.

Alfentanil for intubation under halothane anaesthesia in children

Intubating conditions under halothane anaesthesia aided with alfentanil 20 micrograms.kg-1 were compared with suxamethonium 2 mg.kg-1 in 40 children presenting for day dental procedures. The condition of vocal cords, jaw relaxation and presence of movement and coughing were scored to give the overall intubating conditions. Successful intubation was achieved in 100% of the suxamethonium group and 94.7% of the alfentanil group. The cardiovascular response to intubation was attenuated in the alfentanil group. Some 43.7% of those receiving suxamethonium developed myalgia the day after surgery compared with 0% in the alfentanil group (P < 0.01).

Preparation of Shell-Core Cu(2)O-Cu Nanocomposite Particles and Cu Nanoparticles in a New Microemulsion System

Shell-core Cu(2)O-Cu nanocomposite particles and metal Cu nanoparticles are synthesized in a new microemulsion system which consists of saturated Cu(2+) salt aqueous solution dispersed in isopropanol and stabilized by polyvinylalcohol (PVA). The size of the composite particles and the thickness of the Cu(2)O shell layer can be controlled by the volume ratio of isopropanol to H(2)O (the ratio is defined as R). When R >/= 1000, it is available to obtain metal Cu nanoparticles. Copyright 1999 Academic Press.

Autofluorescence spectroscopic differentiation between normal and cancerous colorectal tissues by means of a two-peak ratio algorithm

We conducted an ex vivo study with light-induced autofluorescence spectroscopy to distinguish between normal and cancerous colorectal tissues. A total of 20 normal and 20 cancerous tissue samples were obtained from 20 patients undergoing oncologic surgery of the colon and rectum. The tissue diagnosis was confirmed histologically. After excitation, the autofluorescence spectra of each sample were measured and recorded. To determine the most appropriate excitation wavelength, we analyzed the autofluorescence spectra at excitation wavelengths of 280 to 400 nm, in 10-nm increments. To distinguish between normal and cancerous tissues, we first calculated the "two-peak ratio" (the ratio of the integrated intensity of the first peak +/- 6 nm to the integrated intensity of the second peak +/- 6 nm) of the autofluorescence spectra. By applying receiver operating characteristic (ROC) curves and calculating the areas under the ROC curves (AUC), we found 330 and 340 nm to be the most appropriate excitation wavelengths to distinguish between cancerous and normal colorectal tissue. When approximate thresholds were selected, autofluorescence spectroscopy with 330 nm excitation yielded a sensitivity of 85%, a specificity of 90%, and a positive predictive value of 89% for detection of cancerous tissue. The ex vivo autofluorescence study and two-peak ratio algorithm developed herein may be very useful for developing an algorithm for in vivo diagnosis of colorectal cancer.

Genotoxic effects of heterocyclic aromatic amines in human derived hepatoma (HepG2) cells

In order to study the mutagenic effects of heterocyclic aromatic amines (HAAs) in cells of human origin, five compounds, namely 2-amino-3-methyl-imidazo[4,5-f]quinoline (IQ), 2-amino-3, 4-dimethyl-imidazo[4,5-f]quinoline (MeIQ), 2-amino-3, 8-dimethyl-imidazo[4,5-f]quinoxaline (MeIQx), the pyridoimidazo derivative 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), were tested in micronucleus (MN) assays with a human derived hepatoma (HepG2) cell line. All HAAs caused significant, dose-dependent effects. The activities of IQ, MeIQ, MeIQx and PhIP were similar (lowest effective concentrations 25-50 microM), whereas Trp-P-1 was effective at a dose of >/=2.1 microM. In addition, the HAAs were tested in MN assays with Chinese hamster ovary (CHO) cells and in Salmonella strain YG1024 using HepG2 cell homogenates as an activation mix. In the CHO experiments, positive results were obtained with Trp-P-1 and PhIP, whereas the other compounds were devoid of activity under all experimental conditions. The discrepancy in the responsivity of the two cell lines is probably due to differences in their acetylation capacity: enzyme measurements with 2-aminofluorene as a substrate revealed that the cytosolic acetyltransferase activity in the HepG2 cells is approximately 40-fold higher than that of the CHO cells. In the bacterial assays all five HAAs gave positive results but the ranking order was completely different from that seen in the HepG2/MN experiments (IQ > MeIQ > Trp-P-1 >/= MeIQx >> PhIP) and the mutagenic potencies of the various compounds varied over several orders of magnitude. The order obtained in bacterial tests with rat liver S9 mix was more or less identical to that seen in the tests with HepG2 cell homogenates but the concentrations of the amines required to give positive results were in general substantially lower (10(-5)-10(-1) microM). Overall, the results of the present study indicate that MN/HepG2 tests might reflect the mutagenic effects of HAAs more adequately than other in vitro mammalian cell systems due to the presence of enzymes involved in the metabolic conversion of the amines.

Expression and alternative splicing of the mouse autoimmune regulator gene (Aire)

AIRE, the gene responsible for the autoimmune polyglandular syndrome type 1 (APS1) or APECED, may act as a transcription factor according to its predicated protein structure. Here we demonstrate the low expression level of the mouse Aire gene as it is undetectable by Northern blot analyses. However, RT-PCR analyses revealed expression of Aire in mouse thymus, ovary, lung, testis, kidney and adrenal gland. Barely detectable level of RT-PCR product was also found in thyroid gland and heart but no amplification was detected in pancreas, spleen and liver. Competitive RT-PCR assays demonstrated highest expression level of Aire mRNA in thymus. In addition to the complete cDNA (Aire or Aire-1a), we identified 11 alternative splicing forms (designated as Aire-1b, Aire-1c, Aire-1d, Aire-2a, Aire-2b, Aire-2c, Aire-2d, Aire-3a, Aire-3b, Aire-3c and Aire-3d). These forms result from combinations of four alternative splicing units (exon 10, exon 11, 12 bp in exon 6 and 3 bp in exon 8). The relative abundance of these splicing forms was also determined.

Removal of cardiac beat artifact in oesophageal pressure measurement by frequency analysis

Oesophageal pressure (Pes) measurements are important in medical research and useful in clinical diagnosis. Measurements, however, are contaminated heavily by cardiac artifacts. The spectrum and waveform of the Pes signal is obtained from the oesophageal balloon. Adaptive finite impulse response (AFIR) filter and modified adaptive noise cancellation (MANC) methods are adopted to filter out cardiac beat interference. These results are compared. In the frequency domain, frequency variations and spectral overlap between the Pes components and cardiac beat signal components impact on the performance of the filter. From our experimental results on power strength, the fourth or higher harmonics did not have any significant effect on the filter performance. However, the second harmonics of these signals had a significant effect on the filtering result. Thus, in the design of AFIR filters, attention is needed to minimise these effects. In frequency analysis, these harmonics or overlapping frequencies do not affect MANC. MANC was the better method for eliminating cardiac beat artifact in Pes measurement. The dynamic compliance (Cdyn) was also used to evaluate the performance of MANC and AFIR. The standard deviation of Cdyn was less than 0.15 using MANC, compared with standard deviations as high as 0.57 for AFIR. We conclude that MANC performs better than AFIR.

Evaluation of a selective screening for colorectal carcinoma: the Taiwan Multicenter Cancer Screening (TAMCAS) project

BACKGROUND

Although the efficacy of mass screening for colorectal carcinoma (CRC) with a fecal occult blood test has been demonstrated in several randomized trials, a mass screening approach used in countries with intermediate or low incidence of CRC might be costly. Screening high risk people may be an alternative approach, to aid in the prevention of death from CRC. However, the efficacy of CRC screening for high risk people in such countries is uncertain.

METHODS

For this study, a multicenter design was devised to identify high risk groups without clinical symptoms related to CRC; these subjects were identified through the study of index cases of CRC in Taiwan. Colonoscopy, in combination with a fecal occult blood test or double-contrast barium enema, was used to screen high risk groups. A total of 8909 subjects were invited to attend screening. Of 8909, 81 with asymptomatic CRC were detected in one-shot screening. Markov models, in conjunction with a simulated approach, were proposed to estimate relevant parameters in relation to disease progression and to assess the effect of the interval between screenings on the efficacy of CRC screening for these high risk groups.

RESULTS

The estimated preclinical incidence rate was 0. 00396 (95% confidence interval [CI], 0.002944-0.004985), which was 21 times that reported from a cancer registry in 1994. The simultaneous estimations of mean sojourn time (the average duration between the preclinical screen-detectable phase and the clinical phase) and sensitivity were 2.8 years (95% CI, 2.15-4.30) and 95.0% (95% CI, 24.4-99.9%), respectively. Predictions of mortality reduction for people who received annual, biennial, and triennial screening regimes compared with controls were 26% (95% CI, 0-50%), 23% (95% CI, 0-48%), and 21% (95% CI, 0-47%), respectively.

CONCLUSIONS

The efficacy of selective colorectal carcinoma screening has been demonstrated in this study. A high preclinical CRC incidence rate also suggests that such a screening strategy might be cost-effective for countries with intermediate or low incidence of CRC. Methods proposed in this study can be used to evaluate the efficacy of CRC screening in similar screening trials.

Transposition of the endogenous insertion sequence element IS1126 modulates gingipain expression in Porphyromonas gingivalis

We have previously reported on a Tn4351-generated mutant of Porphyromonas gingivalis (MSM-3) which expresses enhanced arginine-specific proteinase activity and does not utilize hemin or hemoglobin for growth (C. A. Genco et al., Infect. Immun. 63:2459-2466, 1995). In the process of characterizing the genetic lesion in P. gingivalis MSM-3, we have determined that the endogenous P. gingivalis insertion sequence element IS1126 is capable of transposition within P. gingivalis. We have also determined that IS1126 transposition modulates the transcription of the genes encoding the lysine-specific proteinase, gingipain K (kgp) and the arginine-specific proteinase, gingipain R2 (rgpB). Sequence analysis of P. gingivalis MSM-3 revealed that Tn4351 had inserted 60 bp upstream of the P. gingivalis endogenous IS element IS1126. Furthermore, P. gingivalis MSM-3 exhibited two additional copies of IS1126 compared to the parental strain A7436. Examination of the first additional IS1126 element, IS1126(1), indicated that it has inserted into the putative promoter region of the P. gingivalis kgp gene. Analysis of total RNA extracted from P. gingivalis MSM-3 demonstrated no detectable kgp transcript; likewise, P. gingivalis MSM-3 was devoid of lysine-specific proteinase activity. The increased arginine-specific proteinase activity exhibited by P. gingivalis MSM-3 was demonstrated to correlate with an increase in the rgpA and rgpB transcripts. The second additional IS1126 element, IS1126(2), was found to have inserted upstream of a newly identified gene, hmuR, which exhibits homology to a number of TonB-dependent genes involved in hemin and iron acquisition. Analysis of total RNA from P. gingivalis MSM-3 demonstrated that hmuR is transcribed, indicating that the insertion of IS1126 had not produced a polar effect on hmuR transcription. The hemin-hemoglobin defect in P. gingivalis MSM-3 is proposed to result from the inactivation of Kgp, which has recently been demonstrated to function in hemoglobin binding. Taken together, the results presented here demonstrate that the introduction of Tn4351 into the P. gingivalis chromosome has resulted in two previously undocumented phenomena in P. gingivalis: (i) the transposition of the endogenous insertion sequence element IS1126 and (ii) the modulation of gingipain transcription and translation as a result of IS1126 transposition.

Membranous glomerulonephritis induced in the pig by antibody to angiotensin-converting enzyme: considerations on its relevance to the pathogenesis of human idiopathic membranous glomerulonephritis

In the course of studies on the humoral consequences of swine to primate xenotransplantation, the investigators induced formation of glomerular subepithelial immune deposits and tubular lesions in pigs injected with heterologous antibody to angiotensin-converting enzyme. This study describes the morphology of the lesions, discusses their mechanism, explains their relevance for understanding the pathogenesis of human idiopathic membranous glomerulonephritis, and proposes future directions for investigations.

NF-kappaB induces expression of the Bcl-2 homologue A1/Bfl-1 to preferentially suppress chemotherapy-induced apoptosis

Recent evidence indicates that the transcription factor NF-kappaB is a major effector of inducible antiapoptotic mechanisms. For example, it was shown that NF-kappaB activation suppresses the activation of caspase 8, the apical caspase in tumor necrosis factor (TNF) receptor family signaling cascades, through the transcriptional regulation of certain TRAF and IAP proteins. However, it was unknown whether NF-kappaB controls other key regulatory mechanisms in apoptosis. Here we show that NF-kappaB activation suppresses mitochondrial release of cytochrome c through the activation of the Bcl-2 family member A1/Bfl-1. The restoration of A1 in NF-kappaB null cells diminished TNF-induced apoptosis by reducing the release of proapoptotic cytochrome c from mitochondria. In addition, A1 potently inhibited etoposide-induced apoptosis by inhibiting the release of cytochrome c and by blocking caspase 3 activation. Our findings demonstrate that A1 is an important antiapoptotic gene controlled by NF-kappaB and establish that the prosurvival function of NF-kappaB can be manifested at multiple levels.

Development of a community-based diabetes management program for Pacific Islanders

PURPOSE

This study examined the perception of diabetes among a sample of Pacific Islanders in Honolulu, Hawaii. All 23 participants were diagnosed with type 2 diabetes, ranged in age from 21 to 70 years, and had glycosylated hemoglobin levels of 5.8% to 13.9%.

METHODS

Four focus groups were held in English and audiotaped. Outreach workers served as translators and comoderators. The content of transcripts was analyzed with Ethnograph software by investigators. The priority issues were confirmed by the comoderators and participants.

RESULTS

Participants perceived diabetes as full of complications, emotions, symptoms, and behavior changes. Responses to hyperglycemia were fear, frustration, and uncertainty. Barriers to staying on the prescribed diet were habit, cultural ritual, ideal body image, and limited budget.

CONCLUSIONS

Participants suggested that helpful activities would include walking/support group, cooking class, community healthy food store, translated material, and family participation. A community-based diabetes program has been developing as a result of the focus group findings.

Estimation of the correlation between nutrient intake measures under restricted sampling

Food frequency questionnaires (FFQs) are commonly used to assess dietary intake in epidemiologic research. To evaluate the FFQ reliability, the commonly used approach is to estimate the correlation coefficient between the data given in FFQ and those in food records (for example, 4-day food records [4DFR]) for nutrients of interest. However, in a dietary intervention study, a criterion for eligibility may be to select participants who have baseline FFQ-measured dietary intake of percent energy from fat above a prespecified quantity. Other instruments, such as the 4DFR, may be subsequently administrated only to eligible participants. Under these circumstances, analysis without adjusting for the restricted population will usually lead to biased estimation of correlation coefficients and other parameters of interest. In this paper, we apply likelihood-based and multiple imputation (MI) methods to accommodate such incomplete data obtained as a result of the study design. A simulation study is conducted to examine finite sample performance of various estimators. We note that both the MI estimate and the maximum likelihood (ML) estimate based on a bivariate-normal model are not sensitive to departures from this normality assumption. This led us to investigate robustness properties of the ML estimator analytically. We present some data analyses from a dietary assessment study from the Women's Health Initiative to illustrate the methods.

Responsiveness of human prostate carcinoma bone tumors to interleukin-2 therapy in a mouse xenograft tumor model

We have tested an immunotherapy approach for the treatment of metastatic prostate carcinoma using a bone tumor model. Human PC-3 prostate carcinoma tumor cells were heterotransplanted into the femur cavity of athymic Balb/c nude mice. Tumor cells replaced marrow cells in the bone cavity, invaded adjacent bone and muscle tissues, and formed a palpable tumor at the hip joint. PC-3/IF cell lines, generated from bone tumors by serial in vivo passages, grew with faster kinetics in the femur and metastasized to inguinal lymph nodes. Established tumors were treated with systemic interleukin-2 (IL-2) injections. IL-2 significantly inhibited the formation of palpable tumors and prolonged mouse survival at nontoxic low doses. Histologically IL-2 caused vascular damage and infiltration of polymorphonuclear cells and lymphocytes in the tumor as well as necrotic areas with apoptotic cells. These findings suggest destruction of tumor cells by systemic IL-2 therapy and IL-2 responsiveness of prostate carcinoma bone tumors.

Reduction of retrosternal and pericardial adhesions with rapidly resorbable polymer films

BACKGROUND

The formation of postoperative cardiac adhesions makes a repeat sternotomy time consuming and dangerous. Many attempts have been made to solve this problem by using either drugs to inhibit fibrinolytic activity or different types of pericardial substitutes. The results have not been satisfactory.

METHODS

The efficacy of bioresorbable film prototypes made of polyethylene glycol (EO) and polylactic acid (LA) (EO/LA = 1.5, 2.5, and 3.0) in the prevention of adhesions after cardiac operations in canine models was tested. After desiccation and abrasion of the epicardium, a transparent bioresorbable film was placed over the heart. The pericardium was closed to allow intrapericardial adhesions (n = 32) or left open and attached to the chest wall to induce retrosternal adhesions (n = 17). Postoperative recovery was similar among the groups. Retrosternal and pericardial adhesions were evaluated at necropsy 3 weeks later by assessing area, tenacity, and density of the adhesions.

RESULTS

In the control dogs, tenacious, dense adhesions were observed. In contrast, adhesion formation was reduced at all sites covered by the films. The bioresorbable films were efficacious in the reduction of adhesion formation between epicardium and pericardium or between epicardium and sternum after cardiac operation. The EO/LA 1.5 film most effectively prevented the early adhesions.

CONCLUSIONS

The bioresorbable films (EO/LA = 1.5, 2.5, and 3.0) significantly reduced adhesion formation, with EO/LA = 1.5 (Repel CV) being optimal. As the barrier was rapidly resorbed, the capsule formation induced by permanent barriers was avoided.

Epithelial proliferation and expression of the aromatic amine activation enzyme N-acetyltransferase in the prostate of postnatal rat

Male ACI/seg rats of different postnatal ages were injected, i.p., with 150 mg/kg bromodeoxyuridine one hour before being sacrificed. The incorporation of this compound into the DNA of prostate epithelium was detected immunohistochemically. The labeling indices in prostate epithelium were 16.8, 26.5 and 13.7%, in 3, 11 and 17 days old rats, respectively. It decreased gradually thereafter to 1.8% in 60 days old rats. The mRNA of N-acetyltransferase 1 was detected by a non-isotopic in situ hybridization method using a mixture of specific digoxigenin-11-dUTP-labeled oligodeoxynucleotide probes. The mRNA of N-acetyltransferase 1 was detected during the entire postnatal period. It was not detected in the stromal or endothelial cells. The coincidence of N-acetyltransferase expression in actively proliferating prostate epithelial cells during the postnatal period suggest that the prostate tissue may be particularly sensitive during this period to the carcinogenesis by aromatic and heterocyclic amines.

Postexposure immunoprophylaxis of primary isolates by an antibody to HIV receptor complex

mAb B4 is a monoclonal antibody directed against HIV receptor complex. The antibody had broad neutralizing activity against HIV and provided postexposure prophylaxis to hu-peripheral blood leukocyte (PBL)-severe combined immunodeficient mice and chimpanzees. B4 recognized a complex receptor site for HIV on the T cell surface that includes CD4 and also may be influenced by interaction with HIV coreceptors. mAb B4 preferentially neutralized primary HIV-1 isolates compared with T cell line-adapted strains, including syncytium-inducing and non-syncytium-inducing phenotypes, representatives from HIV-1 subtypes A-G, as well as HIV-2, simian immunodeficiency virus, and chimeric simian/human immunodeficiency virus (SHIV). Neutralization was demonstrated in both pre- and postinfection models. The administration of mAb B4 after infectious challenge totally interrupted the infection of hu-PBL-severe combined immunodeficient mice by PBL-grown HIV-1 and the infection of chimpanzees by chimp-adapted HIV-1. This mode of protection suggested that the anti-HIV receptor antibody is efficacious for prophylaxis after exposure to HIV and for prevention of maternal transmission and may be an effective antiretroviral agent for treatment.

Construction of a physical and transcript map for a 1-Mb genomic region containing the urofacial (Ochoa) syndrome gene on 10q23-q24 and localization of the disease gene within two overlapping BAC clones (<360 kb)

Urofacial (Ochoa) syndrome is an autosomal recessive disease characterized by distorted facial expression and urinary abnormalities. Previously, we mapped the UFS gene to chromosome 10q23-q24 and narrowed the interval to one YAC clone of 1410 kb. Here, we have constructed a BAC/PAC contig of the 1-Mb region using STS content mapping with 42 BAC/PAC-end sequences, 9 previously reported and 16 newly identified microsatellite markers, and 14 EST markers. A total of 26 polymorphic microsatellite markers were genotyped for 31 UFS patients from Colombia and 2 patients from the United States. Haplotype analyses suggest that the UFS gene is located within two overlapping BAC clones, a region of <360 kb of DNA sequence. We tested 42 EST markers previously mapped to the D10S1709-D10S603 interval against the BAC/PAC contig and identified 11 ESTs located in the 1-Mb region. Four of the 11 ESTs mapped to the 360-kb UFS critical region. Shotgun sequencing of the two BAC clones and BLASTN search of the EST databases revealed 3 other ESTs contained in the UFS critical region. These results will facilitate the cloning and identification of the UFS gene.

Differentiation of convalescent animals from those vaccinated against foot-and-mouth disease by a peptide ELISA

We have identified continuous antigenic determinants within the amino acid sequences of the conserved nonstructural region containing proteins 2C and 3ABC of foot-and-mouth disease virus which can distinguish between the sera from vaccinated and infected animals. An ELISA based on a 3B peptide gave a positive reaction with sera from cattle, pigs, sheep and guinea pigs infected with all seven serotypes of the virus, but not with sera from vaccinated animals. In experiments with cattle and pigs to determine the duration of the antibody response, positive reactions were obtained as late as one year after infection. The advantages of using peptides from the nonstructural viral proteins instead of recombinant proteins for differentiating vaccinees from infected animals include their exquisite specificity, nonreactivity with antibodies against host cell-derived proteins (e.g. E. coli and insect cell proteins), and their ease of preparation.

Differential signaling of glial cell line-derived neurothrophic factor and brain-derived neurotrophic factor in cultured ventral mesencephalic neurons

In the ventral mesencephalon, two neurotrophic factors, brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor, have been shown previously to have similar effects on the survival of dopaminergic neurons. Here, we compared the signaling mechanisms for brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor, focusing on the mitogen-associated protein kinase and the transcription factor cyclic-AMP responsive element-binding protein. Double-staining experiments indicated that many neurons co-expressed the receptors for glial cell line-derived neurotrophic factor and brain-derived neurotrophic factor, c-RET and TrkB, suggesting that they are responsive to both brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor. Although both brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor induced a rapid phosphorylation of mitogen-associated protein kinase and cyclic-AMP, responsive element-binding protein, there were significant differences in the kinetics and pharmacology of the phosphorylation. The phosphorylation of mitogen-associated protein kinase by glial cell line-derived neurotrophic factor was transient; within 2 h, the level of mitogen-associated protein kinase phosphorylation returned to baseline. In contrast, the effect of brain-derived neurotrophic factor was long lasting; the mitogen-associated protein kinase remained phosphorylated for up to 4 h after brain-derived neurotrophic factor treatment. PD098059, a specific inhibitor for mitogen-associated protein kinase kinase, completely blocked the glial cell line-derived neurotrophic factor signaling through mitogen-associated protein kinase, but had no effect on brain-derived neurotrophic factor-induced mitogen-associated protein kinase phosphorylation. Both brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor induced the phosphorylation of cyclic-AMP responsive element-binding protein in the nuclei of ventral mesencephalon neurons. However, PD098059 blocked the cyclic-AMP responsive element-binding protein phosphorylation induced by glial cell line-derived neurotrophic factor, but not that by brain-derived neurotrophic factor. These results indicate that, although both brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor act on ventral mesencephalon neurons, the two factors have different signaling mechanisms, which may mediate their distinctive biological functions.

Dead-on-arrival patients in Panchiao, Taipei

BACKGROUND

The present emergency medical service (EMS) system in the Panchiao area includes operations in Panchiao, Sulin, Sunshia, Chung Ho and Touchen, which is in the early developmental stage. Educational programs such as emergency medical technician (EMT)-I, and -II have been provided for less than 25% of firefighters in that area. Several mass educational programs in cardiopulmonary resuscitation (CPR) were also provided for the inhabitants of the area. The purpose of this study was to establish a database of dead-on-arrival (DOA) patients during this early stage of the EMS system development so that comparisons of EMS performance could be assessed to identify any future needs of the EMS system in the Panchiao area.

METHODS

A patient was verified as DOA if there was no pulse nor a response to stimulation. For every DOA patient, several parameters were recorded in a registration book, which began January 1, 1995, and included the following: name, gender, age, mode of transportation, time to hospitalization, on-scene CPR, prehospital basic life support, possible etiology, response to advanced cardiac life support (ACLS), disposition and outcome. The registration book was reviewed and a follow-up study was designed, which covered the entire year of 1995.

RESULTS

There were 292 DOA patients brought to the emergency room of the Far Eastern Memorial Hospital in Panchiao, Taipei, between January 1, 1995, and December 31, 1995. The study population comprised 190 (65.1%) men and 102 (34.9%) women. The mean age of the men was 51.8 +/- 22.3 years (mean +/- standard deviation). The mean age of the women was 59.8 +/- 24.4 years. Emergency service ambulances transported most DOA patients, though a few were transported by private ambulance from nursing homes. There were only two incidents in which prehospital CPR was conducted. The time to hospitalization varied from five to 170 minutes and averaged 38.3 minutes. Following ACLS, 244 (83.6%) patients were pronounced dead in the emergency room. Cardiovascular and respiratory problems were the leading etiologies and trauma was the second. There were 48 patients (16.4%) who responded to ACLS, but only eight (2.7%) survived until hospital discharge.

CONCLUSIONS

Delayed initiation of the EMS system resulted in an average time to hospitalization of 38.3 minutes. Cardiovascular collapse was the leading etiology in DOA patients. There were only two patients who received prehospital CPR, suggesting that layperson CPR and EMT education cannot be overemphasized.

N-Acetyltransferase expression and DNA binding of N-hydroxyheterocyclic amines in human prostate epithelium

Intact prostate epithelial cells prepared from benign prostatic hypertrophy tissues from two patients were incubated for 2 h with N-hydroxy derivatives of 2-amino-1-methyl-6-phenylimidazo[4, 5-b]pyridine (N-OH-PhIP) or 2-amino-3,8-dimethylimidazo[4, 5-f]quinoxaline (N-OH-MeIQx). (32)P-post-labeling analysis detected PhIP and MeIQx adducts in the DNA of these cells but not in the untreated control. Adduct levels were approximately 100 times greater in N-OH-PhIP- than in N-OH-MeIQx-treated cells. Repair synthesis of DNA was observed in cells, prepared from two additional patients, treated for 24 h with these carcinogens and was greater for N-OH-PhIP than for N-OH-MeIQx. PhIP, MeIQx and their nitro derivatives did not produce repair synthesis of DNA in this system. The difference in the activity of N-OH-PhIP and N-OH-MeIQx may be due to their stability, since N-OH-MeIQx decomposed rapidly in neutral solution. Transcripts of NAT1 and NAT2 were detected by an in situ hybridization method in prostate epithelial cells, but were absent from stromal tissues. These results suggest that PhIP may be a potential carcinogen for human prostate, since cooked meats, which contain this heterocyclic amine, have been associated with human prostate cancer.

[Role of red nucleus in inhibiting nociceptive responses of rat spindle afferent]

Using extracellular recording techniques, the effect of excitation of red nucleus (RN) on C-responses of wide dynamic range (WDR) neurons and the roles of RN in the inhibitory effect of spindle afferent activated by succinycholine (SCH) on C-responses of WDR neurons were studied. Stimulation of RN caused a significant reduction of nociceptive responses of WDR neurons, which was significantly attenuated by intravenous cyproheptadine and contralateral lesion of RN. These results suggest that the inhibitory effect on nociceptive responses of WDR neurons caused by RN stimulation was partly mediated by 5-HT and RN plays an important role in analgesia induced by the muscle spindle afferent activity.

WT1 modulates apoptosis by transcriptionally upregulating the bcl-2 proto-oncogene

The Wilms' tumor suppressor gene, WT1, encodes a zinc finger transcription factor that has been demonstrated to negatively regulate several growth factor and cognate receptor genes. However, inconsistent with its tumor suppressor function, WT1 has also been demonstrated to be required to inhibit programmed cell death in vitro and in vivo. Moreover, anaplastic Wilms' tumors, which typically express wild-type WT1, display extreme resistance to chemotherapeutic agents that kill tumor cells through the induction of apoptosis. Although p53 mutations in anaplastic Wilms' tumors have been associated with chemoresistance, this event is believed to occur late during tumor progression. Therefore, since dysregulated WT1 expression occurs relatively early in Wilms' tumors, we hypothesized that WT1 was required to transcriptionally upregulate genes that provide a cell survival advantage to tumor cells. Here we demonstrate that sporadic Wilms' tumors coexpress WT1 and the anti-apoptotic Bcl-2 protein. Using rhabdoid cell lines overexpressing WT1, we show that WT1 activates the endogenous bcl-2 gene through a transcriptional mechanism. Transient transfections and electromobility shift assays demonstrate that WT1 positively stimulates the bcl-2 promoter through a direct interaction. Moreover, WT1 expressing cells displaying upregulated Bcl-2 were found to be resistant to apoptosis induced by staurosporine, vincristine and doxorubicine. These data suggest that in certain cellular contexts, WT1 exhibits oncogenic potential through the transcriptional upregulation of anti-apoptotic genes such as bcl-2.