Fine mapping of a tumour suppressor candidate gene region in 1p36.2-3, commonly deleted in neuroblastomas and germ cell tumours

BACKGROUND: A common genetic feature of neuroblastomas, which is also an important prognostic factor, is deletion of chromosome region 1p. The deletion of 1p often involves a deletion of varying size, with a consensus region within the most distal bands 1p36.2-3. The neuroblastoma SRO (shortest region of overlap of (deletions) presented earlier by our group was defined distally by the cluster of loci D1S80/ D1Z2/CDC2L1 and proximally by loci D1S244, i.e., approximately 25 cM. The 1p deletions are, however, not restricted to neuroblastoma tumours. In fact, a large spectrum of tumour types display deletions to varying degrees of 1p. PROCEDURE: We have exploited the possibility of using deletions of other tumour types, preferentially that of germ cell tumours, and combining the deletions with that of the neuroblastoma SRO. Also in germ cell tumours, distal 1p-deletions have been shown to have prognostic significance. RESULTS: We found in our germ cell tumours a SRO ranging from D1S508 to D1S200. Interestingly, this region only partially overlapped (approximately 5 cm) with our neuroblastoma SRO in region D1S508 to D1S244. We have thus focused on analysing this smaller region in the search for genes involved in the genesis of different cancers. We have performed radiation hybrid mapping of a large number of markers, STSs, ESTs, and others known to reside in 1p. We have also initiated the development of a BAC contig of the region. FISH, and fibre-FISH mapping of BACs were also performed. CONCLUSIONS: The data presented here constitute an ongoing work with the aim of identifying and cloning gene(s) important for development of germ cell tumours, neuroblastomas, and possibly other tumours.     

MECP2 mutation screening in Swedish classical Rett syndrome females

Rett syndrome (RS) is a neurodevelopmental disorder almost exclusively affecting females. We have studied the mutation spectrum of the responsible gene MECP2, encoding methyl-CpG-binding protein 2 (MeCP2), in 16 sporadic classical RS females from Sweden. In 13 of 16 patients (81%) we detected nonsense or missense mutations in the coding parts of MECP2. This mutation rate is in agreement with other reports (65-80%). In all, 12 different mutations and one polymorphism were found; three of the mutations have not been reported previously. The missense mutations were restricted to highly conserved regions of the gene. None of the mutations was detected in parents; thus, they had probably arisen de novo. In contrast, two normal variants, one intron deletion and one silent mutation, were seen singly only in two patients' mothers; neither has been reported previously. One patient showed two different mutations closely located, i.e. 802C > T (R268W) together with 808C > T (R270X). Another patient had a mutation in the stop codon 1459T > C (X487R), leading to a gene product prolonged with 27 amino acids. In conclusion, our results indicate that the majority of Swedish RS patients (81%) have mutations in MECP2 that are sporadic cases with de novo mutations. Moreover, both missense and nonsense mutations occur, but in different parts of the gene, probably reflecting the function of the domains in MeCP2. This study has improved our ability to offer these families an early confirmation of Rett diagnoses.     

Multiple mitochondrial DNA deletions in hereditary inclusion body myopathy

We have recently described an autosomal dominant hereditary inclusion body myopathy (h-IBM). Clinically it is is characterized by congenital joint contractures and slowly progressive, proximal muscle weakness and ophthalmoplegia. There is deterioration of muscle function between 30 and 50 years of age. While young patients show minor pathological changes in muscle, the middle-aged and old patients show rimmed vacuoles and inclusions of filaments measuring 15–18 nm in diameter. Except for the absence of significant inflammation the histopathology is similar to that found in sporadic inclusion body myositis (s-IBM). In s-IBM mitochondrial alterations including cytochrome c oxidase (COX) -deficient muscle fibers are common. These are due to multiple mitochondrial DNA (mtDNA) deletions. In this study we investigated the occurrence of mitochondrial alterations in autosomal dominant h-IBM. Young affected individuals showed no mitochondrial changes but three patients aged 38, 51 and 59 years, respectively, showed ragged red fibers and COX-deficient muscle fibers. Polymerase chain reaction analysis showed multiple mtDNA deletions. By in situ hybridization clonal expansions of mtDNA with deletions were demonstrated in COX-deficient muscle fibers. Most of the analyzed deletion breakpoints showed nucleotide repeats flanking the deletions. The results show that COX-deficient muscle fibers and somatic mtDNA deletions are present in this family with h-IBM. The same factors may be involved in the development of mtDNA deletions in s-IBM and this family with h-IBM. Received: 13 July 1999 / Revised: 6 October 1999 · Accepted: 12 October 1999     

Relatives’ perspective on the quality of geriatric care and rehabilitation – development and testing of a questionnaire

We perceived a need for relatives’ evaluation of geriatric care and rehabilitation during the care period as well as the first few weeks after discharge. The aim of this study was therefore to develop and test a questionnaire for use in telephone interviews with relatives of patients discharged from geriatric wards to measure their perceptions of the quality of care. The instrument development process comprised a literature review, focus group interviews, construction of items, test of content validity, a pilot study and finally the main data collection to test the construct validity and reliability. A Likert‐type questionnaire was used containing 26 items with five response alternatives; totally disagree, partly disagree, doubtful, partly agree and totally agree. The main data collection comprised 238 telephone interviews. The factor analysis revealed four factors with an eigenvalue >1.0. Cronbach’s alpha coefficient was 0.89, which indicates high reliability. The duration of the telephone interview was approximately 10–20 minutes. The relatives appreciated the opportunity to evaluate the care, and a majority stated that they preferred a telephone interview to answering in writing. The questionnaire is considered reliable, valid and useful for identifying areas in need of quality improvement interventions.     

Plasma neuropeptide Y-like immunoreactivity and catecholamines during various degrees of sympathetic activation in man

Neuropeptide Y-like immunoreactivity (NPY-LI) and catecholamine concentrations in plasma were analysed during and after 60 min of physical exercise at a work load corresponding to 70% of individual maximal oxygen uptake in nine healthy men of average physical fitness. Systemic plasma NPY-LI increased progressively from 18 +/- 3 to 81 +/- 19 pmol X 1(-1) in parallel with a 10-fold increase in noradrenaline (NA) concentration. The increase in plasma NPY-LI during exercise and the decrease after completion of exercise were much slower than the corresponding changes in NA concentration. This difference is probably related to a slower diffusion of NPY into systemic circulation after release, as well as to a longer half-life of NPY than of NA in plasma. Reversed phase HPLC and sephadex G-50 gel-filtration chromatography revealed that the main component of NPY-LI in plasma during exercise eluted in a similar position as synthetic human NPY. During exercise plasma NPY-LI correlated well with the plasma concentration of NA (r = 0.80), but not with that of adrenaline (ADR), suggesting a neuronal origin of NPY. The self-ratings of perceived exertion (RPE) were well correlated with the plasma concentrations of both NPY-LI and NA. No clear-cut veno-arterial concentration difference was observed for NPY-LI. Isometric handgrip and orthostatic test doubled plasma NA concentrations but did not cause any increase in plasma NPY-LI. No change in plasma tachykinin-like immunoreactivity was detected during exercise. The present data suggest that NPY is released together with NA during strong, but probably not during mild, sympathetic activation under physiological conditions in man.     

Skeletal muscle changes following myelotomy in paraplegic patients

Pourpre's dorsal T-shaped myelotomy was performed on three paraplegic patients in which medical and electro-physiological procedures proved to be ineffective concerning muscle spasms. The myelotomy led to the elimination of spasms and of muscle hypertonicity in the lower limbs. Biopsies of the rectus femoris muscles were performed bilaterally one year before and two months following myelotomy. The first biopsy revealed fascicular atrophy, with type I fibre preferential atrophy, which is usually found in paraplegic patients. After myelotomy some histological differences were seen: reduction of type II fibre diameter and the presence of target-targetoid fibres and of atrophic dark fibres. There was a difference of fibre pattern type in hypertonic spastic muscles compared to that seen in spasm relieved by myelotomy. The morphological changes seen after myelotomy are interpreted as denervation changes because of the surgical lesion by the myelotomy on the anterior horn cells.     

Sclerosing injections to treat midportion Achilles tendinosis: a randomised controlled study evaluating two different concentrations of Polidocanol

Two to three ultrasound (US) and colour Doppler (CD)-guided injections of the sclerosing substance Polidocanol (5 mg/ml) have been demonstrated to give good clinical results in patients with chronic midportion Achilles tendinopathy. This study aimed to investigate if a higher concentration of Polidocanol (10 mg/ml) would lead to a less number of treatments, and lower volumes, needed for good clinical results. Fifty-two consecutive Achilles tendons (48 patients, mean age 49.6 years) with chronic painful midportion Achilles tendinopathy, were randomised to treatment with Polidocanol 5 mg/ml (group A) or 10 mg/ml (group B). The patients and treating physician were blinded to the concentration of Polidocanol injected. All patients had structural tendon changes and neovascularisation in the Achilles midportion. Treatment was US + CD-guided injections targeting the region with neovascularisation (outside ventral tendon). A maximum of three treatments (6-8 weeks in between) were given before evaluation. Patients not satisfied after three treatments were given additional treatment with Polidocanol 10 mg/ml, up to five treatments. For evaluation, the patients recorded the severity of Achilles tendon pain during activity on a visual analogue scale (VAS), before and after treatment. Patient satisfaction with treatment was also assessed. At follow-up (mean 14 months) after three treatments, 18/26 patients in group A and 19/26 patients in group B were satisfied with the treatment and had a significantly reduced level of tendon pain (P < 0.05). After completion of the study, additional treatments with Polidocanol 10 mg/ml in the not satisfied patients resulted in 26/26 satisfied patients in both groups A and B. In summary, we found no significant differences in the number of satisfied patients, number of injections or volumes given, between patients treated with 5 or 10 mg/ml Polidocanol.     

Identification of 12 novel mutations in the SLC3A1 gene in Swedish cystinuria patients

Cystinuria is an autosomal recessive disorder that affects luminal transport of cystine and dibasic amino acids in the kidneys and the small intestine. Three subtypes of cystinuria can be defined biochemically, and the classical form (type I) has been associated with mutations in the amino acid transporter gene SLC3A1. The mutations detected in SLC3A1 tend to be population specific and have not been previously investigated in Sweden. We have screened the entire coding sequence and the intron/exon boundaries of the SLC3A1 gene in 53 cystinuria patients by means of single strand conformation polymorphism (SSCP) and DNA sequencing. We identified 12 novel mutations (a 2 bp deletion, one splice site mutation, and 10 missense mutations) and detected another three mutations that were previously reported. Five polymorphisms were also identified, four of which were formerly described. The most frequent mutation in this study was the previously reported M467T and it was also detected in the normal population with an allelic frequency of 0.5%. Thirty‐seven patients were homozygous for mutations in the SLC3A1 gene and another seven were heterozygous which implies that other genes may be involved in cystinuria. Future investigation of the non‐type I cystinuria gene SLC7A9 may complement our results but recent studies also suggest the presence of other potential disease genes. Hum Mutat 18:516–525, 2001. © 2001 Wiley‐Liss, Inc.     

Prevalence of apical periodontitis, crowned teeth and teeth with posts in a Swedish population

Abstract A longitudinal radiological study was carried out of 200 consecutive patients in a Swedish population. The aims of the investigation were to study the prevalences of crowned teeth, pontics and posts on two occasions with an interval of 5–7 years and, furthermore, to study apical periodontitis in connection with teeth with crowns and posts to see if such treatments affected this prevalence. 417 (mean 2.1) teeth were crowned at the first examination and 529 (mean 2.6) at the second. For pontics, the corresponding figures were 93 (mean 0.5) and 141 (mean 0.7). Crowns and pontics were more common in the upper jaw. 59.4% of the endodontically treated teeth had posts at the first examination and 64.4% at the second. 34.5% of the 255 teeth with apical periodontitis found at the first examination and 41.0% of the 268 at the second were in connection with posts. It was concluded that both crowns and pontics were common treatment procedures in the studied population. Crown therapy did not seem to impair the apical status while teeth with posts more often had apical periodontitis than other teeth and, furthermore, teeth with screw posts were lost more frequently than other teeth.