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Biomedical subjects

K Borg

Publications and source records attributed to K Borg.

At least 37 records · Page 2Linked to original sources

A missense mutation in the desmin rod domain is associated with autosomal dominant distal myopathy, and exerts a dominant negative effect on filament formation.

In some myopathies of distal onset, the intermediate filament desmin is abnormally accumulated in skeletal and cardiac muscle. We report the first point mutation in desmin cosegregating with an autosomal dominant form of desmin-related myopathy. The L345P desmin missense mutation occurs in a large, six generation Ashkenazi Jewish family. The mutation is located in an evolutionarily highly conserved position of the desmin coiled-coil rod domain important for dimer formation. L345P desmin is incapable of forming filamentous networks in transfected HeLa and SW13 cells. We conclude that the L345P desmin missense mutation causes myopathy by interfering in a dominant-negative manner with the dimerization-polymerization process of intermediate filament assembly.

Amino Acid Sequence↗

Analysis of sensory function in Charcot-Marie-Tooth disease.

Ten patients each with Charcot-Marie-Tooth disease type 1 (CMT1), demyelinating form, and CMT2, axonal form, were subjected to analysis of sensory function including sensory screening and quantitative determination of thermal, thermal pain and vibratory thresholds in hands and feet. The threshold values were compared with data from age- and sex-matched control groups. All patients had a symmetrical sensory dysfunction, which was most prominent in the lower extremities. Temperature was the modality most often affected on screening and on quantitative determination of thresholds in both CMT1 and CMT2 patients. Mean thermal thresholds were significantly increased in both hands and feet in CMT1 as well as in CMT2 patients when compared with controls. There was no statistically significant difference between thermal thresholds in the CMT1 and CMT2 patients. Mean thermal pain thresholds were significantly increased in the feet of the CMT2 patients when compared with the controls and they were significantly higher in the hands of the CMT2 than in the CMT1 patients. Vibratory thresholds (VT) were abnormal in all CMT1 patients and in a majority of the CMT2 patients. Mean VT was significantly increased in hands and feet of both CMT1 and CMT2 patients when compared with the controls and the mean VT was significantly higher in the feet of the CMT1 than in the CMT2 patients. The difference with an increased heat pain threshold in the CMT2 patients and an increased VT in the CMT1 patients is suggested to be due to demyelination in CMT1 leading to affection of sensory function mediated by myelinated nerve fibres and to axonal disturbance in CMT2 with affection of sensory function mediated by small diameter myelinated and unmyelinated C-fibres.

Adult↗

Effects of high resistance training in patients with myotonic dystrophy.

Nine ambulatory subjects with myotonic dystrophy participated in a supervised 12-week progressive high-resistance training program. Knee extensor muscles were trained 3 times a week with free weights, 3 x 10 repetitions at 80% of 1RM. One leg was randomly chosen for training and the other served as control. Six patients completed the training program. In the trained leg, 1RM increased from 16.4 +/- 3.4 kg to 21.8 +/- 2.6 kg (p = 0.0002). There was no difference between pre- and post-training concentric or eccentric isokinetic values at 30 degrees/second in either leg. Muscle biopsy from m. vastus lateralis in the trained leg revealed no systematic difference in the degree of histopathological abnormalities before and after training. After training, there was a tendency toward increase in cross-sectional area of type I muscle fibres. However, the number of subjects was too small to draw conclusions regarding the effects of training on the histopathological changes. Magnetic resonance imaging revealed no difference in the m. quadriceps area after training. In conclusion, patients with myotonic dystrophy improved their muscle strength without any observed negative side effects after a 12-week high-resistance training program.

Adult↗

The effect of intermittent injections of CCK-8S and the CCK-A receptor antagonist devazepide on cell proliferation in exocrine rat pancreas.

CONCLUSION: Intermittent injections of sulfated cholecystokinin-8 (CCK-8S) or devazepide caused long-lasting effects on cell proliferation in exocrine pancreas in contrast to continuous infusion. The acinar cells responded to both treatments with changes in the labeling index (LI) during the whole study period. When studying the influence of stimulation and inhibition of the CCK-A receptor on cell proliferation in the exocrine pancreas, not only are the drugs and doses of importance but also the mode of administration. BACKGROUND: Continuous infusion of CCK-8S or the CCK-A receptor antagonist devazepide induces transient changes in acinar cell proliferation in rat pancreas. The aim of the present experiments was to study whether intermittent administration of CCK-8S or devazepide prevents receptor desensitization and thereby affects exocrine pancreatic cell proliferation persistently. METHODS: Male Sprague-Dawley rats were injected subcutaneously twice daily with CCK-8S (6 micrograms), devazepide (240 micrograms) or bovine serum albumin (BSA). The rats were sacrificed after 18 and 36 h and 3 and 7 d. One hour before sacrifice, the rats were injected intraperitoneally with 1 mCi/kg of tritiated thymidine. The pancreatic weight and the contents of water, protein, and DNA were determined. The LI (number of labeled cells/100 cells) of exocrine pancreatic cells was determined microscopically after autoradiography. RESULTS: The concentration of plasma CCK was slightly increased by devazepide, but the increase was more pronounced by CCK-8S. The pancreatic wet weight was transiently increased 18 h after the start of CCK-8S injections (+14%), whereas devazepide caused a reduction after 7 d (-22%). The protein content was uninfluenced and the DNA content was decreased at 36 h with either treatment. CCK-8S increased the LI in acinar and centroacinar cells throughout the study period, but the ductal cell LI was increased only after 18 and 36 h. Injection of devazepide was followed by decreased LI of acinar cells throughout the study period. Also, the centroacinar and ductal cell LI decreased initially but returned to control values after 7 d.

Animals↗

Welander hereditary distal myopathy, a molecular genetic comparison to hereditary myopathies with inclusion bodies.

Welander distal myopathy (WDM) is an autosomal dominant disorder with late onset predominantly affecting distal extensor muscles of the hands and the feet. The disorder is considered as the most common of the distal myopathies but is almost only seen in Sweden and some parts of Finland. The finding of rimmed vacuoles in muscle biopsies from patients with moderate and severe symptoms constitutes one similarity with hereditary inclusion body myopathy (HIBM) sparing the quadriceps as described by Argov and Yarom [Argov Z, Yarom R. J Neurol Sci 1984;64:33-43]. The question has been raised whether some of the different forms of distal myopathy might be allelic. In previous reports the gene defects for HIBM and autosomal recessive hereditary distal myopathy with rimmed vacuoles (DMRV) have been mapped to chromosome 9pl-q1. The Finnish tibial muscular dystrophy (TMD) that displays similar histopathological findings has recently been linked to chromosome 2q. We have investigated the regions of interest with dispersed microsatellite markers in four well-described pedigrees, and this study now excludes the regions on chromosome 9pl-q1 and 2q from linkage to WDM both by haplotype analysis and linkage analysis with the MLINK program. WDM, showing morphological similarities with HIBM, is clearly separated from the disorders mapped to chromosomes 9 and 2 on clinical and genetical grounds.

Adult↗

Welander distal myopathy--an overview.

Welander distal myopathy has an autosomal dominant inheritance and a late onset. The onset of symptoms is in the hands and gradually distal muscles of the lower extremities are involved. The most-affected muscles are the long extensors of the hands and feet. CK-values are normal or slightly elevated. There is never any cardiac involvement in Welander distal myopathy. Neurophysiological findings are of both myopathic and neuropathic character. Histopathological findings in muscle biopsies are mainly of myopathic type and include rimmed vacuoles which correspond to autophagic vacuoles on the ultrastructural level. Tubulo-filamentous inclusions with a diameter of 16-21 nm, i.e. of the same type as found in patients with Inclusion Body Myositis, are found in the sarcoplasm and in myofibre nuclei. A neurogenic component in Welander distal myopathy has been suggested, on the grounds of a sensory dysfunction, neuropathic findings on neurophysiology and muscle biopsy and a decrease of A-delta nerve fibres on sural nerve biopsy. Genetic analysis has excluded linkage to other defined distal myopathies and hereditary Inclusion Body Myopathy loci.

Adult↗

Charcot-Marie-Tooth disease--muscle biopsy findings in relation to neurophysiology.

Nine patients with Charcot-Marie-Tooth disease with reduced motor nerve conduction velocity (MNCV), i.e. type 1 (CMT1), demyelinating form, and nine patients with Charcot-Marie-Tooth disease with normal or near-normal MNCV, i.e. type 2 (CMT2), axonal form, were subjected to percutaneous muscle biopsy from the anterior tibial muscle in order to characterize histopathological abnormalities and evaluate differences between the two groups. Data from the biopsies were compared with those from 18 age- and sex-matched healthy controls. Muscle biopsies from the CMT1 patients exhibited angular atrophic fibres that were scattered or in small groups, findings commonly described as neuropathic. Muscle biopsies from the CMT2 patients exhibited atrophic fibres that were rounded or elongated in groups and hypertrophic fibres with central nuclei and fibre splitting. There were also increased amounts of connective tissue, 'whorled fibres', degeneration and signs of regeneration, findings commonly regarded as myopathic. In conclusion, muscle biopsies from patients with CMT1 and CMT2 showed markedly different histopathological abnormalities. Possible underlying mechanisms are discussed.

Adult↗

Charcot-Marie-Tooth disease type 1 and 2-an immunohistochemical study of muscle fibre cytoskeletal proteins and a marker for muscle fibre regeneration.

In 10 patients with Charcot-Marie-Tooth disease type 1 (CMT1), hereditary motor and sensory neuropathy (HMSN) type 1, demyelinating form, and 10 patients with CMT2, HMSN type 2, axonal form, monoclonal antibodies directed against dystrophin, spectrin, desmin, vimentin and a myoblast and satellite-cell related antigen, Leu-19, were applied to muscle biopsies from the anterior tibial muscle. Data from the biopsies were compared with those from 20 age- and sex-matched healthy controls. Both CMT1 and CMT2 patients had normal stainings for dystrophin and spectrin, indicating a normal muscle fibre cytoskeletal structure. In the CMT2 group, seven patients had increased staining for desmin in the majority of the atrophic fibres. In the CMT1 group, six of the patients had a normal desmin staining in normal sized and in atrophic muscle fibres, while the remaining four patients had an increased staining for a desmin in a few atrophic muscle fibres. Seven CMT2 patients and one CMT1 patient had increased staining of vimentin in some atrophic muscle fibres. In contrast to CMT1 patients, all CMT2 patients had an increased staining for Leu-19 in a majority of the atrophic muscle fibres. These immunohistochemical data support earlier findings of muscle fibre histopathological differences in CMT1 and CMT2 patients, possible reflecting different pathophysiological mechanisms in the two disorders. Copyright 1998 Lippincott Williams & Wilkins

Journal Article↗

A 9-year longitudinal study of reported oral problems and dental and periodontal status in 70- and 79-year-old city cohorts in northern Sweden.

Before 1981 no representative studies of oral health in an elderly population in northern Sweden had been presented, and longitudinal studies of oral health in the aging person were in general rare. Thus the aim of this study was to investigate longitudinal changes in oral health in a representative sample of an elderly city population in northern Sweden. Reported oral problems and treatment needs were noted, and dental and periodontal status was registered in clinical examinations. The frequency of reported annual dental visits and of being called by the dentist increased in the younger but not in the older cohort during the 9-year period. In 1990 all the 79- and 88-year-olds with annual visits reported that they were recalled by the dentist. The clinical investigation showed an increasing amount of tooth loss, root caries, and periodontal disease with increasing age. Among dentulous persons 1.7 teeth per subject were lost from 1981 to 1990 in the younger cohort, compared with 2.6 teeth per subject in the older cohort. The number of sound teeth decreased very little in the younger cohort (from 3.44 to 3.34) but more evidently in the older cohort (from 3.47 to 2.65) during the 9-year period. The frequency of surfaces with attachment level > 3 mm increased statistically significantly from 1981 to 1990 in the older cohort. Subjects with annual visits had in general fewer oral problems.

Aged↗

Histological indications of a progressive snorers disease in an upper airway muscle.

The etiology of upper airway collapsibility in patients with snoring and obstructive sleep apnea (OSA) remains unclear. Local muscular abnormalities, including neurogenic lesions, could be a contributory factor. The aim of this study was to histologically evaluate the hypothesis of a progressive snorers disease. Biopsies of palatopharyngeal muscle were obtained from 21 patients with habitual snoring and different degrees of upper airway obstruction (10 patients with OSA) and 10 nonsnoring control subjects. Morphological abnormalities, including neurogenic signs (e.g., type grouping), were blindly quantified. The degree of abnormality was significantly increased in patients compared with control subjects. The individual score of abnormalities was significantly correlated to the percentage periodic obstructive breathing but not to oxygen desaturation index. Analyses of the individual fiber-size spectra demonstrated a significantly increased number of hypertrophied and/or atrophied fibers in patients compared with controls. The subjects were also divided into three groups according to their type of nocturnal breathing, i.e., nonsnorers, patients with < 20%, and patients with > or = 45% obstructive breathing. These groups correlated significantly with the degree of abnormality and pathological fiber-size spectra. In conclusion, these results support the hypothesis of a progressive local neurogenic lesion, caused by the trauma of snoring, as a possible contributory factor to upper airway collapsibility.

Adult↗

Influence of thawing method on motility, plasma membrane integrity and morphology of frozen-thawed stallion spermatozoa.

Different thawing methods are used for stallion semen, however, it is unclear which method is the optimal one. To determine if the thawing temperature has an effect on semen quality, we compared 2 thawing temperatures, 75 degrees C and 37 degrees C. The following parameters were used to measure sperm quality: sperm motility, sperm viability, plasma membrane integrity and sperm morphology. Twenty-three ejaculates from 10 Dutch Warmblood stallions were thawed either at 37 degrees C for 30 sec or at 75 degrees C for 7 sec. Sperm motility was evaluated by a Hamilton Thorn Motility Analyser. Plasma membrane integrity and sperm viability were evaluated by using a live/dead fluorescein stain containing a calcein AM probe and ethidium homodimer-1 probe. The eosinaniline blue staining method was used to evaluate the percentage of live and dead cells, as well as sperm morphology. There was no significant difference (P = 0.84) between sperm motility after thawing at 37 degrees C and 75 degrees C. There was also no significant difference (P = 0.053) between the percentage of live spermatozoa using the calcein AM/ethidium homodimer stain after thawing at 37 degrees C and 75 degrees C. There was, however, a significant difference (P = 0.032) between the percentage of live spermatozoa using the eosin-aniline blue stain after thawing at 37 degrees C compared with that at 75 degrees C. In conclusion, our laboratory results indicated that stud farms using frozen semen should thaw the straws at 37 degrees C instead of 75 degrees C. The lower temperature is easier to work with, as thawing at the higher temperature requires special equipment and has to be timed very carefully to avoid damage to the spermatozoa.

Journal Article↗

C4342T-mutation in the SCN4A gene on chromosome 17q in a Swedish family with paramyotonia congenita (Eulenburg)--correlations with clinical, neurophysiological and muscle biopsy data.

Genetic analysis of the adult muscle sodium channel alpha-subunit, SCN4A gene on chromosome 17q, was performed by means of PCR technique in a Swedish family with paramyotonia congenita (Eulenburg) (PMC). The mutation was found in four family members and consisted of a C to T transition affecting the fourth domain of the sodium channel protein. This mutation has earlier been described in other families with paramyotonia congenita. All family members carrying the mutation had cold-induced paradoxical myotonia, myotonic bursts on EMG, and a type IIB atrophy on muscle biopsy. Three of them had slight CK elevation and two had episodes of paralysis. On the basis of clinical findings in this family, persistent proximal muscle weakness, myopathic EMG abnormalities, a type IIB atrophy on muscle biopsy and no symptoms but other signs of muscle affection, were earlier suggested as clinical features of PMC. However, genetic analysis revealed that family members with these symptoms and findings did not have the mutation, indicating that these features are not due to PMC.

Adult↗

Welander distal myopathy is not linked to other defined distal myopathy gene loci.

Welander distal myopathy is an autosomal dominant disorder with late onset that affects extensor muscles of the hands and the feet. The disorder is considered as the most prevalent of the distal myopathies and is almost only seen in Sweden and in some parts of Finland. On clinical, morphological and genetical grounds the disorder is clearly separated from other distal myopathies. We have performed linkage analysis with the MLINK program in a total of six families with microsatellite markers dispersed throughout the genome and report exclusion for the localisation of the gene of 64% of the human genome. These studies have clearly separated Welander distal myopathy from previously mapped forms of distal myopathy such as the Miyoshi myopathy by excluding linkage to chromosome 2. The region on 14q that has been suggested to house the gene of the distal myopathy described by Laing et al. (Am J Hum Genet 1995;56:422-7), has as well been excluded by several markers.

Adult↗

Recombinant human follicle stimulating hormone (r-hFSH; Gonal-F) versus highly purified urinary FSH (Metrodin HP): results of a randomized comparative study in women undergoing assisted reproductive techniques.

A prospective, randomized, comparative, assessor-blind study was carried out in two centres to compare the efficacy and safety of recombinant human follicle stimulating hormone (r-hFSH; Gonal-F) versus highly purified urinary FSH (u-hFSH HP; Metrodin HP), both administered s.c. in women undergoing ovarian stimulation for in-vitro fertilization including intracytoplasmic sperm injection (ICSI). A total of 235 patients started a long gonadotrophin-releasing hormone agonist protocol: 119 received r-hFSH and 114 received u-hFSH HP (150 IU/day) for the first 6 days. Two patients were excluded from the study because they mistakenly received the incorrect treatment combination. Human chorionic gonadotrophin (HCG; 10000 IU, s.c.) was administered once there was at least one follicle 18 mm in diameter and two others > or = 16 mm. In all, 119 (100%) and 102 (89%) of the patients respectively in the r-hFSH and u-hFSH HP groups achieved the criteria for HCG. The mean numbers (+/- SD) of oocytes recovered (the primary endpoint) were 12.2 +/- 5.5 and 7.6 +/- 4.4 in the r-hFSH and u-hFSH HP groups respectively (P < 0.0001). However, the number of FSH treatment days (11.0 +/- 1.6 versus 13.5 +/- 3.7) and the number of 75 IU ampoules (21.9 +/- 5.1 versus 31.9 +/- 13.4) used were significantly less (P < 0.0001) in the r-hFSH group than in the u-hFSH HP group. In patients treated using ICSI (63 patients in each group), no difference in oocyte maturation was observed. The mean numbers of embryos obtained were 8.1 +/- 4.2 and 4.7 +/- 3.5 (P < 0.0001), in favour of the r-hFSH group. In the majority of patients (96 and 99% respectively) only one or two embryos were replaced (mean 2.0 +/- 0.2 and 1.9 +/- 0.1 respectively) in the r-hFSH and u-hFSH HP groups. The clinical pregnancy rates per started cycle and per embryo transfer were 45 and 36%, and 48 and 47%, respectively in the r-hFSH and u-hFSH HP groups (not significant). There were six (5.1%) and two (1.7%) cases of ovarian hyperstimulation syndrome respectively. In conclusion, it was found that r-hFSH was more effective than u-hFSH at inducing multiple follicular development. However, the high rate of low ovarian response in the u-hFSH group compared with our general experience was unexpected. The availability of a gonadotrophin with less inter-batch variation would be beneficial for clinicians. r-hFSH seems to fulfil such a requirement.

Adolescent↗

Muscle fiber atrophy in leg muscles after botulinum toxin type A treatment of cervical dystonia.

Previous electrophysiologic studies on the effects of local injections of botulinum toxin type A (BTX-A) have indicated impaired neuromuscular transmission in distant muscles. To further study possible distant effects of repeated BTX-A injections, we obtained percutaneous muscle biopsies of the vastus lateralis muscle from 11 patients with cervical dystonia. We examined the biopsies with histopathology and morphometry, and compared them with age-matched healthy controls. There was an increased frequency of angular atrophic type IIB fibers in the patient group, and the mean size of IIB fibers was significantly smaller (p < 0.05). In addition, there was a negative correlation between accumulated dose of botulinum toxin and relative size of type IIA fibers (p < 0.05). We postulate that the observed atrophy is due to distant effects of botulinum toxin causing progressive denervation-like changes in non-treated muscle. This observation calls for further, prospective studies of the long-term effects of the treatment.

Adult↗

Proximal myotonic myopathy. Analysis of 3 Swedish cases.

Three Swedish patients with proximal muscle weakness, myotonia and lack of CTG expansion on genetical analysis are presented. Clinical neurological and neurophysiological examination and muscle biopsy were performed. There was an indication of autosomal dominant inheritance in 2 of the 3 patients. The main symptoms and clinical findings in the 3 patients were weakness of the proximal muscles, myotonia, muscle stiffness, muscle pain and muscle atrophy. Neurophysiological examination showed myotonic bursts and muscle biopsy showed a variation of fibre sizes, an increased number of muscle fibres with centralized nuclei and scattered atrophic muscle fibres. Laboratory data showed elevated CK, GT and LD in 1 patient. Before genetical analysis was performed, all 3 patients had been diagnosed as atypical cases of myotonic dystrophy. However, the symptoms, clinical signs, laboratory data, electrophysiological and muscle biopsy findings were compatible with proximal myotonic myopathy (PROMM).

Aged↗