Nondestructive in situ thermoluminescence using CO(2) laser heating

We have obtained thermoluminescence glow curves nondestructively from large, solid, ceramic samples by laser spot heating. Although the samples are brittle, laser thermoluminescence glow curves could be obtained with no visible damage to the samples. The experimental glow curves match with theory. By contrast, conventional thermoluminescence measurements require small samples to be removed from a ceramic and placed in a thermoluminescence machine. Laser-induced thermoluminescence glow curves from LiF, silica, and porcelain are presented.

Life threatening acute epiglottitis in acute leukemia

We report an 8-year-old boy who developed a life-threatening acute epiglottitis during induction chemotherapy for acute promyelocytic leukemia. He survived the infection with emergency tracheostomy, treatment with broad spectrum antibiotics and amphotericin, and the use of granulocyte-macrophage colony stimulating factor. No organism was identified. A literature review identified 18 cases of acute epiglottitis in cancer patients. Sixteen of them were suffering from hematologic malignancies and three patients had received bone marrow transplantation. Unlike the usual case of epiglottitis, the majority (15 out of 18) of affected patients were adults and none of the infections was associated with Haemophilus influenzae. Streptococcus pneumoniae and Candida albicans were the most frequently identified pathogens. Early recognition and aggressive supportive care are required for successful management.

Non-coplanar inverse planning IMRT using the MIMiC system: clinical significance in choice of 2-cm/1-cm mode and single couch vs. multiple couch angles

The IMRT delivery process using MIMiC is extremely effective. In the hands of an experienced practitioner, MIMiC can provide excellent conformity to tumor volume with minimal damage to adjacent critical structures. However, the process is not completely automatic, even though it is an inverse planning process. The choice of machine treatment mode, 1- or 2-cm mode, and the choice of single couch angle vs. multiple, will yield quite different end results, with all prescription parameters being equal. The choice of mode and number of couch angles that yield excellent results of good coverage of the PTV with minimal hot spots and appropriate degree of normal tissue sparing still depends on the clinical experience of the planner. The size, shape, and total length of the PTV and those of the organs of interest dictate the choice. The authors demonstrated some clinical examples with comparative studies of the results of different choice of these parameters. In general, smaller beamlets with multiple couch angles give better PTV conformity, and critical organ avoidance. The down side of these choices are: (a) relatively more scattered hot spots within PTV, (b) longer time required to deliver the treatment, and (c) increased complexity of the process that could increase the chance of human error in treatment delivery.

A globin-coupled oxygen sensor from the facultatively alkaliphilic Bacillus halodurans C-125

We have recently discovered heme-containing signal transducers from the archaeon Halobacterium salinarum (HemAT-Hs) and the gram-positive bacterium Bacillus subtilis (HemAT-Bs). These proteins bind diatomic oxygen and trigger aerotactic responses. We identified that HemAT oxygen-sensing domains contain a globin-coupled sensor (GCS) motif, which exists as a two-domain transducer, having no similarity to the PAS domain (Period circadian protein, Ah receptor nuclear translocator protein, Single-minded protein) superfamily transducers. Using the GCS motif, we predicted that a 439-amino-acid protein annotated as a methyl-accepting chemotaxis protein (MCP) in the facultatively alkaliphilic bacterium Bacillus halodurans is a globin-coupled oxygen sensor. We cloned, expressed, and purified GCS(Bh), and performed its spectral analysis. GCS(Bh), binds heme and shows myoglobin-like spectra. This suggests that GCS(Bh) acts as an oxygen sensor and transmits a conformational signal through a linked signaling domain to trigger an aerotactic response in B. halodurans.

Review of recent advances in fluorescence bronchoscopy in early localization of central airway lung cancer

Centrally located lung cancers are radiologically occult until so far advanced as to have a low cure rate or require extensive resection for cure, but at a cost of high morbidity. These cancers represent about one-fifth of new lung cancers. Autofluorescence bronchoscopy appears to be an important tool in localizing premalignant and early malignant lesions in the large central airways, particularly when applied to high-risk patients. Applications include studies of molecular biology of premalignancy and early malignancy, chemoprevention studies, endobronchial therapy studies, localization of synchronous tumors, estimation of the extent of field cancerization, and better estimation of resection margins. Autofluorescence bronchoscopy appears to be significantly more sensitive than white light examination but has low specificity. This technology is likely to gain widespread use when evaluation of sputum for malignant changes is both more sensitive and specific, and when its application is demonstrated to reduce mortality in this important subgroup of non-small cell lung cancer patients.

A unitary patient record improves admission documentation in a medical assessment unit in a major teaching hospital

OBJECTIVE

To ascertain the impact of the introduction of a unitary patient record (UPR) on clerking documentation of emergency medical admissions.

DESIGN

Retrospective casenote audit.

SUBJECTS AND SETTING

Random sample of 100 unselected admissions to the medical assessment unit of a major teaching hospital, comprising two groups pre- and post-introduction of the UPR.

RESULTS

Statistically significant improvements in the documentation of several items were achieved; function before episode, ethnic origin, chest pain, breathlessness, ankle oedema, cough, bowel habit and locomotor symptoms and recording of blood pressure and peripheral pulses. There were trends towards improvement in other areas and there were no areas in which the UPR performed less well than standard documentation.

CONCLUSIONS

Introduction of the UPR represents the successful application of multidisciplinary principles to over 10,000 acute general medical admissions. It has improved some, but not all, aspects of documentation. Revision of the design of the UPR should lead to further progress, as part of an ongoing process of development and re-audit.

Local regulation of anion secretion by pituitary adenylate cyclase-activating polypeptide in human colonic T84 cells

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a novel hypothalamic peptide, which has been shown to exert various functions in a number of tissues, including exocrine and endocrine tissues. The present study investigated the role of local PACAP in the control of anion secretion by the human colonic T84 cell. Both bioactive forms of PACAP-27 and PACAP-38 gave rise to a dose-dependent increase in the short-circuit current (I(SC)). However, there was a reversal in the order of potency observed at different concentration ranges for the two bioactive forms. PACAP-27 was greater than PACAP-38 when the peptide concentrations were below 10 n m; PACAP-38 was greater than PACAP-27 in the range of 10-80 n m. The effects of both PACAP forms were restricted to the apical aspect of the T84 cell. The I(SC)responses to both PACAP-27 and PACAP-38 were suppressed respectively by the non-selective Cl(-)channel blocker, diphenylamine-dicarboxylic acid (DPC), by the Ca(2+)dependent Cl(-)channel blocker, diisothiocyanatostilbene-disulfonic acid (DIDS) and by the Ca(2+)chelator, BAPTA-AM, indicating the involvement of Ca(2+). The expression of PACAP was demonstrated and localized specifically to the perinuclear cytoplasm of the T84 cell using immunocytochemistry, indicating its epithelial origin. Thus, the present data suggest that, in addition to the well-known cAMP-dependent pathway, PACAP may play a role in regulating colonic Cl(-)secretion via a Ca(2+)-dependent pathway, perhaps through two distinct PACAP receptor subtypes. Moreover, the regulation of anion secretion by T84 cells may be mediated by locally formed PACAP in an autocrine or paracrine fashion.

Isolation, culture, characterization and use of human renal tubular epithelial cells

Tubulointerstitial alterations are a hallmark of most renal diseases. In vitro culture of different cell types of the tubulointerstitial compartment have been instrumental in studying their respective contributions to the inflammatory and fibrotic process. The present paper provides an overview of the isolation, culture and characterization of tubular epithelial cells, with a main emphasis on cells from human origin.

5' CpG island methylation of the FHIT gene is correlated with loss of gene expression in lung and breast cancer

Allele loss and loss of expression of fragile histidine triad (FHIT), a putative tumor suppressor gene located in chromosome region 3p14.2, are frequent in several types of cancers. Tumor-acquired methylation of promoter region CpG islands is one method for silencing tumor suppressor genes. We investigated 5' CpG island methylation of the FHIT gene in 107 primary non-small cell lung cancer (NSCLC) samples and corresponding nonmalignant lung tissues, 39 primary breast carcinomas, as well as in 49 lung and 22 breast cancer cell lines by a methylation-specific PCR assay. In addition, we analyzed brushes from the bronchial epithelium of 35 heavy smokers without cancer. FHIT methylation was detected in 37% of primary NSCLCs, 31% of primary breast cancers, and 65% of lung and 86% of breast cancer cell lines. The frequency of methylation in small cell and NSCLC cell lines were identical. Methylation was found in 9% of the corresponding nonmalignant lung tissues and in 17% of bronchial brushes from heavy cigarette smokers. FHIT methylation was significantly correlated with loss of FHIT mRNA expression by Northern blot analysis in lung cancer cell lines and with loss of Fhit expression in NSCLC and breast tumors by immunostaining. We conclude that methylation of FHIT is a frequent event in NSCLC and breast cancers and is an important mechanism for loss of expression of this gene. Methylation of FHIT commences during lung cancer pathogenesis and may represent a marker for risk assessment.

Early detection for lung cancer. New tools for casefinding

OBJECTIVE

To review data from published population trials and clinical practice guidelines on screening for lung cancer to provide a recommendation for early detection of lung cancer.

QUALITY OF EVIDENCE

Literature was searched via MEDLINE using the MeSH headings "lung neoplasm," "mass screening," "thoracic radiography," and "sputum." Only prospective randomized controlled trials with large numbers of subjects were selected.

MAIN MESSAGE

Risk of lung cancer among long-term heavy smokers continues even years after stopping smoking. Risk is highest in smokers with chronic obstructive pulmonary disease. Canadian clinical practice guidelines currently recommend that sputum cytology examination and chest radiography (CXR) not be used for lung cancer screening. This guideline was deducted from four randomized population trials in the 1970s that have serious limitations and applies to asymptomatic adults only. A CXR and sputum cytology examination are indicated in symptomatic current and former smokers older than 45 years with a smoking history of 30 pack-years or more and airflow obstruction defined as a forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) of 70% or less and a FEV1 lower than 70%. Curative treatment is available for early lung cancer. Substantial advances in innovative technologies for early detection using low-dose spiral CT and newer sputum tests have been made in the last three decades. Additional studies are under way to evaluate these new technologies.

CONCLUSION

Primary care physicians have an important role in identifying people at risk of developing lung cancer and in supporting research to evaluate new screening technology.

Protective role of cyclooxygenase inhibitors in the adverse action of passive cigarette smoking on the initiation of experimental colitis in rats

Clinical and experimental findings had indicated that cigarette smoke exposure, and cyclooxygenase-2, are strongly associated with inflammatory bowel disease. The present study aimed to evaluate the role of cyclooxygenase-2 in the pathogenesis of experimental inflammatory bowel disease as well as in the adverse action of cigarette-smoke exposure. Rats were pretreated with different cyclooxygenase-2 inhibitors (indomethacin, nimesulide, or SC-236 (4-[5-(4-chlorophenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]benzenesulfonamide)) along with cigarette-smoke exposure before 2,4,6-trinitrobenzenesulfonic acid-enema. Results indicated that pretreatment with cyclooxygenase-2 inhibitors not only protected against 2,4,6-trinitrobenzenesulfonic acid-induced inflammatory bowel disease, but also attenuated the potentiating effect of cigarette-smoke exposure on colonic damage. Furthermore, the colonic cyclooxygenase-2 protein and mRNA expression was markedly induced by 2,4,6-trinitrobenzenesulfonic acid-enema, and it was potentiated further by cigarette-smoke exposure, while the cyclooxygenase-1 expression was not changed. The present study suggests that the highly induced cyclooxygenase-2 expression not only plays a pathogenic role in 2,4,6-trinitrobenzenesulfonic acid-induced inflammatory bowel disease, but also contributes to the adverse action of cigarette-smoke exposure on this disorder.

Cultural expectations of thinness in Chinese women

The present study examined the ideal woman's figure among Chinese people in Hong Kong over the past three decades by analyzing the data from the Miss Hong Kong Beauty Pageant from 1975-2000. Results indicate that Miss Hong Kong Pageant winners and Miss Photogenic winners have always been taller and thinner than average women in Hong Kong. The data also suggest that a curvaceous body shape with a narrow waist set against full hips appears to be an important component of feminine beauty among the Chinese. This ideal matches closely to what has been depicted in classical Chinese literature and challenges the commonly held belief that Chinese feminine beauty standards value plumpness.

Functional expression of angiotensin II receptors in type-I cells of the rat carotid body

Angiotensin II increases afferent discharge from the carotid body in vitro. We hypothesized that angiotensin II receptors (AT receptors) are expressed functionally in the type-I cell of the carotid body. Cytosolic free [Ca2+] ([Ca2+]i) in type-I cells freshly dissociated from rat carotid bodies was measured spectrofluorimetrically. Angiotensin II (10-100 nM) concentration-dependently increased [Ca2+]i in type-I cells. The [Ca2+]i response was blocked by pretreatment with losartan (1 microM), an AT1 receptor antagonist, but not by blockade of AT2 receptors with PD- 123319 (1 microM). Moreover, the gene expression of AT1 receptors was assessed by the reverse transcriptase polymerase chain reaction and gene transcripts of both AT1a and AT1b receptors were detected in the carotid body. In addition, immunohistochemical study revealed that AT1 immunoreactivity was localized in lobules of type-I cells in the carotid body. Taken together, these results suggest that type-I cells in the rat carotid body express functional angiotensin II receptors. The binding of angiotensin II to the AT1 receptors increases [Ca2+]i, a key step of the intracellular signalling cascade following the activation of the receptors. It is concluded that angiotensin II modulates carotid body chemoreceptor function directly via AT1 receptors in the type-I cell.

Detection and localization of early lung cancer by fluorescence bronchoscopy

BACKGROUND

Curative therapy is available for patients with Stage 0 lung carcinoma, with a >90% 5-year survival rate. Promising chemopreventive agents also are under investigation currently to reduce the risk of lung carcinoma in high risk populations. However, preinvasive bronchial lesions (moderate to severe dysplasia and carcinoma in situ) are very small and thin. They are difficult to localize by conventional white-light bronchoscopy. Fluorescence bronchoscopy is a new diagnostic tool for the detection of these preinvasive lesions.

METHODS

The data on the use of fluorescence bronchoscopy to detect and localize preinvasive lesions in current heavy smokers and in former smokers at the British Columbia Cancer Agency as well as the worldwide experience cited in MEDLINE, Index Medicus, and Deutsches Institut fur Medizinische Dokumentation und Information (Cologne, Germany) comparing white-light and fluorescence bronchoscopy using the lung imaging fluorescence endoscope (LIFE)-Lung device (Xillix Technologies Corp., Richmond, British Columbia, Canada) were reviewed.

RESULTS

Among current heavy smokers and former smokers with sputum atypia, the prevalence of carcinoma in situ was 1.6%. Moderate or severe dysplasia was found in another 19%. The preinvasive lesions were found to be small: 55% measured < or = 1.5 mm in greatest dimension. Over 1000 cases have been reported in the literature between 1994 and 1999. Overall, 40% of the preinvasive lesions were detected by white-light bronchoscopy alone. The addition of fluorescence bronchoscopy increased the detection rate to an average of 80%.

CONCLUSIONS

Preinvasive lesions, especially dysplastic lesions, are small. They are difficult to detect and localize by white-light bronchoscopy. Fluorescence bronchoscopy improves the detection rate. It is an important part of the armamentarium in the overall management of early lung cancer.

Chronic hypoxia upregulates the expression and function of AT(1) receptor in rat carotid body

In the present study, the effects of chronic hypoxia on the expression and localization of angiotensin II (Ang II) receptors are investigated by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and by immunohistochemistry. The effect of chronic hypoxia on the carotid body chemoreceptor activity was also examined by in vitro electrophysiology. Results from RT-PCR revealed that chronic hypoxia exhibited differential effects on the gene expression of Ang II receptors, namely AT(1) and AT(2), in the carotid body. The mRNA expression for subtypes of the AT(1) receptor, AT(1a) and AT(1b), was significantly increased in the carotid body with chronic hypoxia. To further investigate the localization of the AT(1) receptor, an immunohistochemical study was performed. The results showed that AT(1) receptor immunoreactivity was found in lobules of glomus cells in the carotid body and the immunoreactivity was more intense in chronic hypoxia than in normoxic controls. In vitro electrophysiological studies consistently demonstrated that chronic hypoxia enhanced the AT(1) receptor-mediated excitation of carotid body chemoreceptor activity. These data suggest that chronic hypoxia upregulates the transcriptional and post-transcriptional expression of AT(1) receptors in the rat carotid body. The upregulation of the expression also enhances AT(1) receptor-mediated excitation of the carotid body afferent activity. This might be important in the modulation of cardiorespiratory functions as well as fluid and electrolyte homeostasis during chronic hypoxia.

Intranuclear huntingtin increases the expression of caspase-1 and induces apoptosis

Expansion of a polyglutamine repeat in huntingtin causes Huntington's disease (HD). Although full-length huntingtin is predominantly distributed in the cytoplasm, N-terminal fragments of huntingtin with expanded polyglutamine tracts are able to accumulate in the nucleus and kill neurons through apoptotic pathways. Transgenic mice expressing N-terminal mutant huntingtin show intranuclear huntingtin accumulation and develop progressive neurological symptoms. Inhibiting caspase-1 can prolong the survival of these HD mice. How intranuclear huntingtin is associated with caspase activation and apoptosis is unclear. Here we report that intranuclear huntingtin induces the activation of caspase-3 and the release of cytochrome c from mitochondria in cultured cells. As a result, cells expressing intranuclear huntingtin undergo apoptosis. We show that intranuclear huntingtin increases the expression of caspase-1, which may in turn activate caspase-3 and trigger apoptosis. We propose that the increased level of caspase-1 induced by intranuclear huntingtin contributes to HD-associated cell death.

Combination therapy with lamivudine and famciclovir for chronic hepatitis B-infected Chinese patients: a viral dynamics study

In vitro studies have shown that lamivudine and penciclovir (the active metabolite of famciclovir) act synergistically to inhibit hepatitis B virus (HBV) replication. We compared the effectiveness of HBV viral suppression by lamivudine monotherapy versus lamivudine plus famciclovir combination therapy in Chinese patients with chronic HBV infection. Twenty-one Chinese hepatitis B e antigen (HBeAg)-positive patients, with detectable HBV DNA (Digene Hybrid Capture II), were randomized to receive either lamivudine 150 mg/d orally (group 1, 9 patients) or lamivudine 150 mg/d plus famciclovir 500 mg 3 times a day orally (group 2, 12 patients) for 12 weeks, with a follow-up period of at least 16 weeks. Serial serum HBV-DNA levels were determined and a mathematical model with provision for incomplete inhibition of virus production during therapy was applied to analyze the dynamics of viral clearance. The mean antiviral efficacy was significantly greater in group 2 than in group 1 (0.988 +/- 0.012 vs. 0.94 +/- 0.03, P =.0012). HBV DNA returned to pretreatment level within 16 weeks after the end of initial treatment in 4 patients (66.7%) in group 1 and none in group 2 (P =.08), who remained HBeAg positive and received no further treatment after week 12. Hence, in Chinese chronic HBeAg-positive patients, combination therapy using lamivudine and famciclovir was superior to lamivudine monotherapy in inhibiting HBV replication. Further studies of longer duration are needed to define whether combination therapy will increase the HBeAg seroconversion rate and decrease the rate of emergence of lamivudine-resistant variants.

The BMP1 gene is essential for pathogenicity in the gray mold fungus Botrytis cinerea

In Magnaporthe grisea, a well-conserved mitogen-activated protein (MAP) kinase gene, PMK1, is essential for fungal pathogenesis. In this study, we tested whether the same MAP kinase is essential for plant infection in the gray mold fungus Botrytis cinerea, a necrotrophic pathogen that employs infection mechanisms different from those of M. grisea. We used a polymerase chain reaction-based approach to isolate MAP kinase homologues from B. cinerea. The Botrytis MAP kinase required for pathogenesis (BMP) MAP kinase gene is highly homologous to the M. grisea PMK1. BMP1 is a single-copy gene. bmp1 gene replacement mutants produced normal conidia and mycelia but were reduced in growth rate on nutrient-rich medium. bmp1 mutants were nonpathogenic on carnation flowers and tomato leaves. Re-introduction of the wild-type BMP1 allele into the bmp1 mutant restored both normal growth rate and pathogenicity. Further studies indicated that conidia from bmp1 mutants germinated on plant surfaces but failed to penetrate and macerate plant tissues. bmp1 mutants also appeared to be defective in infecting through wounds. These results indicated that BMP1 is essential for plant infection in B. cinerea, and this MAP kinase pathway may be widely conserved in pathogenic fungi for regulating infection processes.

Perceptual style and behavioral pattern of individuals with functional gastrointestinal disorders

The present research examined the perceptual style and coping pattern characterizing individuals with functional gastrointestinal disorders. A matched case-control design was adopted to compare differences among the target group of individuals with functional gastrointestinal disorders (n = 40), a pain control group of individuals with rheumatism (n = 40), and the community control group of healthy individuals (n = 40). Perceptual style was measured by both monitoring and blunting responses to hypothetical stressful situations, and coping pattern was measured by the use of coping strategies in real-life stressful events. Results revealed that participants with functional gastrointestinal disorders differed from their healthy and rheumatic counterparts in having higher monitoring and lower blunting scores and using action-oriented coping strategies regardless of the controllability of stressful situations.