Immunolocalization of beta 1 integrins in human gingival epithelium and cultured keratinocytes

Beta 1 integrins are cell surface receptors for extracellular matrix binding. We have recently shown that these receptors may also play a role in cell-cell binding of human epidermal keratinocytes. In this study we used immunofluorescence and confocal laser scanning microscopy to localize beta 1 integrins in frozen sections of human gingiva and cultures of human gingival keratinocytes. The results show that beta 1 integrin polypeptides, localized by monoclonal and polyclonal antibodies, were detected mainly in the basal layer of the keratinized epithelium. There was also scattered staining in connective tissue fibroblasts, nerves, and blood vessel walls. In the basal layer, the integrins were found around the entire periphery of the basal keratinocytes. Furthermore, confocal laser scanning microscopy (CLSM) revealed that most of the staining was in fact localized in dot-like structures at the lateral cell membranes of neighboring basal cells. In cultured human gingival keratinocytes maintained in low calcium (0.15 mM) conditions beta 1 integrins were localized in several different structures: trails which were left behind when the cells moved in culture, dots underneath the cells, around the nucleus, and in cell-cell contacts. The trails were also found to contain fibronectin and type IV collagen but not laminin. Switching the keratinocytes to high calcium (1.2 mM) conditions induced the formation of cell-cell contacts which were strongly positive for beta 1 integrins. No fibronectin or type IV collagen was found in cell-cell contact sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Isolation and characterization of bovine gingival proteoglycans versican and decorin

1. We have isolated, chemically and immunologically characterized versican and decorin from bovine gingiva. 2. Versican was of large molecular weight and the molecular size of the core protein was estimated to be greater than 200 kDa. 3. The glycosaminoglycan chains were susceptible to chondroitinase ABC and N-linked oligosaccharides were present on the protein core of the molecule. 4. Immunological studies provided evidence that a hyaluronic acid binding region was present in the core protein of versican. 5. The overall structure was similar to that of versican isolated from bovine sclera. 6. Decorin had a molecular weight of 102 kDa and its glycosaminoglycan chain was completely digested by specific glycosidases. 7. The partially deglycosylated core protein had a molecular weight of 55 kDa and N-linked oligosaccharides were present on the molecule.

Cocaine and metabolite concentrations in the hair of South American coca chewers

Hair samples obtained from South American Indians who were identified as daily chewers of coca leaves were analyzed by a sensitive gas chromatography/mass spectrometry (GC/MS) method for cocaine, benzoylecognine (BE), and ecognine methyl ester (EME). The mean cocaine concentration in the hair of these five subjects was 15.2 ng/mg hair +/- 11.0 (range = 1.0-28.9 ng/mg), mean BE concentration was 2.8 +/- 1.6 ng/mg hair (range = 0.3-4.4 ng/mg hair), and mean EME concentration was 1.6 +/- 1.7 (range = 0.0-4.4 ng/mg hair). The finding that cocaine was present at approximately 5 times higher concentration than BE and approximately 12 times higher than EME is surprising in light of the much longer plasma half lives of these metabolites. Washing the hair before analysis with 1% dodecyl sulfate, methanol, and distilled water reduced the concentration of cocaine in the hair but also reduced the concentrations of the metabolites. These data suggest that factors other than the drug concentration in blood may be important in determining the amount of drug incorporated into hair.

A longitudinal study of lung function in jute processing workers

A 5-y follow-up study of pulmonary function was conducted in 1982 and in 1987 for 50 current and retired jute-processing workers who had been employed for more than 10 y in a jute mill in China. Control subjects, who had no history of dust or gas exposure, were selected from a paper-packing plant in the same city. Forced expiratory maneuvers were conducted in the same manner in both 1982 and 1987. The jute workers' pulmonary functions, i.e., forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and forced expiratory flow (FEF25-75%), were more compromised than were pulmonary functions in the controls for the same 5-y period; however, only the increased incidence of abnormal FEV1.0s in jute workers was statistically significant. Male jute workers had significantly higher annual decrements of FVC, FEV1.0, and FEF25-75% than did control workers. Regression analysis indicated that in 1987, predicted values of FEV1.0 and FEF25-75% for the jute workers were related to years of employment. Our results suggest that long-term exposure to jute dust could produce chronic loss of lung function.

[Elimination of fat emulsions of various concentrations from the blood. Observational study in the intravenous administration of Lipovenös 10% and 20% in premature infants with very low birth weight]

Within the scope of an observation study 40 premature low birth weight infants requiring parenteral nutrition received either 10% or 20% lipid emulsions (Lipovenös) for 7 days. The 10% lipid emulsion differs from the 20% lipid emulsion in the higher phospholipid/triglyceride-ratio (0.06 resp. 0.12). Lipid infusion was commenced at 0.5 g triglyceride/kg/24 hours and increased steadily to 2 g triglyceride/kg/24 hours. The aim of the study was to compare the effects of the two intravenously administered lipid emulsions on serum clearance. The serum concentrations of triglyceride and cholesterol did not change significantly during the infusion with 20% Lipovenös. Significant increases in the triglyceride and cholesterol content were observed only in the serum of the patients who were given the 10% Lipovenös. The reduced lipid serum clearance is attributable to the higher content of phospholipids in the 10% lipid emulsion. With regard to the risk of high cholesterol concentrations and an abnormal LPX serum accumulation, administration of 20% lipid emulsion is preferable to 10% lipid emulsion, also during the neonatal period.

Simultaneous quantitation of cocaine and its major metabolites in human hair by gas chromatography/chemical ionization mass spectrometry

A sensitive method for the simultaneous analysis of cocaine, benzoylecgonine (BE), and ecgonine methyl ester (EME) in human hair by gas chromatography/chemical ionization mass spectroscopy (GC/CIMS) is described. Hair samples are cut into 1-cm sections, washed with 1% sodium dodecylsulfate, rinsed with deionized water and methanol, and then digested overnight in a solution containing Tris buffer, sodium dodecylsulfate, Proteinase K, and dithiothreitol. Digested hair samples are extracted with Bond Elut Certify solid-phase extraction columns, derivatized with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), and analyzed by GC/CIMS using isobutane as reagent gas. This method is quantitative, does not cause degradation of cocaine, and requires as little as 5 mg of hair. Analysis is performed on a Finnigan ITS-40 ion trap mass spectrometer interfaced with a Varian 3400 gas chromatograph equipped with a Model 1075 split/splitless injector and a J&W DB-5 capillary column. Full scan spectra are used for identification of cocaine and its metabolites. Quantitation is based on peak area ratios of the MH+ ions, as follows: 304 for cocaine, 404 for BE-TBDMS, 314 for EME-TBDMS, and 340 for the internal standard, difluorococaine. This method can be used to quantitate cocaine at concentrations of 0.1 to 100 ng/mg hair. The coefficients of variation (%CV) at a drug concentration of 1 ng/mg hair are 10.3, 16.3, and 27.7% for cocaine, BE, and EME, respectively.

Increased airways responsiveness in swine farmers

A respiratory questionnaire, pulmonary function tests, and an examination of airways responsiveness were conducted on 20 swine farmers and 20 control subjects. The swine farmers represented almost the complete work force from 13 Hutterite colonies and had worked in confinement buildings with more than 2,000 swine (3,270 +/- 1,221 swine) for at least four hours (6.6 +/- 1.8 hours) per day for more than two years (10.5 +/- 7.5 years). The control subjects were randomly selected from outdoor city workers from the city of Saskatoon and were matched for gender, age (+/- 2 years), and smoking status. Eleven swine farmers (55 percent) had chronic cough, compared with three (15 percent) of the control subjects (p less than 0.01). Eight (40 percent) of the swine farmers had symptoms of wheezing, compared with three (15 percent) of the control subjects (p less than 0.05). The FEV1 was significantly lower in swine farmers (97.2 +/- 11.5 percent predicted) than in control subjects (106.0 +/- 12.0 percent of predicted) (p less than 0.05). Airways responsiveness was measured by methacholine challenge with doubling concentrations ranging from 0.25 to 256 mg/ml. The provocation concentrations resulting in a reduction of 10 percent (PC10) and 20 percent (PC20) in FEV1 were lower in swine farmers than in control subjects (PC10, 77.2 +/- 78.8 mg/ml vs 180.8 +/- 96.5 mg/ml; p less than 0.01; and PC20, 154.5 +/- 99.9 mg/ml vs 229.6 +/- 66.8 mg/ml; p less than 0.05). Twelve swine farmers (60 percent) had PC20 of less than 256 mg/ml, compared with three (15 percent) of the control workers (p less than 0.01). Fewer swine farmers demonstrated atopy as measured by skin prick tests than did control workers (21 percent vs 56 percent; p less than 0.05). These findings suggested that occupational exposure in swine confinement buildings is associated with mild increases of nonspecific, nonatopic airways responsiveness in swine farmers.

CDC6 mRNA fluctuates periodically in the yeast cell cycle

Using cultures synchronized by two independent procedures, alpha-factor arrest and centrifugal elutriation, we have investigated the expression of the Saccharomyces cerevisiae CDC6 gene through the cell cycle. Our results show that the CDC6 gene is periodically expressed in the yeast cell cycle. The level of CDC6 transcripts increases in late G1, reaching a peak (approximately 10-20-fold over the initial level) at about the G1/S phase boundary. The peak of CDC6 mRNA was observed to overlap or slightly precede that of the CDC8 message, and to obviously precede that of the histone H2A message by some 25 min. Unlike histone H2A mRNA, the CDC6 mRNA as well as CDC8 mRNA were not affected by hydroxyurea treatment. These results suggest that regulation of H2A mRNA is different from that of CDC6 or CDC8. We have studied the 5'-flanking regions of CDC6 and other cell cycle-regulated genes. DNA sequence analysis of the CDC6 promoter revealed two sequences, 5'-C/GACGCGNC/G-3' and 5'-PuGNAGAAA-3' (where Pu is a purine, and N is any nucleotide), which are repeated three times each. Similar sequence elements have also been found among several cell cycle-regulated genes, including the CDC8 gene, but are not found upstream of histone genes. The possible significance of these elements is discussed.

Zn(II)-phthalocyanine as a photodynamic agent for tumours. II. Studies on the mechanism of photosensitised tumour necrosis

The mechanism of tumour necrosis photosensitised by liposome-delivered Zn(II) phthalocyanine (Zn-Pc) has been studied in mice bearing a transplanted MS-2 fibrosarcoma. Ultrastructural analyses of tumour specimens obtained at different times after red light-irradiation (300 J cm-2, dose-rate 180 mW cm-2) indicate an early (3 h) photodamage of malignant cells especially at the level of the mitochondria and rough endoplasmic reticulum. The cellular damage becomes more evident between 6 h and 15 h after photodynamic therapy. On the other hand, the capillaries supplying the tumour tissue are modified at a much slower rate and appear to be severely damaged only after 15 h from irradiation, when the whole tissue becomes necrotic. Occasionally, mildly damaged capillaries are observed even at 72 h after irradiation. These findings support the hypothesis that low density lipoproteins (LDL) play a major role in the delivery of Zn-Pc to the tumour tissue; the photosensitiser is released specifically to malignant cells as a consequence of a receptor-mediated endocytosis of LDL.

Relationship between airways responsiveness and the development of chronic obstructive pulmonary disease

The idea that increases in airways responsiveness--either as a result of exposure to cigarette smoke and/or pre-existing increases in bronchial responsiveness, possibly genetically mediated--might be causal in the pathogenesis of the development of COPD in cigarette smokers presents an attractive hypothesis. The fact that a relatively small proportion of cigarette smokers develop COPD begs for specific susceptibilities as an explanation of selective pathogenesis. In our view, the evidence for modest increases in airways responsiveness in cigarette smokers who do not have asthma or allergies is convincing. Such increases in bronchial responsiveness are modest when compared to patients with asthma and may have a different mechanism. However, the demonstration by Verma et al that two types of patients with cigarette smoke-induced COPD, "bronchitis" patients and "emphysematous" patients, have virtually identical alterations in bronchial responsiveness, and that these alterations appear to be a function of airways caliber, has led us to believe that the changes in airways tone in patients with COPD may be reflective more of changes in airways geometry imposed by the development of disease rather than a measurement of a risk factor in the development of COPD. Of the epidemiologic studies that have emerged throughout the 1980s, problems of possible inclusion of asthmatic subjects in the study groups and of baseline airflow rates as a function of bronchial responsiveness have limited the ability of data to implicate increases in airways responsiveness as a risk factor in the development of COPD.(ABSTRACT TRUNCATED AT 250 WORDS)

[Biological characteristics of Psoralea corylifolia L]

A study has been made on the biological characteristics of Psoralea corylifolia under general cultivating conditions. To search for the laws of growth and development so as to facilitate further studies on the cultivating techniques for higher production of Psoralea corylifolia.

[Anti-inflammatory effect of aconitines]

Aconitines are the total alkaloids isolated from the main root of Aconitum carmichaeli. They have marked suppressive effect on the swelling of rat's hind paw induced by injections of fresh egg protein, carrageenin, histamine and 5-HT, on the mouse's ear oedema induced by bimethylphenyl, on the exudate and proliferation of granulation tissue of granuloma pouch induced by croton oil, on the leukocyte migration and on the contents of PGE in the exudate of the swelling hind paw induced by injecting carrageenin. Aconitines have been found useful in inhibiting significantly such immune inflammations as reversible passive Arthus reaction, rat's delayed skin hypersensitivity and adjuvant arthritis. They have also a noticeable analgesic effect.

Liposome- or LDL-administered Zn (II)-phthalocyanine as a photodynamic agent for tumours. I. Pharmacokinetic properties and phototherapeutic efficiency

The pharmacokinetics of Zn-phthalocyanine (Zn-Pc) in mice bearing a transplanted MS-2 fibrosarcoma has been studied using dipalmitoyl-phosphatidylcholine (DPPC) liposomes and low density lipoproteins (LDL) as drug delivery systems. LDL induce a higher Zn-Pc uptake by the tumour and improve the selectivity of tumour targeting as compared to DPPC liposomes. Experimental photodynamic therapy (PDT) of the MS-2 fibrosarcoma has been performed using liposome-delivered Zn-Pc and the efficiency of tumour necrosis has been measured following four different irradiation protocols. We found that Zn-Pc doses as low as 0.07-0.35 mg kg-1 are sufficient for inducing an efficient tumour response that is linearly dependent on the injected dose. The amount of Zn-Pc in the tumour decreases very slowly as a function of time, hence PDT gives satisfactory results even if performed at relatively long time intervals after administration.

The prevention of silicosis and prediction of its future prevalence in China

We studied the effects of preventive and therapeutic interventions on the 18-year cumulative incidence of silicosis of 26,603 dust-exposed workers in seven Chinese mines and industrial plants. Cumulative silicosis incidence decreased from 36.1 percent in workers employed before 1950 to 1.5 percent in workers employed after 1960. From the 1950s to 1970s, eight-year cumulative incidence of tuberculosis decreased from 54.7 percent to 16.7 percent and case fatality of silicosis patients dropped from 53.9 percent to 18.3 percent. From 1950s to 1980s, the average age at the detection of silicosis increased from 41.3 to 52.7 and the average survival time of silicosis patients prolonged from 2.0 to 12.2 years. Workers over age 40 who began exposure to dust before 1960 will be the main source of new silicosis patients in future. Most expected new cases of silicosis will occur within the next 15 years. The silicosis population will remain unchanged for the next 20 years and will decrease dramatically after 25 years. There will be few silicosis patients in 30 years and new cases of silicosis will be difficult to find in 45 years. These results show that the preventive and therapeutic actions against silicosis in China have been effective.

Respiratory symptoms and lung function in jute processing workers: a primary investigation

This paper presents the results of an investigation of respiratory symptoms and lung function of 404 workers who had been exposed to jute dust in a jute mill. Measurement of total dust concentration and analysis of dust composition were also conducted. Most workers in the jute mill were exposed to jute dusts containing less than 5% silica, whereas a few workers were exposed to dusts containing approximately 10-15% silica. Male smokers and nonsmokers in the dust-exposed group had a higher prevalence of cough and chest tightness compared with those in the control group. Among dust-exposed workers, female nonsmokers had a significantly higher prevalence of cough, chronic bronchitis, chest tightness, and dyspnea than those in the control group. Lung function tests showed that dust-exposed workers had a greater incidence of abnormal lung function than did control workers, as measured by percentage of predicted forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1.0), and FEV1.0/FVC. Dust exposure was the main cause of respiratory symptoms and abnormal values of FEV1.0, but both cigarette smoking and dust exposure contributed to the abnormal values reported for FEV1.0.

Molecular cloning of Saccharomyces cerevisiae CDC6 gene. Isolation, identification, and sequence analysis

The CDC6 gene product is required for entering the S phase of the cell cycle in Saccharomyces cerevisiae. It has been isolated on recombinant plasmids by selection for complementation of temperature-sensitive alleles with a yeast genomic library. The entire complementing activity is carried on a 1.8-kilobase chromosomal DNA fragment, as revealed by deletion mapping. Northern blotting shows that the size of the CDC6 mRNA is about 1.7 kilobases. A Southern blot of yeast chromosomes which were separated by the field inversion gel electrophoresis method indicates that the isolated DNA fragment is derived from chromosome X. The locus from which the clone was derived was marked by integration with a nutritional marker and found by meiotic mapping to cosegregate with CDC6. Thus, we conclude that we have isolated the authentic CDC6 gene. Nucleotide sequence analysis of the CDC6 gene has revealed an open reading frame that encodes a protein with Mr = 57,969. There are five potential Asn-X-(Ser/Thr) glycosylation sites and a highly conserved nucleotide-binding site in the CDC6 sequence. Although computer surveys indicate overall sequence homology between S. cerevisiae CDC6 protein and Saccharomyces pombe CDC10 START protein, they may not be functionally equivalent as evaluated by the complementation assay.