Identification of protease(s) capable of further degrading native 3/4- and 1/4-collagen fragments generated by collagenase from native type I collagen in human neutrophils

The role of human neutrophil proteases in the further degradation of the native triple-helical characteristic cleavage products 3/4- and 1/4-collagen fragments generated by neutrophil interstitial collagenase from native type I collagen was studied. Purified human neutrophil collagenase did not further degrade the characteristic collagen fragments whether they were in triple-helical (native collagen) or random-coil (gelatin) conformation. Neutrophil extract treated with 1 mM phenylmercuric chloride (PMC) degraded native type I collagen at +37 degrees C producing multiple protein bands. Neutrophil extract at +18 degrees C in the presence of the serine protease inhibitors phenylmethylsulfonyl fluoride and banzamidine did not degrade native type I collagen. Inclusion of PMC to active latent collagenase caused neutrophil extract to degrade native type I collagen to 3/4- and 1/4-fragments. In addition, native 3/4- and 1/4-fragments were further degraded in a time-dependent manner by PMC-treated neutrophil extract. Both native 3/4- and 1/4-collagen fragments were degraded by specific rather than by multiple cleavage. Further fragmentation was inhibited by divalent cation chelators EDTA and 1,10-phenanthroline. The results indicate the presence of latent metalloprotease(s), as distinct from collagenase, gelatinase and serine proteases, that are capable of further degrading by specific cleavage both native 3/4- and 1/4-collagen fragments generated by collagenase in human neutrophils. The enzyme(s) may augment the action of collagenase and other neutral proteases in connective tissue destruction associated with the etiopathogenesis of periodontal diseases.     

Evaluation of sister chromatid exchange as an indicator of sensitivity to N-ethyl-N-nitrosourea-induced carcinogenesis in rats

Sister chromatid exchange (SCE) frequencies in peripheral lymphocytes are a frequently used endpoint to indicate exposures to genotoxins in groups of humans. The aim of this study was to ascertain, in an experimental design, whether or not SCE rates have any association with the risk of cancer at the individual level in rats exposed to a known carcinogen. Individual SCE rates were determined in three consecutive analyses in cultured blood lymphocytes of 50 adult male Wistar rats. Analyses were done before as well as 24 hr and 7 days after a single intraperitoneal administration of 0, 25, 50, or 75 mg/kg of N-ethyl-N-nitrosourea (ENU). The animals were followed until death; also, the relationship between SCEs and carcinogenic outcome, i.e., the presence or absence of tumors, and their latency period were examined. ENU significantly decreased the life expectancy of the rats. The tumor types most clearly associated with ENU treatment were various gliomas and thyroid-gland and testicular tumors. ENU induced a moderate (maximally 1.6-fold) increase in the mean frequency of SCEs/cell at both sampling times after treatment. The effect was somewhat more pronounced 1 day rather than 1 week after treatment. The mean SCE rates in rats with ENU-specific cancers or in animals with early or multiple tumors did not differ from those in animals that survived no less than 65 weeks or longer without developing tumors. In ENU-treated animals with tumors, no relationship was found between the mean SCE rate and survival time. It is concluded that in outbred Wistar rats the SCE response in cultured lymphocytes does not indicate individual susceptibility to the carcinogenic action of ENU. On a group basis, however, animals with high SCE rates were shown to have increased risk of cancer.     

Activities and ways of organizing better occupational health and safety in small workplaces: special focus on information

Information is needed in all activities aiming at the development and improvement of working conditions. The information and communication technology has made it possible to have information available 24 h a day, 360 d a year. The administrative structures in various countries also call for more information steering at the workplace level. This means that more web-based and other materials for small enterprises are needed in all countries in order to improve safety and health of the workers. Four different approaches to improve workplace level activities are described here to provide models for others to modify them to their local conditions. The networking of small workplaces supports the development of their safety and thereby also their productivity and possibilities to offer jobs also in the future.     

Acute cardiovascular responses in preterm infants at 34–39 weeks of gestational age

Background

Premature infants demonstrate immature physiological control mechanisms; however their acute cardiovascular control has not yet been widely studied.

Aim

The aim of this study was to analyze heart rate (HR) and blood pressure (BP) control in preterm infants.

Subjects

Twenty preterm infants with a mean gestational age of 31 ± 2.4 (26–34) weeks at birth were evaluated at a gestational age of 36 ± 1.5 (34–39) weeks. Results were compared to twenty, healthy, full-term, control infants studied at the age of 12 ± 3 weeks.

Outcome measures

HR and BP responses to 45° head-up tilt and side motion tests during non-rapid eye movement sleep were analyzed. In addition, HR responses to spontaneous arousals from non-rapid eye movement sleep were evaluated.

Results

Preterm infants showed significantly smaller initial HR and BP responses compared with controls in head-up tilt (HR p = 0.0005, systolic BP p = 0.02, diastolic BP p = 0.01) and side motion tests (HR p = 0.002, systolic BP p < 0.0001, diastolic BP p < 0.0001). Furthermore, in tilt tests, preterm infants presented with greater intersubject variability in BP responses than controls (systolic BP p = 0.009, diastolic BP p = 0005). Preterm HR responses to spontaneous arousals were similar to controls.

Conclusions

This study indicates immature vestibulo-mediated cardiovascular control in preterm infants compared with term infants. This is seen as attenuated BP responses to side motion test and more labile acute BP control to postural challenge.     

Lack of MMP-9 expression is a marker for poor prognosis in Dukes’ B colorectal cancer

Background

Matrix metalloproteinases (MMPs) play a role in cancer progression by degrading extracellular matrix and basement membranes, assisting in tumour neovascularization and in supporting immune response in cancer.

Methods

We studied the prognostic value of immunohistochemical expression of MMP-2, MMP-8, and MMP-9 in a series of 619 colorectal cancer patients using tissue microarray specimens.

Results

Of the samples, 56% were positive for MMP-2, 78% for MMP-8, and 60% for MMP-9. MMP-9 associated with low WHO grade (p?<?0.001). In univariate analysis of Dukes’ B tumours, MMP-9 negativity associated with poor survival (p?=?0.018), and MMP-9 positivity was an independent prognostic marker in multivariate analysis of these tumours (p?=?0.034).

Conclusion

Negative MMP-9 expression can predict poor prognosis in Dukes’ B colorectal tumours and may prove useful for identifying patients, who should be offered adjuvant treatment.

     

Oral rinse MMP‐8 point‐of‐care immuno test identifies patients with strong periodontal inflammatory burden

Oral Diseases (2010) 17 , 115–122 Objective: To determine whether oral rinse matrix metalloproteinase (MMP)‐8 levels, measured by three different methods, tissue inhibitor of matrix metalloprotease‐1 (TIMP‐1) levels and elastase activity differentiate subjects with different periodontal condition; and second, to find out if MMP‐8 levels were comparable among the methods used. Methods: MMP‐8 levels were analysed with an immunofluorometric method (IFMA), dentoELISA and commercial ELISA. Also TIMP‐1 levels and elastase activity were measured. For statistical analysis 214 study subjects were categorized into four groups, specified by the presence and number of moderate (4–5 mm) and deep (≥6 mm) periodontal pockets, and bleeding on probing percentage. Results: MMP‐8 levels especially measured by dentoELISA and adjusted to the number of teeth per subject differentiated the study group with strong periodontal inflammatory burden from groups with lower levels. This was also verified with receiver operating characteristic ( ROC) analysis. Elastase activity associated with higher IFMA and dentoELISA MMP‐8 levels. IFMA MMP‐8/TIMP and dentoELISA MMP‐8/TIMP‐1 tended to be higher with the increasing level of periodontal inflammatory burden. TIMP‐1 levels decreased with increasing age. Conclusions: Oral rinse MMP‐8 together with TIMP‐1 analysis may have potential in complementary periodontal diagnostics. dentoELISA can be applied in quantitative oral rinse chair side biomarker diagnostics.     

Familial clustering of beta-cell autoimmunity in initially non-diabetic children

BACKGROUND: Type 1 diabetes is characterised by familial aggregation. We set out to explore whether beta-cell autoimmunity, which is considered to precede clinical disease, also shows familial clustering. METHODS: Tests for HLA DQB1 alleles (*02, *0301, *0302, *0602) and islet cell autoantibodies (ICA) were performed on 5836 children from 2283 families. When a child tested positive for ICA, all his/her previous or subsequent samples that were available were also tested for insulin autoantibodies (IAA), antibodies to glutamic acid decarboxylase (GADA) and antibodies to the IA-2 protein (IA-2A). RESULTS: Forty-four families were observed to have two or more children positive for at least ICA. This proportion (1.9%) was almost five times higher than expected (0.4%; p < 0.001). The frequency of multiple (>/=2) autoantibodies also showed familial aggregation, the observed proportion (0.39%) being three times that expected (0.13%; p < 0.001). In 72.7% of the families with at least two ICA-positive siblings, the children with autoantibodies had the same HLA DQB1 genotype. The median age difference between the ICA-positive children within the same family was 3.3 years (range 0.0-10.5 years), and the median time interval in the appearance of ICA within the family was 1.6 years (range 0.0-3.2). CONCLUSIONS: beta-cell autoimmunity, as defined by the appearance of ICA, demonstrates familial aggregation, although the antibodies do not appear in close temporal proximity or at an identical age within the same family. The HLA-DQB1 genotypes are more often identical in siblings with autoantibodies than in other siblings.     

Soluble adhesion molecules in young children with signs of beta-cell autoimmunity--prospective follow-up from birth

BACKGROUND: This study aimed at evaluating the relationship between the circulating concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) and sL-selectin and the appearance of beta-cell autoimmunity, and at assessing whether these molecules could assist in the identification of environmental factors implicated in the immune process damaging the pancreatic beta-cells. METHODS: Serum levels of soluble adhesion molecules were measured with enzyme-linked immunosorbent assays over the first 2 years of life in 65 children seroconverting to positivity for autoantibodies and 65 control children, all with HLA-conferred susceptibility to type 1 diabetes (T1D). RESULTS: The total integrated concentrations of soluble adhesion molecules were comparable between the two groups. The autoantibody-positive children tended to have higher sL-selectin concentrations during the 3-month seroconversion (SC) period than did the control children during the corresponding period (P = 0.07), the difference being significant (P = 0.03) after excluding subjects with signs of a concurrent enterovirus infection. Autoantibody-positive children had higher concentrations of sL-selectin in the 3-month period when an enterovirus infection was detectable than did the control children (P = 0.018). No significant difference could, however, be seen after excluding the children with concomitant seroconversion to autoantibody positivity. CONCLUSIONS: Elevated concentrations of sL-selectin are temporally associated with seroconversion to autoantibody positivity suggesting that leukocyte activation might coincide with the appearance of beta-cell autoimmunity. Early-onset progressive beta-cell autoimmunity, on the other hand, is not reflected in overall increased concentrations of soluble adhesion molecules in the peripheral circulation during the first 2 years of life in children carrying increased HLA-conferred disease susceptibility. Enterovirus infections (EVIs) are not independently associated with increased circulating sL-selectin concentrations in young children with enhanced HLA-conferred susceptibility to T1D.