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Biomedical subjects

A Eriksson

Publications and source records attributed to A Eriksson.

At least 73 records · Page 4Linked to original sources
PubMed1998

Adverse changes in fibre type composition of the human masseter versus biceps brachii muscle during aging.

The fibre composition of functionally different regions, the superficial and the deep portions, of the human masseter and the biceps brachii muscles of six elderly subjects (mean age 74 years) was studied by morphological and enzyme-histochemical methods. When compared to previous data for young adults, the masseter muscle from elderly subjects showed a significant decrease in the proportion of type I fibres and an increase of type IM and II fibre types, concomitant with muscle fibre atrophy. In the old biceps, there were no changes in the type I fibre proportion and fibre diameter, but a significant decrease in the type IIB fibre content. The present results of changes in fibre composition, in addition to previous findings of functional deterioration of the old masseter, probably reflect a combination of age related degenerative and adaptive processes within the trigeminal neuromuscular system. When compared with previous findings in young adult masseter, it can be concluded that the human masseter muscle differs from limb muscles both in fibre composition and in structural response of the muscle during aging. These differences between the masseter and the biceps brachii muscle suggest muscle specific alterations during aging probably due to differences in genetical control, functional performance and nerve and hormonal influences.

Adult↗
PubMed1998

Transfer of radiocaesium in sensitive agricultural environments after the Chernobyl fallout in Sweden: III. County of Västernorrland.

In 1986 a large number of farms in the Chernobyl-affected area in the county of Västernorrland in northern Sweden were investigated for radiocaesium transfer to grass and cereal grain. The soil surface layer (0-5 cm) in 1986 and the crop products in 1986-1996 were analysed. The aim was to study the impact of soil and crop rotation on sensitivity of 137Cs transfer in a short and long term perspective. In the fallout year 1986 the transfer to grass was usually much higher than to cereal grain. In this year the transfer to grass was usually much higher in the first cut rather than the second cut. The reduction in transfer with year was large but variable with site and with crop sequence. Ploughing was effective in decreasing the transfer of 137Cs to crops. On arable sites in 1986 the transfer to cereal straw was larger at late stem elongation (LSE) than at the maturing stage. Unexpectedly, there was no clear relationship between transfer of 137Cs to the crops and any of the soil characteristics. In 1986 the transfer of 131I to grass and cereals was also investigated on some of the farms. The results are compared with the transfer of 137Cs, 2 months after the Chernobyl fallout.

Agriculture↗
PubMed1998

Identification of domains involved in superantigenicity of streptococcal pyrogenic exotoxin F (SpeF).

A series of 11 synthetic peptides of 30 amino acids, each with 10 amino acids overlap which spanned the entire sequence of streptococcal pyrogenic exotoxin F (SpeF), were employed in proliferation studies on human peripheral blood mononuclear cells (PBMCs). Regions 41-70, 141-170 and 181-210 were identified as important for SpeF-induced lymphocyte activation. Secondary structure predictions of these peptides showed similarities to regions in other superantigens known to be important for T cell mitogenicity. Furthermore, antisera specific to peptides covering amino acids 1-70 and 181-228 were able to inhibit SpeF-induced mitogenicity by 25% when pre-incubated with SpeF prior to PBMC activation.

Adjuvants, Immunologic↗
PubMed1998

Risk of acute suprachoroidal hemorrhage with phacoemulsification.

PURPOSE: To establish whether small incision cataract surgery with phacoemulsification decreases the risk of acute suprachoroidal hemorrhage (ASCH) compared with traditional nucleus expression by extracapsular cataract extraction (ECCE). SETTING: St. Erik Eye Hospital, Stockholm, Sweden. METHODS: A retrospective study was done on the incidence of ASCH in cataract surgery between July 1990 and July 1996. During this period, 37,565 cataract extractions (phacoemulsification and ECCE) were performed at St. Erik Eye Hospital, combined procedures excluded. The criteria for diagnosis were the suspicion of ASCH during surgery and a verified diagnosis via an expulsive hemorrhage into the wound (4 cases), postoperative ultrasonic examination (20 cases), or a choroidal mass on performing ophthalmoscopy together with a postoperative history alluding to the diagnosis (2 cases). RESULTS: Twenty-six eyes were identified with ASCH, including 7 during phacoemulsification and 19 during ECCE. The incidence of ASCH was 0.03% in the 23,213 phacoemulsification cases and 0.13% in the 14,352 ECCE cases. The difference was statistically significant (P = .0003; chi-square test). CONCLUSION: Small incision surgery with phacoemulsification decreased the risk of ASCH in cataract surgery compared with the traditional nucleus expression technique.

Acute Disease↗
PubMed1998

Chlamydia pneumoniae in human abdominal aortic aneurysms.

OBJECTIVES: To investigate the presence of Chlamydia pneumoniae DNA in the wall of infrarenal abdominal aortic aneurysms, and in the wall of non-aneurysmal infrarenal abdominal aortas. DESIGN: Case-control study. MATERIALS AND METHODS: The study group consisted of 40 patients operated transperitoneally for an infrarenal abdominal aortic aneurysm (IAAA) (eight females, 32 males; mean age 69 years, median age 68 years). Specimens from the aneurysm wall were taken peroperatively under sterile conditions. The control group consisted of 40 deceased persons without aortic aneurysms (14 females, 26 males; mean age 71 years, median age 70 years). Specimens from the non-aneurysmal infrarenal aortas (NIAA) were collected within 48 h after death. The specimens from both groups were frozen at -70 degrees C immediately after collection. A nested polymerase chain reaction (PCR) method, using two sets of primers designed to detect a fragment of the major outer membrane protein gene of C. pneumoniae, was used. RESULTS: The detection of C. pneumoniae-specific DNA was significantly higher in the study group (14/40 = 35%) than in the control group (2/40 = 5%); (p = 0.001). No clinical factor predicting the presence of C. pneumoniae in the aneurysm wall, could be found. CONCLUSION: Chlamydia pneumoniae was detected at a significantly higher frequency in the wall of IAAAs than in the wall of NIAAs. Although this finding does not prove that C. pneumoniae causes IAAAs, further studies on the possible role of C. pneumoniae in the pathogenesis of aneurysms should be performed.

Aged↗
PubMed1998

Immunoisolating encapsulation of intrathecally implanted bovine chromaffin cells prolongs their survival and produces anti-allodynic effect in spinally injured rats.

We have previously reported that intrathecal (i.t.) implantation of bovine chromaffin cells has an anti-allodynic effect in a rat model of mechanical and cold allodynia-like neuropathic pain after spinal cord injury. The technique of encapsulation of the cells by a semipermeable membrane has been developed recently. The present study was undertaken to investigate the effects of encapsulated bovine chromaffin cells on the allodynia-like pain in the same model. Capsules with bovine chromaffin cells or control capsules were implanted in the spinal subarachnoidal space in rats. Their response in behavioural tests were recorded for 2 months. At termination, the capsules were explanted and examined morphologically with tyrosine hydroxylase immunohistochemistry. The mechanical allodynia was totally abolished from week 2 after implantation of the cells and throughout the 8-week test period. The abnormal cold response was also attenuated in about half of the animals. The threshold to acute nociceptive stimulation was not affected. Eight weeks after implantation, 60-80% of the encapsulated chromaffin cells were still tyrosine hydroxylase positive. No effects were observed with control capsules. The results indicate that spinal implantation of encapsulated xenogeneic chromaffin cells may be useful in treating some refractory painful states associated with spinal cord injury. Immunoisolation of chromaffin cells by a semipermeable membrane may inhibit immunorejection, prolong the survival of the cells and enhance their anti-allodynic effect. Copyright 1998 European Federation of Chapters of the International Association for the Study of Pain.

Journal Article↗
PubMed1998

Accuracy of irreversible hydrocolloids (alginates) for fixed prosthodontics. A comparison between irreversible hydrocolloid, reversible hydrocolloid, and addition silicone for use in the syringe-tray technique.

One reversible, seven irreversible hydrocolloids and two addition silicones were examined. The aim was to study their ability to reproduce six differently shaped abutments of a full arch stainless steel master model correctly, by measuring: 1) the accuracy of irreversible hydrocolloid impressions with different storage periods of 15 min, 2 h, 24 h and 95 h, reversible hydrocolloid stored 15 min and 2 h, and Type III addition silicones stored 24 h when the syringe-tray technique was used; and 2) whether mixing technique or tray design had any influence of the accuracy of irreversible hydrocolloid impressions. All the tested impression materials had difficulties in producing full arch casts, where the six abutments were correctly reproduced, because 58% of the heights and 45% of the diameters of the occlusal surfaces were shorter than the corresponding distances of the master model. Storage time, mixing technique and tray design were of significant importance for the irreversible hydrocolloids. Concerning the accuracy at the gingival margin, a shorter storage time resulted in improved accuracy, and mechanical mixing without a vacuum and a tray designed similar to a perforated stock tray gave most accurate impressions.

Alginates↗
PubMed1998

Reproducibility of ultrasonic fetal volume blood flow measurements.

The intraobserver reproducibility of ultrasonic volume blood flow measurements in the human fetus was evaluated in this study. A new approach, simultaneous measurement of the vessel diameter and the flow velocity with a pulsed-wave Doppler ultrasound synchronized with a real-time ultrasound phase-locked echo-tracking system, was used to estimate volume blood flow (VBF) in the fetal descending aorta. Measurements were performed in a longitudinal study on 20 normally grown fetuses. Intraobserver reproducibility of repeated estimations of mean blood flow velocities throughout gestation was very good, with high values of intraclass correlation coefficient (IntraCC 0.80-0.91) and low values of coefficient of variation (CV 4-11%). The IntraCC of repeated vessel diameter measurements throughout gestation was low (0.30-0.68), whereas the values of CV were acceptable (< 12%), with the exception of the period between 140 and 167 gestational days (CV > 12%). The lower reproducibility of vessel diameter measurement contributed directly to the relatively low reproducibility of VBF estimations overall (IntraCC 0.25-0.70; CV 17-28%), as these are calculated from a formula using both flow velocity and vessel diameter. Nevertheless, the synchronized approach gives absolute values of vessel diameter, flow velocity and VBF comparable with values reported in the human fetus previously. The new method provides, by taking the vessel wall pulsations into consideration and by measuring diameter and velocity simultaneously, a more complete information on fetal haemodynamics and fetal physiology.

Aorta, Thoracic↗
PubMed1998

Transient Increase in ST-segment Changes at Time of Reperfusion in Acute Myocardial Infarction Treated by Coronary Angioplasty.

PURPOSE: The clinical significance of early ST-segment re-elevation, a so called Òreperfusion peakÓ in patients with acute myocardial infarction (AMI) treated with thrombolysis is unclear. We examined the incidence and significance of early ST-segment re-elevation immediately upon reperfusion in patients undergoing percutaneous transluminal coronary angioplasty (PTCA) where the time of reperfusion can be precisely established. METHODS: Thirty-two patients (6 women, 26 men, age 61.5 +/- 10.2 years) with an AMI, admitted less than four hours after the onset of chest pain, were included. Twenty-four patients were treated with primary PTCA and eight with rescue PTCA. Computerized on-line vectorcardiography was used for continuous ischemia monitoring. A reperfusion peak was defined as an increase in ST-vector magnitude (ST-VM) of > 50 µV, starting within two minutes after the re-opening of the infarct-related coronary artery and followed by an immediate decrease in the ST segment. RESULTS: Primary success was achieved in all treated patients. Twenty of the patients (63%) developed a reperfusion peak. ST-VM before coronary angiography was significantly larger (p = 0.004) and peak enzyme levels were higher (p = 0.014) in patients who developed a reperfusion peak. Thrombolytic treatment prior to rescue angioplasty, time to reperfusion, target vessel, presence of collaterals or medication on admission did not differ significantly between the groups. CONCLUSION: The occurrence of a reperfusion peak during the minutes after the onset of reperfusion is a common finding in patients with AMI treated at an early stage with angioplasty. There is a relationship with the occurrence of a reperfusion peak and the extent of the initial ST deviation (presumably reflecting the myocardium at risk) and peak enzyme levels. The importance of a reperfusion peak for clinical outcome and prognosis is so far not known.

Journal Article↗
PubMed1998

Crash responsibility versus drug and alcohol use among fatally injured and hospitalized motor vehicle drivers in Sweden.

The present study was aimed at determining whether drivers testing positive for drugs and/or alcohol were more often responsible for the crash than the test-negative ones. Data on 241 fatally injured and 102 hospitalized motor-vehicle drivers was collected in Northern and Western Sweden. Blood samples were taken from these drivers and screened for the presence of alcohol, licit drugs, and illicit drugs. A judgment of responsibility, and assessment of the traffic situation and crash characteristics were based on police reports. Alcohol-positive drivers (n = 49) were more often (96% vs. 70%, p < 0.0001) judged to be responsible for the crash than test-negative drivers. Ninety-three percent of the drug-positive drivers were judged to be responsible, but they were not significantly more often responsible than the test-negative drivers. Drug-positive drivers differed from the alcohol-positive drivers in that they more often crossed over to the wrong side of the road and crashed into an oncoming vehicle. The findings support previous studies that reducing the number of drug-positive drivers in traffic is bound to lead to a reduction in crashes resulting in injury. Further analysis with a larger sample is needed to elucidate the association between crash responsibility and drugs other than alcohol.

Accidents, Traffic↗
PubMed1997

[Shortcomings in the coverage of death occurring outside hospitals].

The article consists in a report of physicians' observance of legislative requirements concerning the documentation and investigation of deaths outside hospital, as studied in a series of 973 cases of death occurring in four medium-sized Swedish communities during 1993. The results showed manifest shortcomings in the performance of post-mortem investigations: long delays in submitting the death certificate, negligence in reporting unnatural and unexpected deaths to the police, and inadequate notes in the patients' journals concerning death certification, which relatives had been informed, the circumstances of death, and whether post-mortem examination had been performed. A special checklist would be of value in the documentation adn investigation of deaths occurring outside hospital.

Autopsy↗
PubMed1997

Serotonergic, noradrenergic, and dopaminergic measures in suicide brains.

Concentrations of the three main monoamines (5-HT, NA, and DA), their metabolites (5-HIAA, DOPAC, and HVA), and the serotonin precursor 5-hydroxy-L-tryptophan were simultaneously measured in frontal cortex, gyrus cinguli, and hypothalamus from 23 controls and 18 suicide victims. Overall suicides did not show significant differences with respect to the control group in any of the measured compounds. Significant increases in noradrenaline and dopamine concentrations were noted in the carbon monoxide poisoning suicides, together with a significant increased hypothalamic dopamine in the drug overdose suicides. It is suggested that the suicidal behavior is not related to substantial changes in cortical and hypothalamic monoaminergic function; however, the reported results could be secondary to the rapid effect of hypoxia and of the acute self-administration of certain drugs in specific metabolic pathways.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1997

Intermediate filament proteins in adult human arteries.

BACKGROUND: The cytoskeleton of cells in blood vessel walls contains desmin, vimentin, and cytokeratins. The distribution of these proteins in human vessels is not fully known. We have mapped the distribution of intermediate filament proteins in human arterial walls. METHODS: Monoclonal antibodies targeted at the intermediate filament proteins desmin, vimentin, and cytokeratins were used, and the distribution of these proteins was studied by immunohistochemistry. RESULTS: In the muscular arteries, most smooth muscle cells in the media expressed both desmin and vimentin; in the elastic arteries, the proportion of desmin-labelled cells was lower and preferentially located to the periphery of the media. In general, the desmin immunoreactivity within the intima was weak, but some smooth muscle cells and smooth muscle cells in the musculoelastic layer showed strong immunoreactivity. The vasa vasorum exhibited a heterogeneous desmin-labelling pattern. The vimentin antibodies labelled the endothelium and showed a heterogeneous staining pattern in the other layers of the arterial wall. Cytokeratin was detected in occasional cells in the media of muscular arteries, in many adluminal cells and cell clusters in the coronary intima, and in smooth muscle cells in the media of the elastic arteries. CONCLUSIONS: Vimentin is widely distributed in vascular smooth muscle cells, whereas the distribution of desmin and cytokeratin varies. Each artery studied had an intermediate filament pattern typical for the anatomical location. There were no interindividual variations in the distribution of intermediate filament proteins.

Adult↗
PubMed1997

Refined genetic localization of the Best disease gene in 11q13 and physical mapping of linked markers on radiation hybrids.

Best's macular dystrophy, also known as vitelliform macular degeneration type 2 (VMD-2), is an autosomal dominant eye disorder that causes reduced visual acuity. It generally manifests itself in the teenage years. The gene mutated in VMD-2 patients may provide valuable insight into the biological mechanisms of the far more common disorder age-related macular degeneration. The VMD-2 gene has been localized to 11q13 between UGB and Fc epsilon RI. In order to clone the gene positionally, a large Swedish VMD-2 family dating back to the 17th century was studied for recombinations. Since the last study, another 40 microsatellite markers have been analyzed in the family; the closest centromeric flanking marker, D11S4076, revealed two recombinations and the closest telomeric flanking marker, UGB, revealed one recombination. The recombinations have occurred in affected individuals, which eliminates the potential problem of reduced penetrance. The order and physical distance between 22 markers located at proximal 11q13 were analyzed on the G3 Stanford radiation-reduced cell hybrids. The data suggest that the VMD-2 region flanked by the microsatellite markers D11S4076 and UGB is approximately 980 kb.

Centromere↗
PubMed1997

Prostaglandin synthesis is suppressed by progesterone in rat preovulatory follicles in vitro.

The inducible form of prostaglandin endoperoxide-2 (PGS-2) is transiently induced by activators of the protein kinase A and protein kinase C systems in rat preovulatory (PO) granulosa cells. This induction is suggested to play an important role in the ovulatory process, which shares many of the characteristics of an inflammatory reaction. The purpose of the present study was to explore the role of progesterone (P4) as an "anti-inflammatory" steroid for the regulation of PGS-2 and the synthesis of prostaglandins in the PO follicle. Isolated rat PO follicles were preincubated with different amounts of exogenous P4 before the addition of luteinizing hormone (LH) and 3-isobutyl-1-methylxanthine (IBMX) (LH + 1). Medium levels of prostaglandin E2 (PGE2) were measured by RIA and the protein contents of PGS-1 and PGS-2 were determined by immunoblotting. LH + I. Both the content of PGS-2 and the synthesis of PGE2 were decreased. The content of PGS-1 demonstrated only minor changes in response to P4. These results showed a dual regulation of PGS-2 in the rat PO follicle with both stimulatory and inhibitory pathways. One of the "anti-inflammatory" actions exerted by P4 in the present study was to reduce the expression of PGS-2 and the follicular production of prostaglandins. This action might be of importance for restriction and control of the inflammatory response in the ovulatory process in vivo.

Animals↗
PubMed1997

Natriuretic peptide immunoreactivity in nerve structures and Purkinje fibres of human, pig and sheep hearts.

Atrial natriuretic peptide is a well-described peptide in cardiac Purkinje fibres and has been shown to interfere with the autonomic regulation in the heart of various species, including man. Recently, we detected immunoreactivity for the peptide in intracardial ganglionic cells and nerve fibre varicosities of bovine hearts, by the use of a modified immunostaining technique that induced an improved detection of natriuretic peptides. These findings raised the question as to whether natriuretic peptides are detectable in these tissues in man and other species. The conduction system from human, pig and sheep hearts was dissected processed with antisera against atrial natriuretic peptide and the closely related brain natriuretic peptide. Immunostaining for the brain natriuretic peptide was detected in some Purkinje fibres in all of these species. Interestingly, in pig, sheep and human hearts, some ganglionic cells and nerve fibres showed atrial natriuretic peptide immunoreactivity, particularly in the soma of human ganglionic cells. This is the first study showing immunoreactivity for the atrial natriuretic peptide in nerve structures and for the brain natriuretic peptide in Purkinje fibres of the human heart. The results give a morphological correlate for the documented effects of atrial natriuretic peptide on the heart autonomic nervous system and for the presumable effects of brain natriuretic peptide in the conduction system of man.

Adult↗