A multi-scale view of skin thermal pain: from nociception to pain sensation

All biological bodies live in a thermal environment, including the human body, where skin is the interface with a protecting function. When the temperature is out of the normal physiological range, skin fails to protect, and the pain sensation is evoked. Furthermore, in medicine, with advances in laser, microwave and similar technologies, various thermal therapeutic methods have been widely used to cure disease/injury involving skin tissue. However, the corresponding problem of pain relief has limited further application and development of these thermal treatments. Skin thermal pain is induced through both direct (i.e. an increase/decrease in temperature) and indirect (e.g. thermomechanical and thermochemical) ways, and is governed by complicated thermomechanical-chemical-neurophysiological responses. However, a complete understanding of the underlying mechanisms is still far from clear. In this article, starting from an engineering perspective, we aim to recast the biological behaviour of skin in engineering system parlance. Then, by coupling the concepts of engineering with established methods in neuroscience, we attempt to establish multi-scale modelling of skin thermal pain through ion channel to pain sensation. The model takes into account skin morphological plausibility, the thermomechanical response of skin tissue and the biophysical and neurological mechanisms of pain sensation.

Functional variations in the JWA gene are associated with increased odds of leukemias

The association between the -76G>C in the 5'-flanking region and 723T>G in JWA exon three variants were examined for risk of leukemia development in a hospital-based case-control study of 201 leukemia patients and 243 cancer-free controls in a Chinese population. Studies showed that the -76C allele was associated with significantly increased odds of leukemia but the 723G allele was correlated with marked decreased odds of leukemia. Variation in the -76C allele resulted in almost complete loss of oxidative stress stimulated transcription activities of the promoter fragment.

Identification and functional characterization of JWA polymorphisms and their association with risk of gastric cancer and esophageal squamous cell carcinoma in a Chinese population

Recently, a novel single nucleotide polymorphism (SNP) in the promoter of the JWA gene (-76G --> C) was identified that may alter the transcription activity and thus play a role in increased risk of bladder cancer. In this study, a screen for more novel variants in the JWA exons was undertaken by using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) followed by a PCR-restriction fragment length polymorphism (PCR-RFLP) method and evaluating the functions of newl identified JWA -76G --> C using the reporter gene assay. In addition to the -76G --> C polymorphism, another novel SNP (723T --> G) in exon 3 of JWA was identified. In a case-control study of these two SNPs in 413 gastric cancer and 250 esophageal squamous-cell carcinoma (ESCC) patients and 814 cancer-free controls in a Chinese population, data showed that both SNPs were associated with enhanced risk of these cancers. The reporter gene assay showed that the -76C variant allele lost its response to benzo[a]pyrene (BaP) exposure, compared to the -76G allele. In addition, the JWA -76C allele was found to be associated with increased gastric and esophageal cancer risks in this study population. Further studies are needed to substantiate the biological significance and related mechanisms underlying the associations.

Functional polymorphisms of JWA gene are associated with risk of bladder cancer

The JWA gene is a novel cell differentiation-related gene thought to be a responsive gene in response to DNA damage and repair induced by environmental stressors. Recently, a novel single nucleotide polymorphism (SNP) was identified in the promoter of the JWA gene (-76GC) that may alter the transcription activity and thus play a role in increased risk of bladder cancer. Further, studies were conducted to screen for more novel variants in the JWA exons by using PCR-SSCP (polymerase chain reaction-single-strand conformation polymorphism) followed by PCR-RFLP (PCR restriction fragment length polymorphism) methods. Finally, the functional relevance of the newly identified genetic variants in a hospital-based case-control study of 215 bladder cancer patients and 250 cancer-free controls was evaluated. In addition to the -76GC polymorphism, another novel SNP (454CA in exon2 and 723TG in exon 3) of JWA was identified. The -76GC allele and genotype frequencies were found to vary in different ethnic groups. The -76C allele and 454A allele were both associated with significantly increased risk of bladder cancer. In contrast, the 723GG genotype was associated with a decreased risk of bladder cancer. Furthermore, -76C and 454A together increased the risk of bladder caner using haplotype and stratification analysis. In conclusion, the three novel functional genetic polymorphisms of JWA gene, -76GC, 454CA, and 723TG, appear to contribute to the etiology of bladder cancer.

Single nucleotide polymorphism of the JWA gene is associated with risk of leukemia: a case-control study in a Chinese population

The JWA gene was initially cloned as a novel cell differentiation-associated gene and was subsequently found to be an environmental responsive gene. The JWA gene also produced a marked effect during chemical-induced multidirectional differentiations of primary and human myeloid leukemia cells. Recently, a novel single nucleotide polymorphism (SNP) in exon2 of the JWA gene (454CA) was identified that may play a role in risk of bladder cancer. The aim of this study was to investigate the association between the 454CA (NM_006407.2) in JWA exon2 variants and risk of leukemia in a hospital-based case-control study of 202 leukemia patients and 289 cancer-free controls. Results indicated that 454A allele was found to associate with significantly increased risk of leukemia, although the 454CA is a synonymous polymorphism in coding region of the JWA gene. In conclusion, the potentially functional genetic polymorphism 454CA of the JWA gene appears to contribute to the risk of multiple kinds of leukemia in a south Chinese population.

Green fluorescent protein as a visual selection marker for papaya (Carica papaya L.) transformation

Chemical-based selection for plant transformation is associated with a number of real and perceived problems that might be avoided through visual selection. We have used green fluorescent protein (GFP), as a visual selectable marker to produce transformed papaya ( Carica papaya) plants following microprojectile bombardment of embryogenic callus. GFP selection reduced the selection time from 3 months on a geneticin (G418) antibiotic-containing medium to 3-4 weeks. Moreover, GFP selection increased the number of transformed papaya plants by five-to eightfold compared to selection in the presence of antibiotics. Overall, the use of GFP for selecting transgenic papaya lines improved our throughput for transformation by 15- to 24-fold while avoiding the drawbacks associated with the use of antibiotic resistance-based selection markers.

Effects of decreasing the frequency of ventilator circuit changes to every 7 days on the rate of ventilator-associated pneumonia in a Beijing hospital

INTRODUCTION

We investigated whether decreasing ventilator circuit changes from every 2 days to every 7 days would impact ventilator-associated pneumonia rates at our institution.

METHODS

All mechanically ventilated patients at Peking Union Medical College Hospital were studied over a 21 month period. From March 1998 to February 1999, ventilator circuits were changed every 2 days, and from June through December 1999, ventilator circuits were changed every 7 days. Nosocomial pneumonia was identified using the criteria of the Centers for Disease Control.

RESULTS

In the 2-day-change group, there were 2,277 ventilator-patient days and 38 patients developed pneumonia, resulting in a pneumonia rate of 16.7 cases per 1,000 ventilator days. The 7-day-change group accumulated 972 ventilator days and 8 patients contracted pneumonia, resulting in a pneumonia rate of 8.2 cases per 1,000 ventilator days. The pneumonia rate was significantly lower in the 7-day-change group (p = 0.007). To standardize for seasonal variability, we compared results from the same seasonal time frames (June to December 1998 for the 2-day-change group, and June to December 1999 for the 7-day-change group), and obtained similar findings: during those periods, pneumonia rates were 24.2 cases per 1,000 ventilator days for the 2-day-change group and 8.9 cases per 1,000 ventilator days for the 7-day-change group (p = 0.001).

CONCLUSIONS

A circuit change interval of 7 days had a lower risk of ventilator-associated pneumonia than a 2-day change interval. Therefore, ventilator circuits can be safely changed every 7 days in our setting.

Surface chemical characterization of 2.5-microm particulates (PM2.5) from air pollution in Salt Lake City using TOF-SIMS, XPS, and FTIR

Particulate matter with a diameter of 2.5 microm collected in Salt Lake City (SLC PM2.5) was studied using TOF-SIMS (time-of-flight secondary-ion mass spectrometry), XPS (X-ray photoelectron spectroscopy), and FTIR (Fourier transform infrared spectroscopy). The high spatial resolution and high surface sensitivity of TOF-SIMS allow the surfaces of individual particulates to be analyzed. The high mass-resolution of TOF-SIMS provides good separation of signals from different chemical species at the same nominal mass, and the extremely high detection sensitivity of TOF-SIMS makes the detection of trace elements possible. Metallic elements such as Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Cu, Zn, Cs, and Bi were detected by TOF-SIMS on the surface of SLC PM25. The uranium ion U+ together with its oxide ions UO+ and UO2+ were also found. Inorganic compounds detected include oxides, hydroxides, nitrates, sulfates, silicates, borates, chlorides, etc. Organic compounds detected include hydrocarbons, alcohols, aldehydes, ethers, carboxylic acids, amines, amides, nitriles, etc. A number of polycyclic aromatic hydrocarbons (PAH) and nitrated polycyclic aromatic hydrocarbons were detected by TOF-SIMS. High-resolution XPS Cls spectrum shows functional groups such as C-O, CO2, C-CO2, C-C, and C-H and aromatic pi-pi* shake-up transitions. High-resolution XPS O 1s spectrum indicates the coexistence of different oxygen compounds on the surface of PM2.5. FTIR results confirm the presence of various organic compounds in SLC PM2.5 detected by TOF-SIMS and XPS.

[Analysis of new type composite antioxidant by HPLC/APCI-MS]

An effective method for the analysis of a new type composite antioxidant has been developed. High performance liquid chromatography (HPLC) with diode-array detection (DAD) interfaced to atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) was used. In this paper, the major components of the composite antioxidant additive were identified by means of HPLC/APCI-MS with positive/negative ion scan modes and programmable in-source collision induced dissociation and infrared(IR) spectra. The results show that this method is rapid, convenient and very useful for the analysis of lubricant additives.

Fresh and nonfibrillar amyloid beta protein(1-40) induces rapid cellular degeneration in aged human fibroblasts: evidence for AbetaP-channel-mediated cellular toxicity

Alzheimer's disease (AD) is primarily nonfamilial or sporadic (SAD) in origin, although several genetic linkages are reported. Tissues from AD patients contain fibrillar plaques made of 39 to 43 amino acid-long amyloid beta peptide (AbetaP), although the mechanisms of AbetaP toxicity are poorly understood. AbetaP(1-40) is the most prevalent AbetaP present in the neuronal and non-neuronal tissues from SAD patients. AbetaP(1-40) toxicity has been examined mainly after prolonged incubation and correlates with the age and fibrillar morphology of AbetaP(1-40). Globular and nonfibrillar AbetaPs are released continually during normal cellular metabolism; they elevate cellular Ca(2+) and form cation-permeable channels. However, their role in cellular toxicity is poorly understood. We have used an integrated atomic force and light fluorescence microscopy (AFM-LFM), laser confocal microscopy, and calcium imaging to examine real-time and acute effect of fresh and globular AbetaP(1-40) on cultured, aged human, AD-free fibroblasts. AFM images show that freshly prepared AbetaP(1-40) in phosphate-buffered saline (PBS) are globular and do not form fiber for an extended time period. AbetaP(1-40) induced rapid structural modifications, including cytoskeletal reorganization, retraction of cellular processes, and loss of cell-cell contacts, within minutes of incubation. This led to eventual cellular degeneration. AbetaP(1-40)-induced degeneration was prevented by anti-AbetaP antibody, zinc, and Tris, but not by tachykinin neuropeptides. In Ca(2+)-free extracellular medium, AbetaP(1-40) did not induce cellular degeneration. In the presence of extracellular Ca(2+), AbetaP(1-40) induced a sustained increase in the cellular Ca(2+). Thus, short-term and acute AbetaP(1-40) toxicity is mediated by Ca(2+) uptake, most likely via calcium-permeable AbetaP pores. Such rapid degeneration does not require fibrillar plaques, suggesting that the plaques may not have any causative role.

Effects of inhaled low molecular weight heparin on airway allergic inflammation in aerosol-ovalbumin-sensitized guinea pigs

Low molecular weigh, heparin (LMWH) possesses multiple nonanticoagulant properties. In the present study, we observed its anti-airway allergic inflammatory effects by bronchoalveolar lavage in guinea pigs. Guinea pigs were sensitized by repeatedly inhaling aerosolized ovalbumin. LMWH (400 u/l, 800 u/l), dexamethasone (1.2 mg/1) or vehicle (normal saline) was inhaled for 7 days. Then the animals were sacrificed under anesthesia and then lavaged with ice-cold Hank's buffer immediately; bronchoalveolar lavage fluid (BALF) was prepared 24 h after the animals were challenged by antigen exposure. The effects of LMWH on total cell counts, absolute eosinophil counts and cell catalogues in BALF were studied; effects on the activity of eosinophil peroxidase (EPO) and the contents of histamine and eosinophil cationic protein (ECP) in BALF supernatant were detected. Our results showed that compared with the vehicle group, LMWH at 400 u/l and 800 u/1 could significantly reduce total cell counts, absolute eosinophil counts and percentage of eosinophils in BALF (P<0.05 and P<0.01, respectively); LMWH at 800 u/l markedly inhibited the activity of EPO in BALF supernatant (P<0.05); LMWH at 400 u/l and 800 u/l remarkably reduced the content of histamine in BALF supernatant (P<0.05 and P<0.01, respectively), LMWH at 800 u/l decreased the content of ECP (P<0.05) significantly. It suggested that LMWH exerted anti-airway allergic inflammatory action by inhibiting infiltration of inflammatory cells and reducing release of inflammatory mediators, as well as antagonizing their activities, and that LMWH could be developed as a potential anti-bronchial asthmatic drug.

Pyoderma gangrenosum with lung injury

A 24 year old woman with airway injury, lung infiltration and pleural effusion due to pyoderma gangrenosum is reported.

Amyloid beta protein (1-40) forms calcium-permeable, Zn2+-sensitive channel in reconstituted lipid vesicles

Amyloid beta protein (A beta P) forms senile plaques in the cerebrocortical blood vessels and brain parenchyma of patients with Alzheimer's disease (AD). The nonfamilial or sporadic AD (SAD), the most prevalent form of AD, has been correlated with an increased level of 40-residue A beta P (A beta P1-40). However, very little is known about the role of A beta P1-40 in AD pathophysiology. We have examined the activity of A beta P1-40 reconstituted in phospholipid vesicles. A combined light fluorescence and atomic force microscope (AFM) was used to image the structure of reconstituted vesicles and 45Ca2+ uptake was used as an assay for calcium permeability across the vesicular membrane. Vesicles reconstituted with fresh and globular A beta P1-40 contain a significant amount of A0 beta P and exhibit strong immunofluorescence labeling with an antibody raised against the N-terminal domain of A beta P, suggesting the incorporation of A beta P1-40 peptide in the vesicular membrane. Vesicles reconstituted with A beta P1-40 exhibited a significant level of 45Ca2+ uptake. The vesicular calcium level saturated over time, showing an important ion channel characteristic. The 45Ca2+ uptake was inhibited by (i) a monoclonal antibody raised against the N-terminal region of A beta P and (ii) Zn2+. However, a reducing agent (DTT) did not inhibit the 45Ca2+ uptake, indicating that the oxidation of A beta P or its surrounding lipid molecules is not directly involved in A beta P-mediated Ca2+ uptake. These findings provide biochemical and structural evidence that fresh and globular A beta P1-40 forms calcium-permeable channels and thus may induce cellular toxicity by regulating the calcium homeostasis in nonfamilial or sporadic Alzheimer's disease.

gamma-Radiation Synthesis of the Nanocrystalline Semiconductors PbS and CuS

The nanocrystalline semiconductors PbS and CuS were prepared by gamma-irradiation at room temperature in an ethanol system for the first time. Carbon disulfide was used as the sulfur source; lead acetate and copper chloride were used as metal ion sources. X-ray Powder Diffraction was used to characterize the products and Transmission Electron Microscopy to determine their morphology. The purity and compositions of the products were examined by X-ray photoelectron spectra. The photoluminescence property of as-prepared PbS was studied. A blue shift was observed in the PL spectra, indicating the quantum size effect on nanocrystalline PbS. Copyright 1999 Academic Press.

Effects of tetramethylpyrazine, a Chinese medicine, on plasma endothelin-1 levels during acute pulmonary hypoxia in anesthetized dogs

Our study was designed to elucidate the effects of tetramethylpyrazine (TMP), a Chinese medicine, on plasma endothelin-1 (ET-1) levels in dogs with acute pulmonary alveolar hypoxia. Anesthetized dogs were used under artificial ventilation with room air or a hypoxic gas mixture (10% O2 and 90% N2) (n = 10) for 60 min. Effects of TMP (80 mg/kg) were studied by i.v. injection of TMP before exposure to hypoxia (n = 8). Mean pulmonary arterial pressure (PAPm), systemic arterial pressure (SAPm), right atrial pressure (RAP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO), and heart rate (HR) were measured. The pulmonary vascular resistance (PVR) was calculated by the equation of (PAPm-PCWP) x 8/CO. Plasma ET-1 levels were determined in the abdominal aorta and pulmonary artery by RIA. The effects of TMP on PAP and plasma ET-1 level were evaluated by using percent increase in PAPm and the change of Da-pET (delta ET) before and after hypoxia. Both PAPm and PVR were significantly elevated 5 min after acute hypoxia over a period of 60 min, whereas CO and PCWP did not change. Plasma ET-1 levels in the abdominal aorta and Da-pET showed a significant increase. Administration of TMP significantly decreased the hypoxia-induced increase in the PAPm, PVR, and delta ET. These results suggest that TMP could be a useful therapeutic agent in the treatment of pulmonary hypertension induced by acute hypoxia through decrease of plasma ET-1 levels.

Wild-type p53 gene increases MDR1 gene expression but decreases drug resistance in an MDR cell line KBV200

Inactivation of p53 gene and overexpression of MDR1 gene are both associated with drug resistance. Previous studies have suggested that p53 gene can modulate the expression activity of MDR1 gene promoter in a promoter-CAT system. In the present study, wild-type p53 gene cDNA was introduced into a multidrug-resistant cell line, KBv200, in which endogenous p53 gene is aberrant. In wt-p53 transfected cells, the expression of MDRI gene was significantly increased, accumulation of adriamycin (ADM) was decreased, and the sensitivity to vincristine (VCR), ADM and 5-fluorouracil (5-FU) was increased compared with the parent KBv200 cells. After treatment with ADM and VCR, the p53-transfectants were more susceptible to apoptosis. The results suggest that the increase in drug sensitivity of the cells may be, at least in part, due to p53-dependent apoptosis induced by anticancer agents.

Strained DNA is kinked by low concentrations of Zn2+

A novel atomic force microscope with a magnetically oscillated tip has provided unprecedented resolution of small DNA fragments spontaneously adsorbed to mica and imaged in situ in the presence of divalent ions. Kinks (localized bends of average angle 78 degrees) were observed in axially strained minicircles consisting of tandemly repeated d(A)5 and d(GGGCC[C]) sequences. The frequency of kinks in identical minicircles increased 4-fold in the presence of 1 mM Zn2+ compared with 1 mM Mg2+. Kinking persisted in mixed Mg2+/Zn2+ electrolytes until the Zn2+ concentration dropped below 100 microM, indicating that this type of kinking may occur under physiological conditions. Kinking appears to replace intrinsic bending, and statistical analysis shows that kinks are not localized within any single sequence element. A surprisingly small free energy is associated with kink formation.

[Wild-type p53 stimulates vincristine-induced apoptosis]

Recent studies indicate that wild-type p53 can trigger cell apoptosis induced by many chemotherapeutic agents which induce DNA damage or cause disruptions of DNA metabolism, such as ADM, 5-FU, VP-16 and radiation. We introduced the wild-type p53 gene into a MDR cell line KBV200 in which the endogenous p53 was found to be rearranged. By G418 selection and Northern blot analysis, a G418-resistant clone named KBV200-p53 was obtained which continuously expressed the exogenous wild-type p53 mRNA. After treatment with Vincristine(VCR), the wild type p53-expression cells presented typical morphology characteristic of apoptosis analysed under electron and fluorescence microscopes. Flow cytometer analysis showed that the KBV200-p53 cells were more readily undergo apoptosis than their parental cells KBV200. After treatment with VCR 600 nmol.L-1 for 24 h, the apoptotic percentage of KBV200-p53 and KBV200 cells was about 42.4% and 8.4%, respectively. This result indicates that wild-type p53 stimulates VCR-induced apoptosis in KBV200 cells.

[Reversal of multidrug resistance by cyproheptadine in KBV200 cells]

The cyproheptadine (CYP) reversal of multidrug resistance (MDR) and its mechanism in KBV200 cell line were studies. MTT assay showed that CYP 15.0 mumol.L-1 could reverse vincristine, adriamycin (ADR) and etoposide resistance in KBV200 cells by a factor of 5.5, 2.0 and 1.9, respectively. CYP appeared to have no influence on the cytotoxicity of 5-fluorouracil (5-FU) and melphalan (MEL) in the cells. These results indicate that CYP is a MDR reversing agent. CYP 15.0 mumol.L-1 increased the ADR accumulation in KBV200 cells from 0.68 +/- 0.03 microgram/10(6) cells to 1.36 +/- 0.08 micrograms/10(6) cells (P < 0.01). CYP 15.0 mumol.L-1 was shown to obviously increase rhodamine 123 (R123) accumulation in and decrease its efflux from the cells. There was no change in PGP dying intensity under immunocytochemical assay and in mdr1 RNA level through slot blot analysis in the KBV200 cells exposed continuously to CYP 15.0 mumol.L-1 for 72 h. These results suggest that CYP acts by inhibiting the pumping function of PGP.

Protective role of selenium against hepatitis B virus and primary liver cancer in Qidong

High rates of hepatitis B virus (HBV) infection and primary liver cancer (PLC) are present in Qidong county. Epidemiological surveys demonstrated an inverse association between selenium (Se) level and regional cancer incidence, as well as HBV infection. Four-year animal studies showed that dietary supplement of Se reduced the HBV infection by 77.2% and liver precancerous lesion by 75.8% of ducks, caused by exposure to natural environmental etiologic factors. An intervention trial was undertaken among the general population of 130,471. Individuals in five townships were involved for observation of the preventive effect of Se. The 8-yr follow-up data showed reduced PLC incidence by 35.1% in selenized table salt supplemented vs the nonsupplemented population. On withdrawal of Se from the treated group, PLC incidence rate began to increase. However, the inhibitory response to HBV was sustained during the 3-yr cessation of treatment. The clinical study among 226 Hepatitis B Surface Antigen (HBsAg)-positive persons provided either 200 micrograms of Se in the form of selenized yeast tablet or an identical placebo of yeast tablet daily for 4 yr showed that 7 of 113 subjects were diagnosed as having PLC in the placebo group, whereas no incidence of PLC was found in 113 subjects supplemented with Se. Again on cessation of treatment, PLC developed at a rate comparable to that in the control group, demonstrating that a continuous intake of Se is essential to sustain the chemopreventive effect.

Inhibition of nitric oxide synthesis increases the secretion of endothelin-1 in vivo and in cultured endothelial cells

The aim of this study is to investigate the effects of nitric oxide, formed from L-arginine, on the production of endothelin-1 in vivo and in cultured endothelial cells. In mechanically ventilated anesthetized dogs (n = 5), mean pulmonary arterial pressure (PAPm) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FIO2 = 0.10) was 25 +/- 3.1 kPa and 68.7 +/- 10.2 kPa.s/L respectively. NG-nitro-L-arginine methylester (L-NAME), an inhibitor of nitric oxide synthase, increased the peak value of PAPm and PVR during hypoxic ventilation to 36.6 +/- 4.7 kPa and 158.4 +/- 25 kPa.s/L and its effect lasted for 2-3 hours. Meanwhile, plasma endothelin-1 level in the femoral artery increased by 20.9 +/- 7.1, 25.6 +/- 7.7, 28.6 +/- 7.9 pg/ml at the 60th, 120th, 180th minute after the injection of L-NAME respectively (P < 0.05 vs hypoxic control before the injection). In cultured endothelial cells from umbilical veins, endothelin-1 level of culture medium in control group was 35.1 +/- 5.9 pg/10(5) cells/ml (n = 9). L-NAME increased endothelin-1 level to 42.8 +/- 4.9pg/10(5) cells/ml (n = 9, P < 0.05) in case of 10(-11) mol/L and to 43.0 +/- 4.7 pg/10(5) cells/ml in case of 10(-7) mol/L (n = 9, P < 0.05). These findings indicate that endogenous nitric oxide is an inhibitory modulator of hypoxic pulmonary vasoconstriction and that nitric oxide inhibits the production of endothelin-1 in vivo and in cultured vascular endothelial cells.

[Clinical analysis of 60 cases of nosocomal pneumonias]

This article gives a clinical analysis upon 60 cases of nosocomial acquired pneumonia. All the patients are > 18 years old and the onset time ranged from 3 to 180 days after they were hospitalized with an average of 38.77 days, mostly 30 days after admission (27 cases, 49%). Among the primary diseases, the hematologic disorder (18 cases, 30%) rank the first, followed by cerebrovascular disease (9 cases, 15%) and connective tissue disease (8 cases, 13.3%), The common inducing factors are the using of corticosteroids and chemotherapy (34 cases, 58%), tracheotomy and tracheal cannula (7 cases, 11.6%). Fever occurs in 96% of the patients and cough 63.3%. The positive rate of sputum bacterial culture is 95.46%. Pseudomonas aeruginosa isolated in 25 cases (56.8%). and Klebsiella pneumoniae 18 cases (40%). P. aeruginosa shows resistant to the third generation of cefalosporins more than before, and is sensitive to ciprofloxacin and polymyxin B, while K. pneumoniae is resistant to many kinds of antibiotics, especially ampicilline and carbenicilline. The death rate of infection of P. aeruginosa is 58.33% (14/25) and that of K. pneumoniae is 60% (12/18), that of mixed infection is 66.67% (16/23).

[Pulmonary nocardia infection]

Four cases of pulmonary Nocardia infection were reported and the 22 cases reported in our country between 1980 and 1993 were analyzed together for the purpose of revealing the clinical picture of this disease in China. There was approximately a ratio of two male patients to one female (18:8) with a mean age of 40 years in this series of patients. Various underlying diseases were found as predisposing factors in 69% (18/26) of the cases. 34.5% (9/26) of the cases had a history of corticosteroid therapy. Pleural effusion was identified in 50% (13/26) of the patients. 38% (10/26) of the patients died. Patients with primary pulmonary Nocardia infection had a better prognosis than those with secondary infection. Appropriate culture media, sufficient culture time and repeated cultures were recommended to improve the positive identification rate of this special causative agent. The sulfonamides were the drugs of first choice along with prompt drainage of thoracic empyema and abscess.

Effects of calcium and calmodulin inhibitors on the abnormal proliferation of lung fibroblast

The effects of alveolar macrophage (Am phi) conditioned media from interstitial lung disease (ILD) patients on fibroblast (FB), and the role of calcium (Ca2+) blockers and calmodulin (CaM) inhibitors on the proliferation of lung FB were studied. We found that the AM phi conditioned media could stimulate FB cell proliferation and this effect could be abolished by Ca2+ blockers and CaM inhibitors. The results indicated that AM phi was in activated state in ILD and released some kinds of cytokines to stimulate the proliferation of FB, and Ca,2+ CaM were partially responsible for these actions.

[Inhibition of endogenous nitric oxide synthesis enhances acute hypoxic pulmonary vasoconstriction]

The objective of this study was to observe the role of endogenous nitric oxide, formed from L-arginine, in the regulation of acute hypoxic pulmonary vasoconstriction by inhibiting its synthesis with the false substrate NG-nitro-L-arginine methyl ester (L-NAME) in anesthetized dogs. L-NAME (1 mg/kg, 5 mg/kg, 15 mg/kg) significantly increased the mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) during hypoxic ventilation (FiO2 = 0.10) and its action lasted for 90-180 minutes. The maximum increase value (MIV) of hypoxic mPAP in three groups (4 dogs each group) is 1.1 +/- 0.2, 1.5 +/- 0.3, 1.6 +/- 0.4 kPa (1 kPa = 7.5 mmHg), respectively, while that of hypoxic PVR is 58.4 +/- 15.6, 99.3 +/- 28.8, 78 +/- 4.0 kPa.s/L (all P < 0.05 vs hypoxic control before the injection). The increase percent of hypoxic mPAP and PVR induced by L-NAME (15 mg/kg) was 45.23 +/- 5.78% and 133.2 +/- 35.22% 30 minutes after the injection, which was more remarkable than that of mPAP and PVR (18.83 +/- 5.63%, 84.13 +/- 22.67%, respectively) by L-NAME (1 mg/kg). L-arginine (0.5 g/kg) reversed the effect of L-NAME (5 mg/kg) on mPAP and PVR at hypoxic ventilation within one hour. L-NAME also markedly increased hypoxic mean arterial blood pressure at the dose of 15 mg/kg (MIV 2.7 +/- 0.7 kPa) and systemic vascular resistance at the three separate doses (MIV 354.4 +/- 99.7, 456.2 +/- 105, 361.5 +/- 70 kPa x s/L, respectively), meanwhile it remarkably decreased cardiac output and heart rate during hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effects of calcium blockers and calmodulin inhibitors on the proliferation of fibroblast in alveolar macrophage condition medium]

Alveolar macrophages (AM phi) play a key role in the process of fibrosis in many lung diseases. We investigated the effects of AM phi on the proliferation of fibroblast(FB) in various lung diseases and the influence of calcium and CaM inhibitors on those effects. AM phi conditioned media were prepared from 17 patients with interstitial lung diseases (ILD) and 13 patients with bronchogenic carcinoma (BC). In ILD group, conditioned media have stimulating effect on the proliferation of FB (P < 0.05), this effect was inhibited markedly by calcium channel blocker verapamil (2.5 x 10(-2)mg/ml, 2.5 x 10(-4)mg/ml), diltiazem (5 x 10(-2)mg/ml) and partially by CaM inhibitor chlorpromazine (2.5 x 10(-4)mg/ml). Whereas in BC group, only conditioned media from AM phi in the presence of stimulant have marked stimulating effect on the proliferation of FB, and this effect was markedly inhibited both by Ca++ channel blocker verapamil (2.5 x 10(-4)mg/ml), diltiazem (5 x 10(-4)mg/ml) and CaM inhibitor chlorpromazine (1.25 x 10(-2)mg/ml, 2.5 x 10(-4)mg/ml). We conclude that AM phi are activated in patients with ILD, but not in those with BC. The stimulating effect of cytokines secreted by activated AM phi can be inhibited by Ca blocker and CaM inhibitor. Using Ca++ and CaM blockers may be a new and promising approach in the treatment of ILD.

[Allergic granulomatous angiitis]

Allergic granulomatous angiitis (AGA) is a rare disease, which varies in clinical manifestation. The clinical course includes three stages. In the first stage most of the patients show symptoms of respiratory disease, 82 per cent of the patients has asthma and 88 per cent chronic rhinitis. In the second stage there is blood eosinophilia and in the last stage involvement of multiple organs. The etiology is not yet clear. Since 1982 four cases of AGA have been encountered in PUMC Hospital, but they were all diagnosed after 1988. All were male and aged 36-54 years. Two of them had asthma history and three enlargement of liver and proteinuria, ECG showed heart block in two, all four had neuromuscular and cutaneous involvement and elevated blood eosinophil with absolute number ranging from 1254 to 8104/mm3. Biopsy from different sites showed panangiitis associated with eosinophil infiltration and/or granulomatosis formation. All were sensitive to prednisone therapy with or without CTX after treatment the absolute eosinophil count in the four patients was less than 1000/mm3 and the symptoms alleviated.

[Pulmonary embolism: an analysis of 25 patients]

We reported 25 cases of patients with pulmonary embolism (PE) definitely diagnosed in our hospital from 1983 to 1990. Twenty-one cases of them were found in the last 5 years. This indicated that the discovery rate had increased obviously. Five of these patients were confirmed by autopsy, the other twenty cases were diagnosed by clinical manifestations combined with perfusion-inspiration lung scans and chest roentgenogram. Due to the prompt diagnosis and the appropriate use of anticoagulants, 72% of the patients survived after treatment. We suggest that all the patients with suspected PE should take perfusion-inspiration lung scans, because this is a noninvasive and reliable method. Digital subtraction angiography is necessary for some patients. Routine chest radiography, arterial blood gas analysis, intrapulmonary shunt test, deep venography or nuclide scan of lower extremities are also useful methods for the diagnosis of PE.

[Immunohistochemical investigation on the expression of glutathione S-transferases (GSTS) in lung cancer]

Paraffin-embedded tissue sections from 105 cases of human lung cancer were stained for four isozymes of GSTs by immunohistochemical PAP technique. Of the 16 cases of small cell lung cancer (SCLC) examined 14 were negative for all GST individuals, whereas one undifferentiated squamous cell type and one oat cell type treated with chemotherapy before operation were positive for GST-pi. The total positive rates of GST-pi, GSTs and GST-mu in 89 cases of non-SCLC were 75.3%, 13.5% and 9.7% separatively. Among them squamous cell carcinoma were stained positively for GST-pi in 93.5%, GSTs in 9.7% and GST-mu in 6.5%, while adenocarcinoma were in 69.7%, 15.2% and 6.1% respectively. The expression of GST-pi was weakened corresponding with the decreased degree of differentiation of cancer cell. GST-alpha was not detectable in all specimens studied. Ultrastructure location of GST-pi sites in 11 cases of non-SCLC was detected mainly on lysozymes and heterochromatin in cancer cell by transmission electronic microscopy utilizing colloidal gold labelled anti-GST-pi antibody. These results suggest that GST-pi may be an useful marker for differential diagnosis in histopathology and intrinsic sensitivity to anticancer drugs of lung cancer. GST-mu was expressed in some types of lung cancer with low positive rate and its usage as a marker needs further investigation.

[The diagnosis and therapy of 6 cases of pulmonary alveolar proteinosis]

6 cases of pulmonary alveolar proteinosis were presented. No symptom or physical finding is specific for diagnosis. The final diagnosis can only be documented by patho-morphological examination. PAS positive alcin blue negative lipoprotein in alveolar spaces is the characteristic finding. By using folley's catheter, the authors developed a modified method for pulmonary lavage, and 3 patients were treated effectively.

[Pulmonary angitis and granulomatosis]

16 patients of Wegener's granulomatosis, 4 of allergic angiitis and granulomatosis, 3 of lymphomatoid granulomatosis and 1 of necrotizing sarcoid granulomatosis were reported. In this group of different diseases, characteristic pathological manifestations are inflammatory cellular infiltration of vessel wall combined with destruction and necrosis of pulmonary parenchyma. There was little difference in their clinical features. In most of the cases, fever and systemic symptoms related to lung and extrapulmonary organs were present. Correct diagnosis of these diseases is very important, because both the prognosis and therapy are different. As for the prognosis, it ranges from benign (necrotizing sarcoidal granulomatosis) to very malignant (lymphomatoid granulomatosis). The clinical features of each illness were reviewed with emphasis on their histopathologic findings. The therapeutic effect and final outcome were followed.

Rearrangements in the second intron of the RARA gene are present in a large majority of patients with acute promyelocytic leukemia and are used as molecular marker for retinoic acid-induced leukemic cell differentiation

Chromosome 17 breakpoints in translocation t(15;17), a hallmark for acute promyelocytic leukemia (APL), have been shown to disrupt the retinoic acid receptor-alpha (RARA) gene. In this study, DNA probes around the second exon of the RARA gene showed rearrangements not previously detected. Analysis of 25 Chinese APL cases showed that RARA gene rearrangements were present in 23 cases (92%). The breakpoints were mapped unequivocally in 22 cases within the second intron of the gene. Therefore, the RARA gene rearrangement provides us with a specific marker of the disease. Simultaneous molecular and cytologic studies showed that the RARA gene rearrangements persisted during the first 2 to 3 weeks of all-trans retinoic acid (ATRA) therapy when differentiated granulocytes predominated in bone marrow, while these rearrangements disappeared after achieving complete remission. These data indicate that ATRA induces differentiation of APL cells.

A preliminary report on the intervention trials of primary liver cancer in high-risk populations with nutritional supplementation of selenium in China

The purpose of this study was to evaluate the effect of selenium (Se) in the prevention of human primary liver cancer. Three intervention trials were conducted among the residents at high risk to primary liver cancer (PLC) in Qidong county, Jiang-su province, the People's Republic of China. This area has the second highest rate of PLC in China. One trial was undertaken among the general population in a township with supplement of table salt fortified with 15 ppm anhydrous sodium selenite (Se-salt) for 5 y and the other four townships with similar PLC incidence rate served as the controls using normal table salt. The second trial was undertaken among hepatitis B virus surface antigen carriers (HBVsAg+) receiving supplement of 200 micrograms Se in form of selenized yeast (Se-yeast) daily vs placebo for 4 y. The third trial was carried out in members of families with high PLC incidence using Se-yeast (200 micrograms of Se daily) vs placebo for 2 y. The results showed that nutritional supplement of Se could reduce the PLC incidence significantly.

The retinoic acid alpha receptor gene is frequently disrupted in its 5' part in Chinese patients with acute promyelocytic leukemia

The t(15;17)(q22;q11-q21) translocation, a hallmark for acute promyelocytic leukemia (APL), has recently been shown to disrupt the retinoic acid-alpha receptor (RARA) gene localized on band 17q21. Leukemic cell DNAs from 16 Chinese patients with APL were analysed by Southern blot hybridization with probes covering the 5' and the 3' parts of the gene. In ten patients, the breakpoints were concentrated within a 5.5 kb EcoRI fragment containing part of intron 1, whereas no rearrangement was detected in the six remaining patients. Genomic amplification of the RARA gene was observed in one case. When RNA was available (six patients), abnormal-sized RARA gene transcripts were observed. Interestingly, no rearranged transcript was found in cells from a patient during a 6-day treatment with all-trans retinoic acid, while bone marrow cells still possessed the translocation.

[The profile of T-lymphocyte subsets' populations in 4 different kinds of pulmonary disorders]

By using the bronchoalveolar lavage (BAL) technique, the authors observed the distribution of T-lymphocyte subsets both in peripheral blood and BAL fluid from 4 different kinds of pulmonary disorders (44 cases). It was shown that the percentage of lymphocytes in BAL fluid was increased, the CD+3 and CD+4 cells were elevated and 4/8 ratio was also significantly elevated in the sarcoid patients (11 cases); the CD+4 cells decreased but the CD+8 cells increased and the 4/8 ratio decreased significantly in the patients of idiopathic pulmonary fibrosis (7 cases) and the patients with thoracic malignant tumors (20 cases). This special profile of T-lymphocytes indicates that the cell-mediated immune function may play an important role in the pathogenesis of the above illnesses.

Damaging role of neutrophil elastase in the elastic fiber and basement membrane in human emphysematous lung

The immunolocalization of human neutrophil elastase (HNE) in the alveolar interstitium of 6 patients with emphysema was investigated by immunochemical electron microscopy. The results showed that HNE is localized in the azurophil granules of neutrophils, and extracellularly on the elastic fibers of alveolar interstitium and basement membranes of epithelium and endothelium. The damage of elastic fibers and basement membranes could be observed. The HNE level of the alveolar interstitium was obviously elevated and closely related to the severity of emphysematous lesions as shown by measuring the mean linear intercept (MLI) in 4 emphysematous lungs with chronic bronchitis (r = 0.84). This suggests that HNE might play an important role in the pathogenesis of emphysema. Although enlarged airspace and increased MLI data were observed in 2 patients, one with asthma and the other, an elderly patient, without lung diseases, the HNE level of alveolar interstitium is much less than that of the other 4 chronic obstructive pulmonary disease patients. This implies that the mechanism of the the airspace enlargement occurring in the 2 patients may be different from that of others. These findings support the hypothesis of elastase-antielastase imbalance on the pathogenesis of pulmonary emphysema.

[Mesothelioma and mesothelial hyperplasia]

Twenty cases of pleural mesothelioma (2 localized and 18 diffuse malignant pleural mesothelioma), 6 cases of diffuse malignant peritoneal mesothelioma and 1 case of mesothelial hyperplasia were reported. The prominent clinical manifestations of malignant mesothelioma was serosal effusion. The exudate was bloody, mucinous and of high specific gravity. It contained numerous mesothelial cells. The diagnosis is difficult because mesothelial hyperplasia and other malignant tumors may mimic mesothelioma in some clinical aspects. Roentgenography, CT scan, cytology of serosal fluid and biopsy world help to establish the diagnosis of mesothelioma. Immunohistochemical features of 4 cases of mesothelioma is negative immunostaining for carcino embryonic antigen (CEA) and positive for keratin antigen. In one case ultrastructural examination showed characteristic features of epithelial mesothelioma cells. The average survival period in case of chemotherapy and/or surgical intervention in patients of this series was 31.3 months. Mesothelial hyperplasia has rather good prognosis; but the strategy of therapy may be conservative.

[The relation of vasoactive intestinal peptide and acute hypoxia]

In order to observe the effect of acute hypoxia on release of vasoactive intestinal peptide (VIP), the plasma VIP content was determined in anesthetized dogs by a specific radioimmunoassay technique during acute hypoxia. Blood gases and hemodynamics were monitored simultaneously. After inhalation of 10% oxygen. the plasma VIP levels elevated along with decrease in PaO2 and increase in pulmonary artery pressure. The plasma concentration of VIP in the portal vein increased significantly from 106 +/- 21 pg/ml before hypoxia to 173 +/- 36 pg/ml 15 minutes after the onset of hypoxia (P less than 0.01). The difference of arterio-venous VIP content increased from -3 +/- 6 pg/ml before hypoxia to +9 +/- 7 pg/ml after inhalation of 10% oxygen for 30 minutes. The results suggested that VIP was released from the gastrointestinal tract as well as from the lung in case of hypoxia and pulmonary hypertension. It is considered that the release of VIP may be an adaptive and compensatory response, promoting vasodilation and perfusion in vital organs.

[Evaluation of the causative bacteria of pneumonia in the elderly in recent years]

A study of 62 cases of elderly pneumonia (EP) in their sixties and eighties with etiologic bacteria confirmed by cultures of sputum, blood or pleural effusion was carried out Greater change of etiologic bacteria of EP in patients of eighties has been found when they were compared with those of sixties. In the group of eighties the incidence of Gram-negative bacilli increased (77%), including pseudomonas aeruginosa (48.39%), Klebsiella pneumoniae (17.35%) and Enteric coli (9.68%), while Staphylococcus aureus accounted only for 16.1%. There were 2 species of Streptococcus pneumoniae; both were mixed with other bacteria in cultures. In patients of eighties the etiologic agents isolated from pneumonia were more resistant to many common antibiotics. The above mentioned results suggest that the diagnosis of etiology of pneumonia in the elderly should be emphasized.

[Multiple primary bronchial carcinoma. A case report of three separate synchronous primary cancers and a review of literature]

Fibreoptic bronchoscopy was performed in 677 patients with primary bronchial carcinoma during a period from October 1978 to January 1988. In one of them three separate synchronous bronchial carcinomas were found in the lungs. Two of these tumours were radiographically occult. The diagnoses of squamous cell carcinoma of the lung were verified histologically by materials obtained at fibreoptic bronchoscopy. This finding emphasizes the importance of careful bronchoscopic examination of the whole bronchial tree before surgical treatment of lung cancer. The literatures of 41 cases with multiple primary bronchial carcinoma were reviewed.

[Congenital pulmonary arteriovenous fistula. A report of 8 cases]

In 8 cases of A-V fistula the clinical manifestations were found to be exertional cyanosis, dyspnea and digital clubbing. Those patients might also have chest pain, tachycardia, telangiectases, polycythemia and severe hypoxemia. Murmur might be found over the surface area of the lesion. Chest X-ray examination revealed solitary circumscribed lesion in five of them and multiple lesions in two. X-ray findings were similar to bronchiectasis in one. The diagnosis and differential diagnosis of this lesion were discussed. Lung scan with technetium macroaggregated albumin was used to detect the A-V fistulae. Six cases were operated on and successful resections of the lesions were carried out in 4. One died right after the operation. In one case the larger fistula was resected, but some smaller fistulae remained and finally therapeutic embolization was carried out. No complication was encountered.

Chemoprevention trial of human hepatitis with selenium supplementation in China

A three-year study has been conducted for prevention of infectious hepatitis with supplementation of table salt fortified with 15 ppm anhydrous sodium selenite to the general population of 20,847 persons in a township M.Z. at Qidong County, Jiangsu Province, China. The results showed that the incidence of virus hepatitis infection in the test township was significantly lower than that of controls provided with normal table salt. The incidence rate of infectious hepatitis in the treated township M.Z. was 1.20 and 4.52 per 1,000, whereas the average incidence in the 6 surrounding control townships was 2.96 and 10.48 per 1,000 in 1986 and 1987, respectively. The incidence of hepatitis B surface antigen (HBsAg+) was 13.2% vs 19.23% for males and 10.42% vs 12.24% for females in the supplemented vs nonsupplemented neighboring township, respectively. Epidemiological studies have demonstrated that a low grain Se content is associated with a high regional incidence of hepatitis B virus infections.

Whole-cell clamp study of Xenopus embryonic cholinergic neurons

Whole-cell clamped myoballs are placed into direct visible contact with the growth cones of isolated neurons in embryonic Xenopus culture to serve as probe of acetylcholine (AcCHo) release in order to determine whether these neurons are cholinergic or not. Using a G omega -seal, whole-cell recording method, the electrophysiological properties of these identified cholinergic neurons are studied. It is found that these embryonic neurons, like adult frog motor neurons, exhibit repetitive firings in a certain embryonic developing stage. A development of repetitive firings is observed simultaneously. Tracing the development of one neuron, we find that the development of repetitive firing is completed at the 48th h after fertilization. Tetrodotoxin (TTX) which blocks Na+ channels can abolish all firings; and tetraethyl ammonium chloride (TEA), the blocker of K+ channels, reverses this development, i.e. it makes the repetitive firings disappear again. These data show that the nature of the development of repetitive firings is the development of K+ channels.

[Carcinoembryonic antigen assay in serum and pleural effusion of pulmonary malignancies and benign lesions]

Levels of carcinoembryonic antigen(CEA)in the serum and pleural effusion in malignancies (65) and benign (25) of lung were determined. There are 20 cases of adenocarcinoma, 16 undifferentiated carcinoma, 7 squamous cell carcinoma, 4 alveolar carcinoma, 12 unclassified carcinoma, 1 polymorphous adenoma, 1 mesothelioma, 1 thymoma, 1 metastatic cancer from kidney and 2 metastatic breast cancer. In the benign lesions, there are 20 tuberculosis, 2 heart failure, 1 pneumonia, 1 empyema and 1 cirrhosis. The mean of the CEA level in the serum of lung cancer group was 12.63 ng/ml as compared with that of the tuberculosis group, 3.01 ng/ml (P less than 0.01). The level of CEA in pleural fluid in the lung cancer group was 57.30 ng/ml as compared with that of tuberculosis group, 5.55 ng/ml (P less than 0.01). The content of CEA in the serum and pleural fluid in lung cancer group was remarkably different (P less than 0.01). CEA level in the serum of adenocarcinoma is the highest (mean 15.51 ng/ml). If we set 5 ng/ml as the margin of normal CEA level in serum, the positive rate for cancer would be 54.2%. It is suggested that the margin of CEA normal value be set at 10 ng/ml for the pleural fluid. Higher readings may imply cancer.