The immunogenetics of narcolepsy associated with A(H1N1)pdm09 vaccination (Pandemrix) supports a potent gene-environment interaction.

The influenza A(H1N1)pdm09 vaccination campaign from 2009 to 2010 was associated with a sudden increase in the incidence of narcolepsy in several countries. Narcolepsy with cataplexy is strongly associated with the human leukocyte antigen (HLA) class II DQB1*06:02 allele, and protective associations with the DQB1*06:03 allele have been reported. Several non-HLA gene loci are also associated, such as common variants of the T-cell receptor-α (TRA), the purinergic receptor P2RY11, cathepsin H (CTSH) and TNFSF4/OX40L/CD252. In this retrospective multicenter study, we investigated if these predisposing gene loci were also involved in vaccination-associated narcolepsy. We compared HLA- along with single-nucleotide polymorphism genotypes for non-HLA regions between 42 Pandemrix-vaccinated narcolepsy cases and 1990 population-based controls. The class II gene loci associations supported previous findings. Nominal association (P-value<0.05) with TRA as well as suggestive (P-value<0.1) associations with P2RY11 and CTSH were found. These associations suggest a very strong gene-environment interaction, in which the influenza A(H1N1)pdm09 strain or Pandemrix vaccine can act as potent environmental triggers.

Alpha emitter radium-223 and survival in metastatic prostate cancer.

BACKGROUND: Radium-223 dichloride (radium-223), an alpha emitter, selectively targets bone metastases with alpha particles. We assessed the efficacy and safety of radium-223 as compared with placebo, in addition to the best standard of care, in men with castration-resistant prostate cancer and bone metastases. METHODS: In our phase 3, randomized, double-blind, placebo-controlled study, we randomly assigned 921 patients who had received, were not eligible to receive, or declined docetaxel, in a 2:1 ratio, to receive six injections of radium-223 (at a dose of 50 kBq per kilogram of body weight intravenously) or matching placebo; one injection was administered every 4 weeks. In addition, all patients received the best standard of care. The primary end point was overall survival. The main secondary efficacy end points included time to the first symptomatic skeletal event and various biochemical end points. A prespecified interim analysis, conducted when 314 deaths had occurred, assessed the effect of radium-223 versus placebo on survival. An updated analysis, when 528 deaths had occurred, was performed before crossover from placebo to radium-223. RESULTS: At the interim analysis, which involved 809 patients, radium-223, as compared with placebo, significantly improved overall survival (median, 14.0 months vs. 11.2 months; hazard ratio, 0.70; 95% confidence interval [CI], 0.55 to 0.88; two-sided P=0.002). The updated analysis involving 921 patients confirmed the radium-223 survival benefit (median, 14.9 months vs. 11.3 months; hazard ratio, 0.70; 95% CI, 0.58 to 0.83; P<0.001). Assessments of all main secondary efficacy end points also showed a benefit of radium-233 as compared with placebo. Radium-223 was associated with low myelosuppression rates and fewer adverse events. CONCLUSIONS: In this study, which was terminated for efficacy at the prespecified interim analysis, radium-223 improved overall survival. (Funded by Algeta and Bayer HealthCare Pharmaceuticals; ALSYMPCA ClinicalTrials.gov number, NCT00699751.).

Assessment of near-infrared densitometry for in situ determination of the total stratum corneum thickness on pig skin: influence of storage time.

To perform accurate tape-stripping measurements and to control for site-specific and interindividual differences the amount of stratum corneum (SC) removed by each tape and the total SC thickness must be known. The purpose of this study was to evaluate the use of near-infrared (NIR) densitometry at λ = 850 nm for in situ determination of the total SC thickness. Quantitative tape stripping was performed on pig ear skin. The amount of SC removed by each tape was measured by NIR densitometry and by microprotein assay. Derived from the linear correlation between both measurements, a conversion factor was calculated that relates the individual NIR densitometry readings to the thickness of the SC on the corresponding tape (l(SC-tape) [µm] = (abs.(850) - abs.(850)(blank))/23.9). The total SC thickness was determined based on the accumulated values of all tapes applied in quantitative tape stripping and compared to the values obtained from microscopic cross sections of biopsies. The total SC thickness was correctly determined by infrared densitometry independent of storage time and conditions (4°C up to 24 h; -21°C up to 3 months) in comparison with the standard histological evaluation.

Toxicity in patients receiving adjuvant docetaxel + hormonal treatment after radical radiotherapy for intermediate or high-risk prostate cancer: a preplanned safety report of the SPCG-13 trial.

BACKGROUND: Radical radiotherapy (RT) combined with androgen deprivation therapy is currently the standard treatment for elderly patients with localized intermediate- or high-risk prostate cancer (PC). To increase the recurrence-free and overall survival, we conducted an adjuvant, randomized trial using docetaxel (T) in PC patients (Scandinavian Prostate Cancer Group trial 13). METHODS: The inclusion criteria are the following: men >18 and ≤75 years of age, WHO/ECOG performance status 0--1, histologically proven PC within 12 months before randomization and one of the following: T2, Gleason 7 (4+3), PSA >10; T2, Gleason 8--10, any PSA; or any T3 tumors. Neoadjuvant/adjuvant hormone therapy is mandatory for all patients. The patients were randomized to receive six cycles of T (75 mgm(-2) d 1. cycle 21 d) or no docetaxel after radical RT (with a minimum tumor dose of 74 Gy). This study identifier number is NTC 006653848 (http://www.clinicaltrials.org). RESULTS: In this preplanned safety analysis of 100 patients, T treatment induced grade (G) 3 adverse events (AEs) in 15 patients (30%) and G4 AEs in 30 patients (60%), mainly due to bone marrow toxicity. Neutropenia G3--4 was observed in 72% of the patients, febrile neutropenia was found in 24% of patients, neutropenic infection in 10% of patients and G3 infection without neutropenia in 4% of patients. Nonhematological G3 AEs were rare: anorexia, diarrhea, mucositis, nausea, pain (1 patient each) and fatigue (5). Other severe serious AEs related to T were pulmonary embolism and renal failure. However, only three patients discontinued T before completing the planned six cycles. No deaths had occurred. No patients in the control arm experienced G3--4 toxicities at 12 weeks after the randomization. CONCLUSIONS: Adjuvant docetaxel chemotherapy after radiotherapy has a higher frequency of neutropenia than previous studies on patients with metastatic disease. Otherwise, the treatment was quite well tolerated.

A randomized, dose-response, multicenter phase II study of radium-223 chloride for the palliation of painful bone metastases in patients with castration-resistant prostate cancer.

PURPOSE: To investigate the dose-response relationship and pain-relieving effect of radium-223, a highly bone-targeted alpha-pharmaceutical. METHODS: One hundred patients with castration-resistant prostate cancer (CRPC) and painful bone metastases were randomized to a single intravenous dose of 5, 25, 50 or 100 k Bq/kg radium-223. The primary end-point was pain index (visual analogue scale [VAS] and analgesic use), also used to classify patients as responders or non-responders. RESULTS: A significant dose response for pain index was seen at week 2 (P = .035). At week 8 there were 40%, 63%, 56% and 71% pain responders (reduced pain and stable analgesic consumption) in the 5, 25, 50 and 100 k Bq/kg groups, respectively. On the daily VAS, at week 8, pain decreased by a mean of -30, -31, -27 and -28 mm, respectively (P = .008, P = .0005, P = .002, and P < . 0001) in these responders (post-hoc analysis). There was also a significant improvement in the brief pain inventory functional index for all dose-groups (P = .04, .01, .002 and .02, Wilcoxon signed rank test). Furthermore, a decrease in bone alkaline phosphatase in the highest dose-group was demonstrated (P = .0067). All doses were safe and well tolerated. CONCLUSION: Pain response was seen in up to 71% of the patients with a dose response observed 2 weeks after administration. The highly tolerable side-effect profile of radium-223 previously reported was confirmed.

Community-level analysis of psbA gene sequences and irgarol tolerance in marine periphyton.

This study analyzes psbA gene sequences, predicted D1 protein sequences, species relative abundance, and pollution-induced community tolerance in marine periphyton communities exposed to the antifouling compound Irgarol 1051. The mechanism of action of Irgarol is the inhibition of photosynthetic electron transport at photosystem II by binding to the D1 protein. The metagenome of the communities was used to produce clone libraries containing fragments of the psbA gene encoding the D1 protein. Community tolerance was quantified with a short-term test for the inhibition of photosynthesis. The communities were established in a continuous flow of natural seawater through microcosms with or without added Irgarol. The selection pressure from Irgarol resulted in an altered species composition and an inducted community tolerance to Irgarol. Moreover, there was a very high diversity in the psbA gene sequences in the periphyton, and the composition of psbA and D1 fragments within the communities was dramatically altered by increased Irgarol exposure. Even though tolerance to this type of compound in land plants often depends on a single amino acid substitution (Ser(264)-->Gly) in the D1 protein, this was not the case for marine periphyton species. Instead, the tolerance mechanism likely involves increased degradation of D1. When we compared sequences from low and high Irgarol exposure, differences in nonconserved amino acids were found only in the so-called PEST region of D1, which is involved in regulating its degradation. Our results suggest that environmental contamination with Irgarol has led to selection for high-turnover D1 proteins in marine periphyton communities at the west coast of Sweden.

Characterization of colon carcinoma growth pattern by computerized morphometry: definition of a complexity index.

The invasive front of carcinomas may vary in complexity from smooth to highly complex when the front splits up into small cell clusters or even single cancer cells. The degree of complexity is usually estimated visually and semiquantitatively by a pathologist, although more objective methods based on computer-assisted image analysis are available. In this study, we compared the visual estimation of the irregularity of the tumour invasion front of colon carcinomas to different quantitative image analytical techniques and defined a complexity index for the invasive margin. Sections from 29 archived colon carcinomas were stained immunohistochemically for cytokeratin 8. Images of the tumour invasion front were read into a computer and thresholded so that the tumour tissue became black and the background white or so that the tumour front was outlined by a single pixel line. The invasive front was visually classified into four degrees of irregularity by a pathologist. The complexity of the front was then assessed using four different image analysis techniques, i.e. the estimation of fractal dimension, tumour front length, number of tumour cell clusters and lacunarity. Fractal dimension and tumour cell clusters together gave the best correlation to visual grading using a discriminant analysis. A cluster analysis and a tree diagram analysis were then performed and were found to be superior to visual estimation. The clusters represent different degrees of complexity and the result of the tree diagram analysis can be used to assign complexity indices to colon tumours. The fractal dimension separated tumours up to a certain level (1.5-1.6) of complexity. When the tumour front split up into small cell clusters, the counting of tumour cell clusters separated the cells over and above the fractal dimension. This new technique can be used to objectively and quantitatively describe the complexity of the invasive front of tumours.

Increased uptake of non-pathogenic E. coli via the follicle-associated epithelium in longstanding ileal Crohn's disease.

In Crohn's disease (CD), inflammation is driven by luminal commensal micro-organisms; however, mechanisms of early phases of inflammation need further clarification. The earliest observable lesions of recurrent CD are microscopic erosions at the specialized follicle-associated epithelium (FAE), which lines the Peyer's patches. Therefore, our aim was to investigate the mucosal barrier to non-pathogenic bacteria in FAE of CD. The FAE of macroscopically normal ileum from patients with longstanding CD, ulcerative colitis, and controls was studied in Ussing chambers regarding electrophysiology and permeability to 51Cr-EDTA, horseradish peroxidase, and non-pathogenic E. coli strains. Transepithelial passage routes and uptake into dendritic cells were studied by confocal and electron microscopy. FAE of CD showed increased numbers of adherent bacteria, after E. coli exposure in Ussing chambers, as well as spontaneously in non-exposed archival surgical tissues. Further, we found increased uptake of fluorescent E. coli K-12 and HB101 across FAE of CD, but not in ulcerative colitis. Microscopy demonstrated intercellular and transcellular uptake of E. coli in CD, but only transcellular in controls. FAE exposed to E. coli demonstrated changes in conductance and 51Cr-EDTA permeability, suggesting that bacteria affected the paracellular pathway in CD mucosa. Following bacterial uptake, CD mucosa also demonstrated an increased percentage of E. coli co-localizing with dendritic cells, and augmented tissue release of TNF-alpha. Our data present novel insights into the pathophysiology of CD by demonstrating a previously unrecognized defect of FAE barrier to bacteria in ileal CD, leading to increased load of commensal bacteria to the inductive sites of mucosal immunity.

Duodenal intraepithelial lymphocyte-count revisited.

BACKGROUND: The number of intraepithelial lymphocytes in the duodenum was determined 30 years ago, the suggested normal upper limit being 40 lymphocytes per 100 epithelial cells. METHODS: Duodenal mucosa was analysed from 18 healthy individuals and 56 consecutive patients biopsied because of epigastralgia (17 cases), diarrhoea (10 cases), oesophagitis (10 cases), iron-deficiency (9 cases) and B12-deficiency (10 cases) showing normal histology, along with 10 cases of active coeliac disease. The biopsies were fixed in 4% formalin overnight and embedded in paraffin. Three micrometre thick sections were stained with haematoxylin and eosin and CD3. At least 300 epithelial cells were counted, the number of intraepithelial lymphocytes was given as the mean/100 epithelial cells. Extensive statistical analyses were performed. RESULTS: In the healthy individuals the mean number (s) of intraepithelial lymphocytes/100 epithelial cells was 10.8 (2.6) and 13.2 (3.8) in H&E and CD3 stained sections, respectively. The upper limit of the confidence interval for CD3 staining was 29. There was no significant difference between normal individuals and the clinical groups, with the exception of coeliac disease. CONCLUSION: Two-step analysis of intraepithelial lymphocyte-determination is suggested: (a) semi-quantitative estimate on H&E-stained sections (normal ratio of 1:5 between lymphocytes and enterocytes; upper normal limit 20 lymphocytes) and (b) CD3-staining and counting if intraepithelial lymphocytosis is suspected. The upper normal range of intraepithelial lymphocytes is set at 25 CD3+ lymphocytes/100 epithelial cells. Values between 25 and 29 are regarded as 'borderline' and 30 or more represent pathologic intraepithelial lymphocytosis in the duodenum.

Structure, organization and expression of the genes encoding mitochondrial cytochrome c(1) and the Rieske iron-sulfur protein in Chlamydomonas reinhardtii.

The sequence and organization of the Chlamydomonas reinhardtii genes encoding cytochrome c(1) ( Cyc1) and the Rieske-type iron-sulfur protein ( Isp), two key nucleus-encoded subunits of the mitochondrial cytochrome bc(1) complex, are presented. Southern hybridization analysis indicates that both Cyc1 and Isp are present as single-copy genes in C. reinhardtii. The Cyc1 gene spans 6404 bp and contains six introns, ranging from 178 to 1134 bp in size. The Isp gene spans 1238 bp and contains four smaller introns, ranging in length from 83 to 167 bp. In both genes, the intron/exon junctions follow the GT/AG rule. Internal conserved sequences were identified in only some of the introns in the Cyc1 gene. The levels of expression of Isp and Cyc1 genes are comparable in wild-type C. reinhardtii cells and in a mutant strain carrying a deletion in the mitochondrial gene for cytochrome b (dum-1). Nevertheless, no accumulation of the nucleus-encoded cytochrome c(1) or of core proteins I and II was observed in the membranes of the respiratory mutant. These data show that, in the green alga C. reinhardtii, the subunits of the cytochrome bc(1) complex fail to assemble properly in the absence of cytochrome b.

Early increase and later decrease in VIP and substance P nerve fiber densities following abdominal radiotherapy: a study on the human colon.

PURPOSE: The neuropeptides substance P (SP) and vasoactive intestinal peptide (VIP) mediate physiologic activities in the intestine, not least in relation to motility and inflammatory processes. Neuropeptides are up-regulated and play particular importance during tissue stress. This paper aims to quantify mucosal and smooth muscle SP, VIP and total innervation in human colon in short- and long-term perspectives after abdominal irradiation. MATERIALS AND METHODS: Colon specimens from 23 irradiated or non-irradiated patients were investigated with immunohistochemistry and computerized image analysis. Plasma levels of SP and VIP in 15 additional patients receiving radiotherapy were analyzed. RESULTS: At 4-7 days after irradiation (5 x 5 Gy), the overall innervation, and also VIP and SP nerve fiber densities, were increased in both mucosa and circular muscle layer. In contrast, 5-6 weeks as well as several years after irradiation, the VIP and SP nerve fiber densities were decreased. No peptide changes were revealed in plasma. CONCLUSIONS: The degree of VIP and SP intestinal innervation was increased after radiotherapy in the short-term perspective but it decreased in the long-term. In the short-term, SP may have pro-inflammatory and VIP anti-inflammatory effects and the peptides may have trophic effects and be related to the occurrence of motor changes. It cannot be excluded that the decrease in VIP and SP neuronal supply seen in the long-term may contribute to intestinal malfunction.

Increased liver echogenicity at ultrasound examination reflects degree of steatosis but not of fibrosis in asymptomatic patients with mild/moderate abnormalities of liver transaminases.

AIMS: To investigate whether hyperechogenicity of liver can reliably be interpreted as liver steatosis and if any concomitant or isolated fibrosis can be disclosed. PATIENTS AND METHODS: A series of 165 patients with no signs or symptoms of liver disease referred because of slightly to moderately raised aminotransferases (alanine aminotransferase and/or aspartate aminotransferase 0.7-5.0 microkat/l) for more than 6 months were prospectively investigated with a comprehensive laboratory profile, ultrasound examination of liver and percutaneous liver biopsy Fibrosis was assessed quantitatively and according to Metavir. Steatosis was graded as none, mild, moderate or severe. RESULTS: Of 98 (59.4%) patients with raised echogenicity, 85 (86.7%) had liver steatosis of at least moderate degree, 9 patients with same degree of steatosis had normal echogenicity and 13 patients with no or only mild steatosis had a hyperechogenic liver (sensitivity 0.90, specificity 0.82, positive predictive value 0.87, negative predictive value 0.87). About the same relations were found regardless of body mass index and degree of fibrosis. With increased echogenicity together with high attenuation (n = 591 and reduced portal vessel wall distinction (n = 79), positive predictive value increased to 0.93 and 0.94, respectively. Quantitatively assessed fibrosis (mean +/- SD) was 3.2 +/- 4.6% of biopsy area with normal and 2.3 +/- 1.8% with raised echogenicity (ns). Echogenicity was normal in 5 out of 9 patients with septal fibrosis and in 4 out of 6 patients with cirrhosis. Any structural, non-homogenous findings at ultrasound were not associated with architectural fibrotic changes and none had nodular contours of liver surface. CONCLUSIONS: Assessment of liver echogenicity is of value for detection or exclusion of moderate to pronounced fatty infiltration (correct classification 86.6%) but cannot be relied upon in diagnosing fibrosis, not even cirrhosis in asymptomatic patients with mild to moderately elevated liver transaminases.

Regression of Peyer's patches in G alpha i2 deficient mice prior to colitis is associated with reduced expression of Bcl-2 and increased apoptosis.

BACKGROUND: G protein deficient (G alpha i2-/-) mice spontaneously develop an inflammatory bowel disease (IBD) closely resembling ulcerative colitis. Previous studies have demonstrated that gut T cells are hyperreactive to the endogenous microflora in most IBD models. AIMS: The aim of this study was to analyse Peyer's patches (PP), the inductive sites for gut mucosal immune responses. SUBJECTS AND METHODS: G alpha i2-/- mice, an animal model for IBD, were analysed using immunological methods with regard to phenotype and function. RESULTS: We found significantly decreased numbers of PP in G alpha i2-/- mice. Even before the onset of colitis, G alpha i2 deficient animals exhibited diminished size of PP, as judged by histology. This involution of PP was associated with strongly increased levels of apoptotic lymphocytes, associated with decreased levels of antiapoptotic intracellular protein Bcl-2. PP T lymphocytes showed highly elevated production of interferon gamma in response to the enteric flora compared with PP T cells from wild-type mice, which produced predominantly interleukin 10. CONCLUSIONS: Thus even before the onset of colitis, the PP in G alpha i2 deficient mice is a Th1 dominated milieu associated with downregulated levels of Bcl-2, resulting in increased apoptosis of lymphocytes leading to regression of PP. We speculate that this Th1 dominated microenvironment in the inductive site for mucosal immune responses contributes to the development of colitis in G alpha i2 deficient mice.

Prevalence of subtypes of intestinal metaplasia in the general population and in patients with autoimmune chronic atrophic gastritis.

BACKGROUND: Gastric intestinal metaplasia (IM) is seen mostly in association with chronic gastritis, induced either by Helicobacter pylori infection or autoimmune mechanisms. IM can be categorized into three subtypes, where type III is associated with gastric carcinoma of intestinal type. METHODS: Gastric biopsies from 475 subjects randomly selected from the general population and from 27 patients with autoimmune gastritis associated with pernicious anaemia were used. The criteria of Filipe & Jass were applied using different histochemical techniques in combination with haematoxylin and eosin stained material. RESULTS: Twenty-three percent (109/475) of the subjects from the general population and 88% (24/27) in the group with autoimmune gastritis had IM. Type III IM occurred in 4% in both populations. Type III IM was located in the antrum in 90% in the general population. In the group with autoimmune gastritis, only one patient had type III IM, which was located in the corpus. CONCLUSIONS: This study reveals for the first time the prevalence and distribution of subtypes of IM in a general population from the Western world. The comparatively high prevalence of type III IM in the general population (4%) indicates that its role as a precursor of gastric carcinoma may have been overemphasized. A similar prevalence of type III IM in patients with autoimmune gastritis may be considered low and suggests that mechanisms for gastric carcinogenesis other than the atrophy-metaplasia-dysplasia sequence could also operate in this condition.

Augmented increase in tight junction permeability by luminal stimuli in the non-inflamed ileum of Crohn's disease.

BACKGROUND: Crohn's disease is associated with deranged intestinal permeability in vivo, suggesting dysfunction of tight junctions. The luminal contents are important for development of neoinflammation following resection. Regulation of tight junctions by luminal factors has not previously been studied in Crohn's disease. AIMS: The aim of the study was to investigate the effects of a luminal stimulus, known to affect tight junctions, on the distal ileum in patients with Crohn's disease. PATIENTS: Surgical specimens from the distal ileum of patients with Crohn's disease (n=12) were studied, and ileal specimens from colon cancer patients (n=13) served as controls. METHODS: Mucosal permeability to 51Cr-EDTA and electrical resistance were studied in Ussing chambers during luminal exposure to sodium caprate (a constituent of milk fat, affecting tight junctions) or to buffer only. The mechanisms involved were studied by mucosal ATP levels, and by electron and confocal microscopy. RESULTS: Baseline permeability was the same in non-inflamed ileum of Crohn's disease and controls. Sodium caprate induced a rapid increase in paracellular permeability--that is, increased permeation of 51Cr-EDTA and decreased electrical resistance--which was more pronounced in non-inflamed ileum of Crohn's disease, and electron microscopy showed dilatations within the tight junctions. Moreover, sodium caprate induced disassembly of perijunctional filamentous actin was more pronounced in Crohn's disease mucosa. Mucosal permeability changes were accompanied by mitochondrial swelling and a fall in epithelial ATP content, suggesting uncoupling of oxidative phosphorylation. CONCLUSIONS: The tight junctions in the non-inflamed distal ileum of Crohn's disease were more reactive to luminal stimuli, possibly mediated via disturbed cytoskeletal contractility. This could contribute to the development of mucosal neoinflammation in Crohn's disease.

External radiation of the parotid glands significantly reduces drooling in patients with motor neurone disease with bulbar paresis.

The parotid glands and part of the submandibular glands were irradiated in 18 amyotrophic lateral sclerosis patients with very advanced disease and severe drooling problems. In a prospective study, a single dosage of 7.0-7.5 Gy was administered bilateral to the larger part of the parotid glands and the posterior parts of the submandibular glands. Salivary secretion rate was assayed before and after radiotherapy. Sixteen out of eighteen patients reported satisfactory to good reduction in drooling lasting up to 4-6 months, 1/18 developed xerostomia and needed saliva substitutes, and 1/18 reported no effect. Caregivers reported positive effect in all patients. The procedure was well tolerated with few side effects. Low dosage external radiotherapy of the salivary glands is effective in reducing drooling satisfactorily in ALS patients, especially in well-hydrated patients.

Carrageenan-induced subacromial bursitis caused changes in the rat's rotator cuff.

This study was designed to investigate the histologic expression of the rat's supra- and infraspinatus tendons in carrageenan-induced subacromial bursitis. Thirty-two rats received subacromial injections with carrageenan (n = 28) or saline (n = 4). The tendons were analysed microscopically after staining with hematoxyline eosin, Van Giesons hematoxyline and immunofluorescent staining of fibronectin and fibrinogen. In the controls (saline x 10) and group A (carrageenan x 5) there were no changes in the tendons. In group B (carrageenan x 10) 3/8 rats showed macrophages between the collagen fibres and an increased staining of fibronectin. In group C (double dosis carrageenan) all rats had signs of fibrocartilaginous metaplasia in the supraspinatus tendon. In eight of these specimens even bony metaplasia was seen. The infraspinatus tendon showed fibrosis but no fibrocartilaginous metaplasia. The results showed that iatrogenic bursitis after carrageenan subacromial injections was associated with marked changes of the supraspinatus tendon.

Cycloheximide resistance conferred by novel mutations in ribosomal protein L41 of Chlamydomonas reinhardtii.

Although most eukaryotic cells are sensitive to the 80S ribosome inhibitor cycloheximide (CYH), naturally occurring CYH resistance is widespread amongst yeast species. The primary determinant of resistance appears to be a single residue within ribosomal protein L41; resistance is acquired by the substitution of a conserved proline (P56) by a glutamate residue. We have isolated the L41 gene (RPL41) from the green alga Chlamydomonas reinhardtii, and investigated the molecular basis of CYH resistance in various mutant strains. In both the wild-type strain and the mutant act-1, a proline is found at the key position in L41. However, analysis of six independently isolated act-2 mutants reveals that all have point mutations that replace the proline with either leucine or serine. Of the two changes, the leucine mutation confers significantly higher levels of CYH resistance. This work identifies the ACT-2 locus as RPL41 and provides a possible dominant marker for nuclear transformation of C. reinhardtii.