The Doa4 deubiquitinating enzyme is functionally linked to the vacuolar protein-sorting and endocytic pathways

The Saccharomyces cerevisiae DOA4 gene encodes a deubiquitinating enzyme that is required for rapid degradation of ubiquitin-proteasome pathway substrates. Both genetic and biochemical data suggest that Doa4 acts in this pathway by facilitating ubiquitin recycling from ubiquitinated intermediates targeted to the proteasome. Here we describe the isolation of 12 spontaneous extragenic suppressors of the doa4-1 mutation; these involve seven different genes, six of which were cloned. Surprisingly, all of the cloned DID (Doa4-independent degradation) genes encode components of the vacuolar protein-sorting (Vps) pathway. In particular, all are class E Vps factors, which function in the maturation of a late endosome/prevacuolar compartment into multivesicular bodies that then fuse with the vacuole. Four of the six Did proteins are structurally related, suggesting an overlap in function. In wild-type and several vps strains, Doa4-green fluorescent protein displays a cytoplasmic/nuclear distribution. However, in cells lacking the Vps4/Did6 ATPase, a large fraction of Doa4-green fluorescent protein, like several other Vps factors, concentrates at the late endosome-like class E compartment adjacent to the vacuole. These results suggest an unanticipated connection between protein deubiquitination and endomembrane protein trafficking in which Doa4 acts at the late endosome/prevacuolar compartment to recover ubiquitin from ubiquitinated membrane proteins en route to the vacuole.

The aetiology and epidemiology of clavicular fractures. A prospective study during a two-year period in Uppsala, Sweden

In a prospective study, the age- and gender-specific incidence and features of clavicular fractures were studied during 1989 and 1990. The population at risk consisted of about 200,000 individuals aged 15 or above in the county of Uppsala, Sweden. There were 187 clavicular fractures in 185 patients corresponding to an annual incidence of 50/100,000 (males 71/100,000, women 30/100,000). Males were significantly younger and sustained comminuted fractures more often than women. The fracture incidence decreased with age in both genders, although the reduction was significant only in men. Bicycle accidents most frequently caused clavicular fractures in both genders, whereas sports activities were significantly more common in men. Right and left clavicles were almost as frequently fractured, and a direct fall on the shoulder was the most frequent mechanism of injury for both genders. There was no difference between genders in the anatomical location with about three of four fractures occurring through the middle part and one of four through the acromial part of the clavicle. Ninety-five percent healed uneventfully, while non-union developed in 5% - evenly distributed between the middle part of the clavicle and the acromial part.

Enhancement of in vitro growth and resistance to gray mould of Vitis vinifera co-cultured with plant growth-promoting rhizobacteria

The potential of a plant growth-promoting rhizobacterium, Pseudomonas sp. (strain PsJN), to stimulate the growth and enhancement of the resistance of grapevine (Vitis vinifera L.) transplants to gray mould caused by Botrytis cinerea has been investigated. In vitro inoculation of grapevine plantlets induced a significant plant growth promotion which made them more hardy and vigorous when compared to non-inoculated plantlets. This ability increased upon transplanting. When grown together with B. cinerea, the causal agent of gray mould, significant differences of aggressiveness were observed between the inoculated and non-inoculated plants. The presence of bacteria was accompanied by an induction of plant resistance to the pathogen. The beneficial effect from this plant-microbe association is being postulated.

Validation of a LC method for the determination of 5-aminosalicylic acid and its metabolite in plasma and urine

The choice of a proper analytical method for the quantification of drugs and/or their metabolites in biological samples plays a significant role in the evaluation and interpretation of bioavailability, bioequivalence and pharmacokinetic data. The aim of this study was validation of a method for the identification and quantitative determination of 5-aminosalicylic acid (5-ASA) and its metabolite N-acetyl-5-aminosalicylic acid in human plasma and urine. According to previous studies on the disposition of 5-ASA (mesalazine) in a patient with inflammatory bowel diseases, we have developed a rapid, sensitive method for the determination of 5-ASA and its acetylated metabolite, N-acetyl-5-aminosalicylic acid (Ac-5-ASA). The advantage of this method is that it measures both compounds, and is more rapid, reproducible and credible than the previous studies [C. Fischer, K. Maier, U. Klotz, J. Chromatogr. Biomed. Appl. 225 (1981) 498-503; P.N. Shaw, A.L. Sivner, L. Aarons, J.B. Houston, J. Chromatogr. Biomed. Appl. 274 (1983) 393-397; B. Norlander, R. Gotthard, M. Strom, Aliment. Pharmacol. Ther. 3 (1989) 333-342; U. Klotz, G.L. Stracciari, Arzneim.-Forsch. Drug Res. II 43 (12) (1993) 1357-1359]. 5-ASA was quantitatively determined in human plasma and urine samples by liquid chromatography following prior derivatization to its acetylated metabolite (Ac-5-ASA). N-Acetyl-anthranilic acid was used as the internal standard. The detection was performed with a spectrofluorimetric detector, excitation at 311 nm, cut-off at 449 nm. The method was validated for the following parameters: linearity, recovery, sensitivity, precision, accuracy, selectivity and stability, limits of quantification and of detection. It showed good linearity (r2 > or = 0,996) in the range 0.1 ng/ml to 8 microg/ml using a Lichrospher 60 RP-select B column. The lower limit of detection was 20 ng/ml in plasma and urine. The within-run relative standard deviations (R.S.D.) were below 6.7% at all concentration levels and the between-run R.S.D. were below 25.4% at all concentration levels.

Beat-to-beat QRS amplitude variability in elite endurance athletes

Results from variance electrocardiography, displaying the wide-band, phase-locked electrical micro-variability during the depolarization phase, was analysed versus clinical data, echocardiographic structural and functional variables and myocardial scintigraphic findings in 174 elite orienteers compared with 37 age-matched elite endurance athletes and 50 age-matched, healthy medical students. PCA analysis identified a subgroup of five orienteers deviating from the rest of the study group and both control groups with regard to their QRS amplitude variability. No correlations were found between pathology by medical history or any of the echocardiographic and scintigraphic variables or by the variance electrocardiographic aberrations in any of the groups studied.

The Saccharomyces cerevisiae ubiquitin-proteasome system

Our studies of the yeast ubiquitin-proteasome pathway have uncovered a number of general principles that govern substrate selectivity and proteolysis in this complex system. Much of the work has focused on the destruction of a yeast transcription factor, MAT alpha 2. The alpha 2 protein is polyubiquitinated and rapidly degraded in alpha-haploid cells. One pathway of proteolytic targeting, which depends on two distinct endoplasmic reticulum-localized ubiquitin-conjugating enzymes, recognizes the hydrophobic face of an amphipathic helix in alpha 2. Interestingly, degradation of alpha 2 is blocked in a/alpha-diploid cells by heterodimer formation between the alpha 2 and a1 homeodomain proteins. The data suggest that degradation signals may overlap protein-protein interaction surfaces, allowing a straightforward steric mechanism for regulated degradation. Analysis of alpha 2 degradation led to the identification of both 20S and 26S proteasome subunits, and several key features of proteasome assembly and active-site formation were subsequently uncovered. Finally, it has become clear that protein (poly) ubiquitination is highly dynamic in vivo, and our studies of yeast de-ubiquitinating enzymes illustrate how such enzymes can facilitate the proteolysis of diverse substrates.

Arthroscopic lavage compared with nonoperative treatment for traumatic primary anterior shoulder dislocation: a 2-year follow-up of a prospective randomized study

A prospective randomized study was performed on 30 consecutive patients with traumatic primary anterior shoulder dislocation to compare treatment results of arthroscopic lavage with results of conventional nonoperative treatment. The patients were between 18 and 30 years of age and had no history of shoulder problems. At the 2-year follow-up, 3 (20%) of 15 patients in the lavage group had a redislocated shoulder compared with 9 (60%) of 15 patients in the nonoperative group (P = .03). Two of the patients in the lavage group compared with 6 of the patients in the control group had been operated on or were scheduled for stabilizing surgery. Functional outcome according to the Constant and Rowe shoulder scores did not reveal any significant difference (P = .07) between the groups. However, by the Rowe classification 2 of 15 patients in the lavage group had poor results versus 8 of 15 in the control group, indicating an advantage for the lavage treatment. The study showed that arthroscopic lavage reduced the risk for recurrent dislocation when compared with nonoperative treatment.

Diversity of V delta-J delta gene rearrangement in peripheral blood lymphocytes and intrathecal IgG synthesis in multiple sclerosis

The object of the study is a comparison of intrathecal IgG synthesis and gamma/delta TCR genes rearrangement in multiple sclerosis. The subgroup of 13 cases with intrathecal IgG synthesis and positive oligoclonal bands was compared with 8 cases with IgG index below 0.75 and with undetectable oligoclonal bands. TCR gene rearrangement was studied in peripheral blood lymphocytes by PCR analysis. In majority of cases of the first group the V delta-J delta junctional repertoire was restricted as evidenced by oligoclonal rearrangement. Monoclonal pattern of rearrangement was also established in some cases concerning V delta 1-J delta 1 and V delta 5-J delta 1. In all cases with one exception, demonstrating IgG index < 0.75 and with negative oligoclonal bands in CSF the oligo- or polyclonal pattern of V delta-J delta gene rearrangement was noticed. It is therefore suggested that subset T and B lymphocytes may undergo clonal expansion in MS as evidenced by restricted pattern of V delta-J delta rearrangement and intrathecal oligoclonal IgG synthesis, respectively. Oligoclonal expansion at certain B and T cells may occur due to stimulation by an antigen related to MS pathogen.

[Carbohydrate antigens CA 19-9, CA 242, CA 50 in liver diseases]

Serum concentrations of CA 19-9, CA 242, and CA 50 were determined in patients with hepatitis and liver cirrhosis without cholestasis. The study included 63 patients with chronic persistent hepatitis (group A), chronic active hepatitis (group B), and liver cirrhosis (group C). The control group (K) consisted of 82 patients with: peptic ulcer, colorectal polypi or diverticulosis of the colon. CA 19-9 level normal in the majority of patients with liver diseases, however, it was found to be increased in 4 (23%) of patients with liver cirrhosis. There was no statistically significant difference in the frequency of increased level of CA 19-9 between liver diseases and the control group. The rate of elevated serum level of CA 242 in patients with liver diseases and in control group was similar respectively 12%; 8.5%). The elevated CA 50 levels were most frequently found in patients with liver pathology (50% in liver cirrhosis and chronic active hepatitis; 36% in chronic persistent hepatitis).

CONCLUSION

The elevation of CA 50 serum level occurs very often in liver diseases, even when they are going without cholestasis. Thus, the antigen is not useful for differentiating between benign and cancer diseases of gastrointestinal tract. Antigen CA 50 is to be taken into account only after exclusion of the pathology of liver, especially cirrhosis. Other investigated antigens: CA 19-9 and CA 242 are influenced by liver diseases to a minor and neglectable extent. Antigen CA 19-9 is the marker of choice in gastrointestinal cancers.

Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats

Ipamorelin is a new and potent synthetic pentapeptide which has distinct and specific growth hormone (GH)-releasing properties. With the objective of investigating the effects on longitudinal bone growth rate (LGR), body weight (BW), and GH release, ipamorelin in different doses (0, 18, 90 and 450 microg/day) was injected s.c. three times daily for 15 days to adult female rats. After intravital tetracycline labelling on days 0, 6, and 13, LGR was determined by measuring the distance between the respective fluorescent bands in the proximal tibia metaphysis. Ipamorelin dose-dependently increased LGR from 42 microm/day in the vehicle group to 44, 50, and 52 microm/day in the treatment groups (P<0.0001). There was also a pronounced and dose-dependent effect on BW gain. The treatment did not affect total IGF-I levels, IGFBPs, or serum markers of bone formation and resorption. The number of tartrate-resistant acid phosphatase-positive multinuclear cells in the metaphysis of the tibia did not change significantly with treatment. The responsiveness of the pituitary to a provocative i.v. dose of ipamorelin or GHRH showed that the plasma GH response was marginally reduced (P<0.03) after ipamorelin, but unchanged after GHRH. The pituitary GH content was unchanged by ipamorelin treatment. Whether ipamorelin or other GH secretagogues may have a place in the treatment of children with growth retardation requires demonstration in future clinical studies.

[Surgical intraduodenal drainage of bile duct: an introductory report]

Reconstructing operations, performed on extrahepatic bile ducts, usually need protection of anastomosis by means of drainage. Classic Kehr's drainage is loaded with the risk of complications. Since 1993 the authors have been applying the alter way of drainage: an intraduodenal drainage by endoprothesis Y (DEY). Endoscopical removal of the drain was performed in 3-4 months after the operation. This way of drainage was used between III 1993--V 1997 in 23 patients. We did not observed any complications or pancreas reactions. Clinical control of patients was made after operation with ECW. In 4 cases the results of treatment were unsuccessful. In other 16 patients results of performed operations were favourable.

CONCLUSION

Proposed way of protection of bile duct's reconstruction's site using DEY decreases the number of complications connected with classic Kehr's drainage.

ESR study of plasmatic membrane of the transplantable melanoma cells in relation to their biological properties

Using the spin labelling method we studied changes in the structure and dynamics of molecular mobility in the plasmatic membrane accompanied by a spontaneous alteration of a melanotic melanoma line into an amelanotic form with a higher growth rate, changed antigenicity and immunogenicity. The calculated ratio of the low-field line (A) intensity to the central line (C) intensity of the spectrum showed statistically significant differences in the order of parameters in the plasmatic membranes of both forms of melanocytes. The significantly broader central line (deltaW0) in the spectra of labelled amelanotic melanoma cells than in the original cell line indicated changes in the membrane structure leading to a lowering of the degree of order in the phospholipid bilayer. It has been suggested that a progression of transplantable melanomas is accompanied by an increase in membrane fluidity and reduction in molecular mobility dynamics within it.

Measuring the spin polarization of a metal with a superconducting point contact

A superconducting point contact is used to determine the spin polarization at the Fermi energy of several metals. Because the process of supercurrent conversion at a superconductor-metal interface (Andreev reflection) is limited by the minority spin population near the Fermi surface, the differential conductance of the point contact can reveal the spin polarization of the metal. This technique has been applied to a variety of metals where the spin polarization ranges from 35 to 90 percent: Ni0.8Fe0.2, Ni, Co, Fe, NiMnSb, La0.7Sr0.3MnO3, and CrO2.

Enhancement of verticillium wilt resistance in tomato transplants by in vitro co-culture of seedlings with a plant growth promoting rhizobacterium (Pseudomonas sp. strain PsJN)

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.

A comparative study of fixation techniques in the open Bankart operation using either a cannulated screw or suture-anchors

The purpose of this study was to compare fixation using either Mitek suture-anchors or a cannulated screw technique, both applied extracapsularly, for an open Bankart reconstruction. Fifty-five consecutive patients with recurrent anterior dislocation of the shoulder were operated in two consecutive series. The same surgical technique was applied regardless of group, except for the reattachment method of the capsulolabral complex to the glenoid rim. Patients operated with suture-anchor fixation had better anterior stability, external rotation and functional outcome after a 24-month minimum follow-up. There were no differences between the groups regarding redislocation or subluxation rate.

Gamma/delta T cell receptor genes rearrangement in the blood and brain of multiple sclerosis patients. A preliminary study

The characterization of TCR gamma/delta gene diversity in peripheral blood lymphocytes and in cerebral white matter of MS patients was performed. In overwhelming majority of MS cases the V delta-J delta junctional repertoire was restricted as evidenced by oligoclonal rearrangements concerning V delta 1-J delta 1, V delta 2-J delta 1, V delta 3-J delta 1, V delta 5-J delta 1. The obtained results indicate, that the restricted pattern of TCR gene rearrangement may suggest oligoclonal expansion of certain clones of gamma/delta T cells that may be involved in recognition of putative autoantigen, significant in the etiopathogenesis of MS. The very striking positive correlation between monoclonal pattern of V delta-J delta rearrangement in peripheral blood and cerebral white matter of MS patients indicate that the gamma/delta T lymphocytes play significant role in MS pathogenesis.

Regulators of proliferation and apoptosis in carcinoma of the larynx

Expression of interrelated gene products regulating cell proliferation and apoptosis may be disordered in squamous cell carcinoma (SCC) of the larynx compared with normal squamous mucosa. Certain of these abnormalities, alone or in combination, may be of prognostic significance in low-stage carcinomas of the larynx. A retrospective study of archival material was made. Expression of the Bcl-2 family of apoptosis-related genes (bcl-2, bcl-X, mcl-1, and bax) and the proliferation- and apoptosis-related genes p53 and cyclin D-1 were determined in 40 low-T-stage laryngeal carcinomas and in uvular epithelium from patients without SCC. Among the antiapoptotic members of the Bcl-2 family, Bcl-X and Mcl-1 showed more intense and widespread staining than Bcl-2 itself in both normal squamous mucosa and SCC. The well-ordered expression patterns of Bcl-2-related proteins found in normal epithelium were lost in SCC, and patterns of expression varied widely among individual tumors. Also, mean expression levels for Bax and cyclin D-1 were significantly lower than in normal epithelium (P = .036 and P = .009, respectively), whereas expression of p53 was higher in tumors (P = .034). Expression of Bcl-X and Mcl-1 was greater in poorly differentiated than in well-differentiated tumors (P = .014 and P = .031, respectively). No associations were seen between marker expression patterns and clinical outcome in this group of patients. Bcl-x and Mcl-1 appear to be the most abundantly expressed antiapoptotic proteins of the Bcl-2 family in both normal squamous mucosa and SCC of the larynx. Multiple genes regulating proliferation and apoptosis are expressed abnormally in laryngeal SCC compared with normal epithelium. In particular, loss or measurable decrease in expression of the proapoptotic protein Bax in tumors may contribute to the deranged growth control of SCC. Further study is needed to evaluate the prognostic significance of particular patterns of disordered expression of proteins regulating proliferation and apoptosis in SCC of different head and neck sites.

Triiodothyronine (T3), insulin and characteristics of 5'-monodeiodinase (5'-MD) in mare's milk from parturition to 21 days post-partum

It is generally accepted that hormones and tissue growth factors are supplied from mother to neonate via mammary secretion. Among the protein hormones, insulin and prolactin are considered as the most important milk components for neonates. The significance of the thyroid hormones, namely triiodothyronine (T3) generated locally by 5'-monodeiodinase (5'-MD) in the mammary tissues, for the mammary gland itself and for suckling neonates is still under consideration. In the present study the activity of the 5'-MD and the concentrations of T3 and insulin in mare's colostrum and milk during the first 21 days of lactation were measured. Post partum, T3 increased to its highest concentration around day 4 (1.14+/-0.08 nmol/L), then progressively decreased until day 7, reaching a relatively stable concentration of 0.71+/-0.06 nmol/L (overall mean for days 7-21). The colostral insulin concentration, highest on the day of parturition (401.0 +/-24.9 microU/mL), decreased to a nadir value (25.0+/-3.4 microU/mL) on day 5, after which it tended to increase. The mare's milk showed the presence of PTU-sensitive (type I) and PTU-insensitive (type II) 5'-monodeiodinases (5'-MD). Contrary to the classical type II 5'-MD, the mare's milk isoenzyme was inhibited non-competitively by aurothioglucose. A significant relationship (r=0.962, P < 0.01 ) between T3 concentration and 5'-MD activity, from the I st to the 6th lactational day was found, which may indicate a dependence of T3 concentration on the milk 5'-MD activity. The presence of 5'-MD of type II suggests that intra-mammary T3 generation may play a paracrine role supporting lactogenesis. Estimating that 1.8 microg of colostral T3 (0.456 microg/L) is consumed daily by a suckling foal, the T3 hormone action within the intestinal tract cannot be ruled out. This is the first paper to provide evidence of T3 and insulin concentrations, and of T4-5'-monodeiodinases activity in colostrum and milk of the mare.

Telomerase activity and expression of its RNA component in cervical lesions

BACKGROUND

The authors investigated telomerase enzyme activity and expression of its RNA component (hTR) during the multistage pathogenesis of cervical carcinomas, and correlated activation with histopathologic findings and human papillomavirus (HPV) infection.

METHODS

The authors analyzed 180 cervical specimens for enzyme activity, and analyzed hTR expression in an additional 55 samples from archival carcinoma cases. Polymerase chain reaction-based assays were used to determine telomerase enzyme activity and HPV infection, whereas a radioactive in situ assay was used for hTR expression.

RESULTS

Telomerase enzyme activity was present in some samples of histologically normal epithelium (18 of 138; 13%) and low grade squamous intraepithelial lesions (LSIL) (7 of 21; 33%), and in most high grade squamous intraepithelial lesions (HSIL) (13 of 21; 62%). The relative levels of telomerase activity were low in all preinvasive specimens except for three samples of HSIL with high activity. Although 21% of the brush samples had evidence of HPV infection, there was no obvious correlation between telomerase activity and HPV status. hTR expression was low in normal squamous/glandular epithelium and LSIL lesions, in which it was limited to the basal cells. In squamous and glandular in situ and invasive carcinomas, increased and dysregulated hTR expression was observed, although heterogeneity was noted. Intense focal up-regulation of hTR expression occurred in a subset of in situ lesions.

CONCLUSIONS

Increased frequency and dysregulation of telomerase activation is correlated with increasing severity of histopathologic changes, but not with HPV infection. Whether dysregulated activity is a prognostic marker for development of invasive carcinoma remains to be determined.