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Biomedical subjects

S Larsen

Publications and source records attributed to S Larsen.

At least 145 records · Page 8Linked to original sources
PubMed1995

Urine profiles and kidney histology after ionic and nonionic radiologic and magnetic resonance contrast media in rats with cisplatin nephropathy.

RATIONALE AND OBJECTIVES: The nephrotoxic drug cisplatin has been used successfully in treating some cancers. Patients with suspected carcinoma frequently undergo examinations with contrast media. We examined whether ionic and nonionic radiologic and magnetic resonance contrast media would have any effect on cisplatin nephropathy in rats. METHODS: Urine and serum profiles were monitored for 24 days after intravenous (i.v.) injections of saline, diatrizoate, iohexol, gadopentetate dimeglumine, and gadodiamide in high doses (4.59 mmol/kg body weight) in rats that received a weekly intraperitoneal (i.p.) injection of cisplatin (1 mg/kg) for 10 weeks. There were 10 rats in each group. Another 10 rats injected with both i.p. and i.v. saline served as control subjects. After euthanization, rats' kidneys were removed for examination by light microscopy and electron microscopy. RESULTS: Light and electron microscopy showed severe morphologic changes, including tubular dilatation, atrophy, and necrosis induced by cisplatin; however, the contrast media did not induce any additional morphologic changes. Gadopentetate dimeglumine, diatrizoate, and iohexol significantly increased (3-20 times) albuminuria compared with i.v. saline in cisplatin nephropathy, whereas gadodiamide did not. Albuminuria was highest after diatrizoate injection. All four contrast media caused an immediate and transient significant increase in the excretion of the brush border enzymes alkaline phosphatase and gamma-glutamyltransferase (125-500 times) and the cytoplasmatic enzymes alanine aminopeptidase and lactate dehydrogenase (16-100 times). Compared with saline, the ionic agents significantly increased the excretion of both glucose (two times) and sodium (three to five times), whereas the nonionic agents did not. CONCLUSION: High doses of radiologic and magnetic resonance contrast agents cause temporary dysfunction in rats with cisplatin nephropathy. Gadodiamide caused the least dysfunction and diatrizoate the most.

Animals↗
PubMed1995

Sexual behavior, sexually transmitted diseases, and risk of cervical cancer.

To explore sexually transmitted diseases and sexual behavior as risk factors for cervical cancer, we analyzed data from a population-based case-control study of breast and cervical cancer in Costa Rica. Data from 415 cases of cervical carcinoma in situ, 149 cases of invasive cervical cancer, and 764 controls were included in the analysis. Multivariate analysis showed that lifetime number of sex partners, first intercourse before age 15 years, number of livebirths, herpes simplex virus type 2 seropositivity, and serologic evidence of previous chlamydial infection were predictors of carcinoma in situ. Serologic evidence of previous syphilis was not associated with carcinoma in situ. Predictors for invasive cervical cancer included lifetime number of sex partners, first intercourse before age 15 years, number of livebirths, serologic evidence of previous syphilis, herpes simplex type 2 infection, and chlamydial infection. Cigarette smoking, socioeconomic status, self-reported history of sexually transmitted diseases, and douching were not associated with either carcinoma in situ or invasive cervical cancer.

Adult↗
PubMed1995

Dietary factors and colorectal polyps: a case-control study.

In the case-control study we compared dietary habits among 108 patients with small (< or = 5 mm, n = 26), medium (5-9 mm, n = 48) or large (> or = 10 mm, n = 34) colorectal polyps with 35 healthy age- and gender-matched controls. A food record by weighing during 5 consecutive days was performed. The intake of fat was significantly higher among the patients, in contrast to a significantly lower intake of carbohydrate, dietary fibre and iron, compared with controls. The intake of vitamin C and calcium was shown to be lower among the patients, but this was significant only for women. There was a tendency among the patients to consume a lower-antioxidant, fibre and cereal fibre diet, and a calcium-rich and more cholesterol-rich diet with increasing size of polyps. The patients with the smallest polyps tended to consume less starch. Our results are too preliminary to draw conclusions with regard to the influence of nutritional factors on the size and growth of polyps. However, our risk factors for the presence of polyps are in agreement with previous studies. Further studies taking into account the size of the polyp are needed to corroborate our findings.

Aged↗
PubMed1995

Can a regular leg extension bench be used in testing deficits of the quadriceps muscle during rehabilitation?

Fifty-nine people, 31 healthy subjects with no previous knee injuries and 28 who had undergone an intra-articular anterior cruciate ligament reconstruction 6-12 months prior to testing took part in the study. The subjects were randomly tested bilaterally on a Cybex 6000 isokinetic testing device (ITD) and on an ordinary leg extension bench (LEB). Strength and endurance were tested with both methods. The linear relationships for paired strength and endurance differences between ITD and LEB were found to be acceptable for the operated group. The LEB alone explained 57% and 38% of the ITD outcome for strength and endurance, respectively. The agreement between observed and predicted ITD values based on the LEB measurements was found satisfactory with a positive standardized agreement index. This indicates that the LEB can be used as a helpful tool in evaluation of quadriceps muscle strength deficits.

Adolescent↗
PubMed1995

Respiratory tract infection and bronchial responsiveness in elite athletes and sedentary control subjects.

To assess the effect of physical exercise during an acute respiratory tract infection (RTI) on bronchial responsiveness, methacholine bronchial challenge tests were performed prospectively in 19 nonasthmatic male cross-country skiers and 22 healthy control subjects with minimal physical activity. Twelve skiers and 10 controls contracted RTI and were studied before and 1, 3 and 6 weeks after the onset of symptoms. The skiers were given no restrictions in their training routines during the period of illness. The geometric mean provocation concentration of methacholine causing a 10% fall in the forced expiratory volume in the first second (PC10), was lower 1 week after onset of infection than at the initial test in the skiers. From the level at 1 week, PC10 increased to levels at 3 and 6 weeks after infection. The PC10 values at 3 and 6 weeks were not significantly different from the initial test. No significant changes in PC10 occurred after infection in the control group. No significant changes in pulmonary function tests were found during the study period in either of the two groups. In conclusion, RTI was associated with a transient increase in bronchial responsiveness in athletes performing physical training during the symptomatic period of respiratory illness but not in nonactive control subjects.

Acute Disease↗
PubMed1995

The influence of training intensity, airway infections and environmental conditions on seasonal variations in bronchial responsiveness in cross-country skiers.

The influence of physical training, airway infections and environmental conditions on changes in bronchial responsiveness to methacholine during a training and competitive season was studied in 19 high-performance male cross-country skiers 19-21 years old. The longitudinal changes in the methacholine concentration required for a 10% fall in FEV1 (PC10) were negatively correlated with the changes in the volume of physical activity at an intensity level above 90% of maximal heart rate. The variation in physical activity at this intensity level accounted for 54.8% of the change in PC10. No association was found, however, with regard to physical activity at lower intensity levels. Seasonal variation in PC10 was not associated with the changes in occurrence or duration of airway infections provided that the PC10 measurement was postponed for 3-6 weeks after the onset of a recent infection. Seasonal variation in PC10 seemed not to be associated with variations in ambient levels of air pollutants or aeroallergens. PC10 was lowest at the end of the coldest part of the year. In conclusion, seasonal variation in bronchial responsiveness in high-performance cross-country skiers could to a great extent be explained by changes in the volume of physical activity at a very high intensity level.

Adult↗
PubMed1995

Comparison of polysulphated glycosaminoglycan and sodium hyaluronate with placebo in treatment of traumatic arthritis in horses.

A randomised double blind and placebo controlled clinical study was carried out. Standardbred trotters (n=77), age 3-4 years) with moderate to severe lameness were grouped according to number of affected joints and, within each group, were randomised for treatment with polysulphated glycosaminoglycan (PSGAG), sodium hyaluronate (SH) or placebo for 3 weeks. The horses were inspected weekly with a final examination 2-4 weeks after the end of treatment. Mean initial lameness score was significantly reduced during treatment and at the last examination in all 3 groups (P<0.01). Additionally, the prevalence of sound horses increased significantly from 1 to 3 weeks of treatment and to the last examination in all 3 groups (P < or = 0.03). Comparison of the 2 treatment groups with regard to development of the lameness curve and time until soundness indicated a small, non significant difference in favour of SH. No significant difference was detected between the 2 treatment groups in the prevalences or cumulative incidence of soundness. The study detected a superior effect of the 2 drugs compared with placebo for reduction in lameness score during the treatment period (P=0.03) and the total study period (P<0.01), time until soundness (P=0.04) and the prevalence of sound horses at the last examination (P<0.01). All 3 treatments affected traumatic arthritis in horses, but the SH and PSGAG gave better results than the placebo.

Animals↗
PubMed1995

Serum immunoglobulin G subclasses in patients with ulcerative colitis and Crohn's disease of different disease activities.

BACKGROUND: Different concentrations of immunoglobulin G (IgG) subclass-producing cells in the mucosa of patients with ulcerative colitis and Crohn's disease have previously been described. METHODS: To evaluate serum concentration of IgG subclasses as a tool for diagnosis and disease activity in chronic inflammatory bowel disease, we compared serum concentrations of IgG, IgA, IgM, and immunoglobulin subclasses IgG1, IgG2, IgG3, and IgG4 by means of the radial immunodiffusion technique in 66 patients with ulcerative colitis and in 68 patients with Crohn's disease of different clinical stages. Erythrocyte sedimentation rate, haemoglobin, and serum concentrations of albumin and orosomucoid were also determined. RESULTS: The serum IgG1 concentration in patients with ulcerative colitis was 8.0 g/l significantly higher than in patients with Crohn's disease (6.8 g/l) (p < 0.005), whereas the serum IgG2 concentration in patients with Crohn's disease was 3.8 g/l, significantly increased compared with patients with ulcerative colitis (3.1 g/l) (p < 0.004). In patients with active ulcerative colitis the serum IgA level (2.03 g/l) was significantly lower than that in the patients with less active disease (2.74 g/l) (p < 0.03). No significant differences in serum concentrations of total IgG, IgG3, IgG4, and IgM were found between groups of patients with ulcerative colitis and Crohn's disease. The differences observed in IgG1, IgG2, and IgA concentrations, however, are small. CONCLUSIONS: The serum concentrations of IgG, IgA, IgM, and IgG subclasses are of little value in the diagnostic procedures in individual patients and are not superior to conventional laboratory tests such as sedimentation rate and serum concentrations of orosomucoid and albumin.

Adult↗
PubMed1995

Reproducibility of the WHO classification of glomerulonephritis.

The inter-observer variation of the WHO classification of glomerulonephritis (GN) was studied using Kappa statistics. One hundred renal biopsies were selected with almost equal representation of the following types of GN: minimal change nephropathy, membranous GN, focal proliferative GN, diffuse mesangial proliferative GN, endocapillary GN, membranoproliferative GN, and crescentic GN. Slides stained with silver-methenamine and PAS-hematoxylin were circulated among the members of the panel, who made their diagnoses without knowing those of the other participants and without knowledge of the clinical conditions. There was a very good overall diagnostic agreement of 0.67 with a Kappa value of 0.61, figures which compete very well with other diagnostic systems analysed with Kappa statistics. Analysing the single types of GN, we found that the highest Kappa values were obtained for crescentic GN (0.81), endocapillary GN (0.79) and membranous GN (0.74) and the lowest Kappa values for membranoproliferative GN (0.40) and diffuse mesangial proliferative GN (0.44). Basically, the international classification of GN is founded upon light microscopy. Our results demonstrate that this system works generally well. The diagnostic reproducibility of the types with less satisfactory Kappa values can be expected to be improved by including immunopathology and electron microscopy.

Biopsy↗
PubMed1995

Influence of dietary factors on weight change assessed by multivariate graphical models.

OBJECTIVE: To analyse the influence of dietary factors on weight changes in a multifactorial context by use of graphical models. DESIGN: Two age-stratified cohorts of Danish men and women were examined twice with five years interval. SETTING: The Glostrup Population Studies in the Copenhagen County, Denmark. SUBJECTS: A random population sample of 2009 men and women, aged 30, 40, 50, and 60 years. METHODS: At baseline all underwent a general health examination including measurement of height and weight, and they completed questionnaires regarding familial predisposition, cohabitation, school education, vocational training, social class, smoking habits, physical activity during work and leisure time, and parity. Dietary intake was evaluated by 7-day food records, allowing estimation of total energy intake and intake of fat and alcohol. At the follow-up examination height and weight were measured again and at each examination BMI was calculated. The statistical analysis was performed by graphical models based on multidimensional contingency tables defined by independence graphs, these may include several categorial or ordinal scale variables and include the assumed temporal relationship between the variables. RESULTS: BMI at entry depended on familial predisposition to obesity, and for women on cohabitation as well. At follow-up 5 years later, BMI in the male group was only related to former BMI, whereas in the female group it was influenced by parity as well. There were several significant associations between the dietary factors, other life style habits and social factors. However, no significant associations were found between total energy intake, percentage of energy from fat or from alcohol and weight changes. For neither gender was there any significant influence of other putative determining factors. CONCLUSION: No influence of dietary factors on weight changes were found when assessed in the context of many other putative determinants of weight change.

Adult↗
PubMed1994

The response of symptomatic neurosyphilis to high-dose intravenous penicillin G in patients with human immunodeficiency virus infection.

BACKGROUND: Infection with the human immunodeficiency virus (HIV) may affect both the natural course of syphilis and the response to treatment. We examined the response to treatment with high-dose penicillin G in HIV-infected patients with symptomatic neurosyphilis. METHODS: Neurosyphilis was defined by reactivity in serum treponemal tests for syphilis, neurologic manifestations consistent with neurosyphilis, and a positive Venereal Disease Research Laboratory (VDRL) test on cerebrospinal fluid. We identified 11 HIV-infected patients with symptomatic neurosyphilis; 5 had been treated previously for early syphilis with penicillin G benzathine. Patients were treated with 18 million to 24 million units of penicillin G per day administered intravenously for 10 days. Cerebrospinal fluid was examined approximately 6 and 24 weeks after treatment, when the polymerase chain reaction and rabbit inoculation were used to detect Treponema pallidum. RESULTS: In four of the seven patients studied 24 weeks after treatment, the serum titers on rapid plasma reagin (RPR) testing decreased by at least two doubling dilutions, and four patients had reductions in the cerebrospinal fluid titers on VDRL testing or reverted to nonreactive results. In two patients there was no normalization or improvement in serum titers on RPR testing or cerebrospinal fluid titers on VDRL testing, cell counts, or protein concentrations. One patient relapsed with meningovascular syphilis six months after therapy. T. pallidum was detected by the polymerase chain reaction in cerebrospinal fluid from 3 of 10 patients before treatment, but in none of the 10 post-treatment specimens. CONCLUSIONS: In patients with early syphilis who are also infected with HIV, therapy with penicillin G benzathine may fail, and neurosyphilis may develop. The regimen of high-dose penicillin recommended for neurosyphilis is not consistently effective in patients infected with HIV.

Adult↗
PubMed1994

Three-dimensional structure of a recombinant peroxidase from Coprinus cinereus at 2.6 A resolution.

The structure of a recombinant peroxidase from the ink cap, Coprinus cinereus, CiP, is reported to 2.6 A resolution and refined to a R-value of 18.1%. The structure was solved by molecular replacement using the coordinates from a newly published ligninase structure. LiP. CiP crystallizes in space group P2(1)2(1)2(1) with two independent molecules in the asymmetric unit related by the vector 0.29b + 0.5c. The two CiP molecules are structurally identical; each contains two Ca2+ ions in positions equivalent to those found in the LiP structure. Two N-acetylglucosamines and one mannose residue were fitted into the density adjacent to two of the three predicted glycosylation sites. The refinement also included 40 and 41 water molecules, respectively, in the two CiP molecules. The structure of CiP displays a folding very similar to that of LiP. The active sites are almost identical in the LiP and CiP structures. CiP has a much larger opening to the active site than LiP.

Binding Sites↗
PubMed1994

Bolus i.v. nitroglycerin treatment of ischemic chest pain in the ED.

A prospective case series was conducted to demonstrate the safety and efficacy of intravenous nitroglycerin (i.v. NTG) boluses in the treatment of ischemic chest pain (CP) in the emergency department (ED). Patients with CP symptomatic after sublingual nitroglycerin (SL NTG) therapy with a systolic blood pressure (SBP) greater than 95 mmHg were included. Patients were treated with i.v. NTG boluses of 0.05 mg to 0.4 mg during a 1- to 2-minute period per a protocol based on the patient's prebolus SBP. This was followed by a maintenance infusion. Additional NTG boluses were repeated every 5 minutes as needed. The end point of treatment was the resolution of chest discomfort, thrombolysis, or a SBP less than 95 mmHg. There were 16 cases of CP. All 16 patients treated, ie, 5 with acute myocardial infarction and 11 with unstable angina showed significant decrease in chest discomfort after 1 to 2 boluses. Two of five with acute myocardial infarction and 9 of 11 patients with unstable angina had complete relief of chest pain after 1 to 4 boluses. There were no episodes of hypotension (SBP < 90 mmHg) in any of the 16 cases. The judicious use of i.v. NTG boluses administered during a 1- to 2-minute period, in the ED, appears safe and efficacious in patients with CP unresponsive to SL NTG therapy.

Administration, Sublingual↗
PubMed1994

Urine profiles and kidney histology after intravenous injection of ionic and nonionic radiologic and magnetic resonance contrast media in normal rats.

RATIONALE AND OBJECTIVES: Previous studies showed that both high-osmolality and low-osmolality iodinated contrast media cause temporary albuminuria and enzymuria (presence of enzymes in urine) in normal rats. Whether the same is true with ionic high-osmolality and nonionic low-osmolality magnetic resonance (MR) contrast media is unknown. We studied urine profiles and histology after intravenous injection of four types of contrast media in rats with normal kidneys. METHODS: Urine profiles were monitored 4, 24, 48, and 72 hr after intravenous injection of saline, diatrizoate, iohexol, gadopentetate dimeglumine, and gadodiamide (4.59 mmol/kg of body weight) in normal rats. Each group included 20 male rats. After sacrifice, both kidneys were removed for examination by light microscopy (LM) and electron microscopy (EM). RESULTS: All four contrast agents caused a temporary (< 22 hr) increase in the excretion of albumin (2-5 times) and of cytoplasmic (30-100 times) and brush border (10-100 times) renal enzymes when compared with saline. The degree of albuminuria correlated well (r = 0.90) with the osmolality of the injected media, whereas the increased level of enzymuria was unrelated to the osmolality. No major differences in the enzymuric effects of the four agents were noted. LM revealed vacuoles in all kidneys exposed to radiologic contrast media but not in kidneys exposed to MR contrast media or saline. Slight vacuolation was revealed by EM after the use of MR contrast media, and significant vacuolation was evident via EM after the use of radiologic contrast media. No difference between ionic and nonionic media within each drug group was detected by either LM or EM. CONCLUSIONS: Transient renal effects are induced by both ionic and nonionic high-osmolality and low-osmolality radiologic and MR contrast media in normal rats. Both osmotic (e.g., albuminuria) and chemotoxic (e.g., enzymuria) mechanisms seem to be involved. From a morphologic point of view, the chemotoxic mechanisms seem to be of major importance.

Animals↗