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Biomedical subjects

S Larsson

Publications and source records attributed to S Larsson.

At least 181 records · Page 10Linked to original sources
PubMed1994

10-year experience with the Biocor porcine bioprosthesis in the aortic position.

Six hundred and nineteen consecutive patients had aortic valve replacement between January 1983 and January 1993 with the zero pressure fixed Biocor porcine bioprosthesis. Mean age was 66.2 years (range 17-88 years). Male/female ratio was 416/203. Concomitant cardiac procedures, mainly coronary bypass surgery, were performed in 35% (214/619). Early mortality was 5.9% (37/619). Late mortality was 15.8% (92/582). Actuarial survival at 10 years was 60.0 +/- 4.9% and freedom from valve-related mortality was 97.6 +/- 0.8%. Total follow up was 2308 years. The follow up was 99.2% complete. Thromboembolic rate was 1.1%/pty (fatal 0.1%/pty, major 0.3%/pty and minor 0.6%/pty). The incidence of prosthetic valve endocarditis was 0.3%/pty (fatal 0.1%/pty). Freedom from reoperation due to structural valve deterioration, non-structural dysfunction and prosthetic valve endocarditis was 78.1 +/- 10.7%, 98.5 +/- 0.6% and 97.6 +/- 0.9%, respectively. The occurrence of structural valve deterioration varied considerably between age groups. In patients below 50 years of age the actuarial freedom from structural valve deterioration was 52.4 +/- 22.0%, while it was 96.2 +/- 1.1% for those between 71 and 80 years. At the 10-year follow up all patients had improved clinically. Preoperatively, 75% of the patients were in NYHA classes III or IV compared to 8% at the 10-year follow up. We conclude, that the Biocor bioprosthesis has a low rate of complications in terms of thromboembolism, anticoagulant-related bleeding, prosthetic valve endocarditis and valve-related mortality as compared to mechanical valves and also to other bioprostheses. The durability of the Biocor bioprosthesis has increased slightly compared to that reported with other, earlier models when inserted in patients above 50 years of age.

Actuarial Analysis↗
PubMed1993

Direct chiral separation of almokalant on Chiralcel OD and Chiralpak AD for liquid chromatographic assay of biological samples.

The four isomers of almokalant, a new antiarrhythmic substance under investigation, were separated by liquid chromatography on a Chiralcel OD and a Chiralpak AD column containing cellulose and amylose tris(3,5-dimethylphenylcarbamate), respectively. Both chiral stationary phases separate almokalant into the four isomers, but the retention orders are different if the carbamate is derivatized on cellulose or amylose. The Chiralcel OD column was used for the separation and determination of the isomers in urine at levels down to 100 nmol/l for the first three eluted and 200 nmol/l for the last with a relative standard deviation of less than 15%. The fluorescence response was increased by post-column ionization after stereoselective separation on the Chiralpak AD column. The isomers of almokalant could be determined at levels down to 10 nmol/l in plasma with a relative standard deviation of less than 15%.

Amylose↗
PubMed1993

Clinical usefulness of serum assays of neuron-specific enolase, carcinoembryonic antigen and CA-50 antigen in the diagnosis of lung cancer.

Serum concentrations of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA) and CA-50 antigen were determined in 168 consecutive patients with lung cancer. All three markers were significantly elevated compared with levels in 102 patients with non-malignant chest diseases. NSE and CEA varied significantly across histological lung cancer types, with most highly elevated serum levels in small cell lung cancer and adenocarcinomas, respectively. The overall diagnostic accuracy was 0.66 for NSE, 0.74 for CEA, and 0.62 for CA-50, implying that CEA best discriminated between lung cancer and benign chest diseases, while CA-50 was less efficient as a diagnostic marker. In multivariate analysis of the three markers combined, a positive predictive value of 95% for lung cancer could be achieved with a diagnostic sensitivity of 57%, with a cut-off level defined as 0.037.NSE + 0.052.CEA + 0.011.CA-50 > 1. In 22% of the cancer patients, the time from admission to histological or cytological lung cancer diagnosis exceeded 1 month. In 52% of these patients, the initial weighted tumour marker index was > 1, strongly implying the cancer diagnosis. The study lends support to the potential use of combined analysis of NSE, CEA and CA-50 as a complementary tool in the diagnosis of lung cancer.

Adenocarcinoma↗
PubMed1993

A survey of Swedish mothers' view on breastfeeding and experiences of social and professional support.

The purpose of this cross-sectional study was to investigate conditions for breastfeeding among 452 mothers. Three different groups of women, participating in the Swedish health care system, were asked to complete a questionnaire about breastfeeding and related issues: 1) pregnant women attending the pregnancy care centres (n = 186), 2) women staying at the maternity wards after delivery (n = 171) and 3) women with two-month-old child attending the child health stations (n = 95). We found that the majority of the mothers were in favour of breastfeeding and intended to or had begun to breastfeed their infants. The main problems were "sore nipples", "children who cannot take the breast" and "insufficient milk production". Negative experiences of previous breastfeeding and overwhelming demands were motives for weaning. The personnel within the health care system were shown to be important for the mothers as regards advice and support. However, we found that certain routines could be revised to strengthen the mothers' attitude towards breastfeeding: 1) information on and discussions about breastfeeding occurred infrequently at the pregnancy care centres. 2) Water or formulated milk was often given to the newborn baby at the maternity wards and 3) the participation of the fathers was limited. Continuous surveillance of the routines and education of the health care staff would be desirable to enable them to give the mothers the right breastfeeding support and advice at the right time.

Adolescent↗
PubMed1993

CD13 (human aminopeptidase N) mediates human cytomegalovirus infection.

Human cytomegalovirus (HCMV) infects cells by a series of processes including attachment, penetration via fusion of the envelope with the plasma membrane, and transport of the viral DNA to the nucleus. The details of the early events of HCMV infection are poorly understood. We have recently reported that CD13, human aminopeptidase N, a metalloprotease, is present on blood cells susceptible in vitro to HCMV infection (C. Söderberg, S. Larsson, S. Bergstedt-Lindqvist, and E. Möller, J. Virol. 67:3166-3175, 1993). Here we report that human CD13 is involved in HCMV infection. Antibodies directed against human CD13 not only inhibit infection but also block binding of HCMV virions to susceptible cells. Compounds known to inhibit aminopeptidase activity block HCMV infection. HCMV-resistant murine fibroblasts have heightened susceptibility to HCMV infection after transfection with complementary DNA encoding human CD13. A significant increase in binding of HCMV was observed in the CD13-expressing transfectants compared with neomycin-resistant control mouse cells. However, murine fibroblasts transfected with mutant CD13, lacking a portion of the aminopeptidase active site, remained susceptible to HCMV infection. Thus, human CD13 appears to mediate HCMV infection by a process that increases binding, but its enzymatic domain is not necessary for infection.

3T3 Cells↗
PubMed1993

Definition of a subset of human peripheral blood mononuclear cells that are permissive to human cytomegalovirus infection.

The identity of cells responsible for transmission of human cytomegalovirus (HCMV) in blood products or bone marrow transplants is unknown. We have tested the capacity of HCMV to in vitro infect human peripheral blood mononuclear cells (PBMC) from healthy donors and found that certain PBMC are permissive to HCMV infection. In vitro-infected viable cells were double stained for surface expression of different HMCV proteins and for cell-type-specific antigens to allow the identification of sensitive cells. All analysis were performed on viable cells, using HCMV-specific monoclonal antibodies and automated flow cytofluorimetry. PBMC were infected either with the laboratory-adapted HCMV strain AD169 or with a virus isolate obtained from a viremic patient. Up to 25% of all PBMC could express the major immediate-early antigen as well as the pp65 antigen, known at the lower matrix protein. Infected cells were mainly CD14+ monocytes, but also a small population of large CD8+ cells were susceptible to HCMV infection. CD19+ B lymphocytes were resistant to HCMV infection. Different populations of infected cells were enriched by using Dynabeads coated with cell-type-specific antibodies, and the presence of infectious virus was demonstrated by incubating the selected and sonicated cell material on human fibroblasts. Only material from infected monocytes and from CD3+ CD8+ cells gave rise to HCMV-specific plaques. The presence of HCMV mRNA as a sign of active viral transcription of the major immediate-early and late pp150 genes in infected cells was demonstrated by using nested reversed polymerase chain reaction. A common denominator was found for all cells that could be infected with HCMV. The CD13 antigen, a 130- to 150-kDa integral membrane protein identical to the enzyme aminopeptidase N, was expressed on all HCMV-permissive cells.

Antigens, CD↗
PubMed1993

The importance of lung function, non-malignant diseases associated with asbestos, and symptoms as predictors of ischaemic heart disease in shipyard workers exposed to asbestos.

The mortality from ischaemic heart disease was studied in a prospective cohort of 1725 shipyard workers exposed to asbestos. The analyses were stratified for age and smoking habits and restricted to men. In agreement with other findings, men with impaired lung function had a significantly higher risk (relative risk (RR) = 3.5) of dying from ischaemic heart disease than men with normal lung function. Men with asbestosis or suspected asbestosis had a significantly higher risk (RR = 3.1) of dying from ischaemic heart disease than men without asbestosis. Thus asbestosis or suspected asbestosis also seemed to be a risk factor for ischaemic heart disease. This finding was independent of respiratory function. There was no increased risk for ischaemic heart disease in men with compared with men without pleural plaques. Men with production of phlegm or sputum and wheezing or whistling had no increased risk for ischaemic heart disease compared with men without these symptoms. In the group with normal lung function men with dyspnoea had a significantly higher risk of dying from ischaemic heart disease than men without dyspnoea. The findings for men with asbestosis or suspected asbestosis indicated a further risk factor besides impaired lung function, in persons exposed to asbestos. Perhaps this risk factor is due to lesions of the pericardium with consequences for heart function.

Aged↗
PubMed1993

Objective and subjective bronchodilation over 12 hours after inhaled formoterol: individual responses.

The aim of the present study was to compare the duration of bronchodilation obtained with 12 micrograms formoterol and 24 micrograms formoterol with that of 200 micrograms salbutamol over 12 hr. Thirteen stable asthmatics (mean age 59 years, asthma duration 7 years, mean FEV1 56% predicted, and reversibility to beta-adrenoceptor stimulation 36%) were studied in a double-blind crossover study. Lung function test (FEV1 and FVC), heart rate, tremor, and subjective effects were recorded before and 30 min after the test doses and every hour up to 12 hr. The test doses were randomized and given double-blindly as two puffs using a spacer. The median duration of effect, defined as time when FEV1 fell below 20% the maximum bronchodilating capacity, was longer than 12 hr for both formoterol doses, whereas it was 7 hr for salbutamol (p < 0.01). No difference between the two doses of formoterol was seen. The median of the patients' subjective evaluation of the duration of effect was 12 hr, more than 12 hr for 12 and 24 micrograms formoterol, respectively, and 8 hr for salbutamol (p < 0.01). Only 1 patient needed rescue medication on the 2 formoterol days. However, 6 patients inhaled rescue medication during treatment with salbutamol. There were no differences with regard to heart rate, blood pressure, subjective tremor, or palpitations. Formoterol, 12 micrograms and 24 micrograms, was shown to produce at least 12 hr of bronchodilating effect in most patients. However, there was considerable individual variation in duration of effect.

Aged↗
PubMed1993

Quantitative importance of asbestos as a cause of lung cancer in a Swedish industrial city: a case-referent study.

We wanted to assess the quantitative importance of asbestos as a cause of lung cancer. In a case-referent study, the exposure to asbestos, tobacco smoke and some other occupational exposures were compared between 147 cases of lung cancer (100 men, 47 women), 111 hospital referents, and 109 population referents, all below the age of 75 yrs and living in an industrial city. The attributable risk of lung cancer due to asbestos exposure was 16% in men (95% confidence interval 1-31%). No woman had occupational exposure to asbestos. We conclude that in the mid 1980's tobacco smoking was the major attributable risk, being 95% for men and 78% for women, but that in men asbestos was an appreciable contributing factor in the general population of a Swedish industrial city.

Adult↗
PubMed1993

Identification of blood mononuclear cells permissive of cytomegalovirus infection in vitro.

We conclude that both the experimental strain Ad169 and a CMV isolate obtained from a patient could infect PBMCs in vitro. The identity of infected cells was established as CD14+ monocytes and a small population of CD3/CD8+ large granular lymphocytes. No evidence of sensitivity to infection was obtained in small lymphocytes, in either the B or T cell population. Furthermore, flow cytometric analysis of cells expressing CMV-encoded antigens is a sensitive assay, as is the demonstration of viral RNA using reversed PCR and nested primer pairs. Since three different types of analyses all indicated active production of structural CMV antigens in infected cells, we conclude that monocytes and some CD8+ large lymphocytes might serve as reservoirs for latent CMV infection and might be responsible for the transfer of CMV infection. Presently, it cannot be determined whether PBMCs are indeed sensitive to a primary infection. Direct sequencing of virus isolates from in vitro-infected cells will have to be carried out to settle this issue. However, we favor the explanation that CMV causes a primary in vitro infection, since, as discussed above, various activating substances can induce the expression of CMV-encoded antigens in blood cells from seropositive donors. Finally, we found that the presence of the CD13 marker was a common denominator of all cells sensitive to CMV infection. We are presently attempting to elucidate whether the CD13 molecule is instrumental in the infection of cells by CMV.

Antigens, CD↗
PubMed1992

Control of adenovirus major late gene expression at multiple levels.

Most late adenovirus (Ad) proteins are translated from mRNAs originating from the so-called major late transcription unit (MLTU). These mRNAs are grouped into five families (designated L1 to L5), where each family consists of mRNAs that have co-terminal 3' ends. We have used mutant and wild-type Ad infections to characterize levels at which major late gene expression is regulated. Our results suggest the existence of a novel intermediate stage during a lytic infection where mRNAs from regions L1 and L4 are selectively overexpressed compared to the L2, L3, and L5 mRNAs. Our data suggest that this RNA phenotype reflects the activity of the MLTU at a transient stage immediately following initiation of viral DNA replication. Early during an Ad infection only mRNA from region L1 accumulate. To efficiently accumulate mRNA from regions L1 and L5 both viral DNA replication and late protein synthesis were required. To allow for only viral DNA replication resulted in an extensive premature transcription termination and a preferential mRNA accumulation from regions L1 and L4. The surprising production of L4 mRNA under these conditions was not due to the activation of a novel r-strand promoter located in the vicinity of region L4 or due to a control at the level of RNA transport or stability. Instead our results indicate that in the absence of efficient late protein synthesis 3' end formation occurs preferentially at the L1 and L4 poly(A) addition sites.

Adenoviridae↗
PubMed1992

Straight leg raising test versus radiologic size, shape, and position of lumbar disc hernias.

In 30 patients with a computed tomography-verified lumbar disc herniation, the relation between the straight leg raising test and the size, shape, and position of the hernia was evaluated before, 3, and 24 months after inception of nonoperative treatment. Hernia size was expressed as an index relating it to the size of the spinal canal. The limitation of the straight leg raising test was not related to size or position of the hernia. Before treatment, straight leg raising was equally restricted in patients with sharply pointed or blunt hernias, but after 3 months straight leg raising was less limited in patients with sharply pointed hernias, whereas after 24 months straight leg raising was regularly normalized. Size index was lower for sharply pointed hernias at all three computed tomography scans. A decrease in hernia size over time, irrespective of shape, was not correlated to a concomitant improvement in straight leg raising. It must be presumed that additional factors, such as inflammatory reactions affecting the nerve roots, are of importance for the magnitude of straight leg raising.

Adult↗
PubMed1992

Quantitation of C-reactive protein levels and erythrocyte sedimentation rate after spinal surgery.

C-reactive protein and erythrocyte sedimentation rate were prospectively measured after four types of uncomplicated spinal operations. In all patients, preoperative normal C-reactive protein (less than 10 mg/L) increased, reaching peak levels on the second day after microdiscectomy (46 +/- 21 mg/L) and anterior fusion (70 +/- 23 mg/L), and at the third day after conventional discectomy (92 +/- 47 mg/L) and posterolateral intercorporal fusion (173 +/- 39 mg/L), with normalization in 5-14 days. Peak levels were not related to bleeding, transfusion, operation time, administered drugs, age, or sex. Erythrocyte sedimentation rate increased to peak levels about 5 days after surgery, followed by a slow and irregular decrease, and at 21-42 days after surgery often remained elevated. The rapid decline in C-reactive protein will probably be interrupted by a second rise or persisting elevation if infection occurs. C-reactive protein is presumably a better test than erythrocyte sedimentation rate for early detection of postoperative infection.

Adult↗
PubMed1992

Respiratory failure in scoliosis and other thoracic deformities. A survey of patients with home oxygen or ventilator therapy in Sweden.

Registers covering Swedish patients with home ventilator or long-term oxygen therapy were used to study respiratory failure caused by thoracic deformities. In all, 107 patients were studied. Postpolio scoliosis was found in 47 patients. The age of starting therapy varied between 28 and 80 years. Fourteen patients had thoracic deformities other than scoliosis. The mean scoliotic angle was 135 degrees among the patients with scoliosis, and the mean vital capacity was 26% (range, 13-54%) of predicted normal. The yearly demand for home ventilator or oxygen therapy is calculated to three per million inhabitants. No operated patients had respiratory failure, and no patients were found with idiopathic scoliosis and respiratory failure younger than 30 years of age, which may indicate a preventive effect of corrective surgery on the development of respiratory failure.

Aged↗