Biomedical subjects

B Lindblom

Publications and source records attributed to B Lindblom.

At least 37 records · Page 2Linked to original sources

PubMed2000

Concordance between results of optic disc tomography and high-pass resolution perimetry in glaucoma.

PURPOSE: To evaluate concordance between results obtained with the Heidelberg Retina Tomograph (HRT) (Heidelberg Engineering GmbH, Heidelberg, Germany) and those obtained with the high-pass resolution perimeter (HRP) in glaucoma diagnosis. METHODS: A total of 217 patients from the glaucoma services at St. Erik Eye Hospital, Stockholm, Sweden (n = 107) and Sahlgrenska University Hospital, Göteborg, Sweden (n = 110) were included in the study. All patients were examined because of known or suspected glaucoma in at least one eye. The conventional indices presented by the instruments were used, i.e., glaucoma index from the HRT (negative values = abnormal, positive = normal) and combined deviation (upper normal limit 2.1 dB) from the HRP. RESULTS: The concordance regarding the classification of normal or glaucomatous by the two instruments was 71% (153/217 eyes). The HRT indicated glaucoma but HRP findings were normal in 47 patients, and the reverse occurred in 17 patients. There was a significant difference in optic disc area between patients with abnormal HRT findings and normal HRP findings and in patients with normal HRT findings and abnormal HRP findings. The concordance could not be improved by adjusting for disc size. The correlation between combined deviation on HRP and the HRT glaucoma index was r = -0.53. CONCLUSION: A significant correlation was found between the combined index given by HRP and the HRT glaucoma index in 217 patients examined for known or suspected glaucoma. Discordant findings were observed in 64 patients; in 22 this discordance was explained by the influence of disc size. No other reasons for differences in examination results could be detected.

Aged↗

PubMed2000

Human uterine myocytes retain their energy charge with No gross alterations in morphology for at least 8 days when cultured under anaerobic conditions.

OBJECTIVE: To investigate the ability of human uterine myocytes to grow under anaerobic conditions for a prolonged time period. METHODS: Cells were isolated from fundal myometrium and cultured until subconfluency. The cell type was confirmed by immunostaining for the smooth muscle cell-specific cytoskeletal proteins alpha-actin and desmin. Some cells were further cultured under aerobic conditions and others under anaerobic conditions. Cells were harvested after 0, 4 and 8 days in culture and analyzed for their content of adenylates. RESULTS: Immunostaining revealed that all three preparations contained almost only smooth muscle cells. Energy charge of the myocytes was 0.88 on average at the beginning of the culture experiment. A moderate decrease was noted on day 4 for myocytes grown under both aerobic and anaerobic conditions and no further decrease was noted between days 4 and 8. Morphologically the cells retained their normal appearance and they seemed healthy for at least 8 days in culture under both aerobic and anaerobic conditions. CONCLUSIONS: The results of this study suggest that human myometrial cells can survive for an extended period of time under in vitro conditions regardless of oxygen availability for energy metabolism. This means that anaerobic energy metabolism is enough to sustain vital processes during that period of time.

Actins↗

PubMed2000

Apoptosis, cellular proliferation and expression of p53 in human uterine leiomyomas and myometrium during the menstrual cycle and after menopause.

BACKGROUND: Cell proliferation, apoptosis and expression of p53 proteins were studied in human uterine leiomyomas and myometrium during the menstrual cycle and after menopause. METHODS: Expression of ki-67 and p53 was analyzed by immunohistochemistry and by immunoblotting. Apoptosis was detected by in situ 3' end labelling of cells with DNA fragmentation. RESULTS: In both the proliferative and the secretory phases, ki-67 expression was higher in leiomyomas than in myometrium and both tissues showed higher expression in the secretory than in the proliferative phase. No difference in apoptotic index was observed between leiomyomas and myometrium or between the proliferative and secretory phases. After menopause, the expression of ki-67 as well as the apoptotic index was lower than in the proliferative and secretory phases and no significant difference between tissues was seen. Both leiomyomas and myometrium showed negative staining for p53. Immunohistochemical results regarding p53 were confirmed by Western blot. CONCLUSIONS: Our findings indicate that sex steroids influence the growth of leiomyomas by stimulating cell proliferation rather than by affecting apoptosis. The rate of cell proliferation is higher in fertile age than after menopause and appears to be enhanced under the influence of progesterone.

Adult↗

PubMed1999

The action of vasoconstrictive agents on human tubal arteries.

The aim of this investigation was to compare the response of small arteries of the human tubo-ovarian vasculature to certain vasoactive agents. Ring preparations of the arteries were isolated and mounted in tissue chambers for isometric recording of wall tension. The arteries were exposed to the vasoactive agents adrenalin, prostaglandin F2 alpha and two vasopressin analogues. Adrenalin, prostaglandin F2 alpha, lysin-vasopressin and triglycyl-lysine-vasopressin all produced powerful vasoconstriction, the greatest efficacy being shown by and lysine-vasopressin. The maximum response occurred after addition of a third compound to a combination of two, irrespective of which combination was used. Adrenalin showed faster contraction velocity than the other agents. The results indicate that the human tubo-ovarian arteries may be constricted by a variety of physiological and pharmacological stimuli, at least partly acting via different effector mechanisms. It is proposed that these vasoconstrictive agents--alone or in combination--may be useful in conjunction with gynaecological endoscopic surgery, e.g. in tubal pregnancy or ovarian cysts.

Arteries↗

PubMed1999

Cell characteristics and function of two enriched fraction of human luteal cells prolonged culture.

Two subpopulations of steroidogenic cells exist in the corpus luteum of most species. The aims of the present study were to characterize these cells and to study their function during long-term culture. Human corpora lutea from early and late luteal phases were treated by mechanical and enzymatic digestion, followed by density sedimentation. Five distinct cell bands were obtained, two of which produced large amounts of progesterone. These were characterized according to density, size, steroidogenic enzymes, and numbers. More than 75% of cells expressed immunoreactive 3beta-hydroxydehydrogenase (3beta-HSD). Cells of higher density/smaller size were obtained in increasing numbers during the luteal phase and were more numerous compared with large cells. Under basal, human chorionic gonadotrophin (HCG)-, and prostaglandin E(2)-stimulated culture conditions, progesterone synthesis was greater in large cells of the early, but not late, luteal phase. Both cell fractions obtained from late, in contrast to early, luteal phase increased their basal progesterone production during the culture period of 9 days. We conclude that this technique for luteal cell isolation in the human yields two distinct subpopulations of steroidogenic cells, which respond differently to luteotrophic stimuli. We also conclude that cells of late luteal phase readily increase their progesterone synthesis over a period of 9 days, indicating a transition to longevity.

Cell Size↗

PubMed1998

Screening for chlamydial infections and the risk of ectopic pregnancy in a county in Sweden: ecological analysis.

OBJECTIVES: To analyse trends in rates of genital chlamydial infection and ectopic pregnancy between 1985 and 1995 in a county in Sweden. SETTING: Uppsala county where screening for chlamydial infection, treatment, and contact tracing has been widespread and where ectopic pregnancies are recorded. METHODS: Rates of chlamydial infections and ectopic pregnancy between 1985 and 1995 were calculated for women aged 20-39 years. Poisson and linear regression were used to examine the association between the risk of ectopic pregnancy and the current rates of chlamydial infection and rates of chlamydial infection from up to 5 years earlier. MAIN OUTCOME MEASURES: Rates of chlamydial infection per 100 examinations, rates of ectopic pregnancy per 1000 pregnancies, rate ratios and 95% confidence intervals for an increase in chlamydial infections of 5 new cases per 100 examinations. RESULTS: 103 870 cervical samples from women aged 15-39 years were analysed; 5648 (5.4%) were positive for chlamydia. 51 630 pregnancies were analysed; 930 (1.8%) were ectopic. Both rates declined over time. For women aged 20-24 years there was a strong correlation between the rate of ectopic pregnancy and the rate of chlamydial infection in the same year (r=0.93, P<0. 001); among older women correlations were stronger with rates of chlamydial infection occurring 1 or 2 years earlier. In Poisson regression ectopic pregnancy was most strongly associated with the current rate of chlamydial infection among women aged 20-24 (rate ratio 1.85, 95% confidence interval 1.44 to 2.38), with the rate of infection 1 year earlier among 25-29 year olds (rate ratio 1.72, 1. 33 to 2.22) and 30-34 year olds (rate ratio 2.27, 1.53 to 3.37); and with the rate 2 years earlier among 35 to 39 year olds (rate ratio 2. 58, 1.45 to 4.60). CONCLUSIONS: Declining rates of genital chlamydial infections have probably led to a fall in the rate of ectopic pregnancies. The timing of the decline in the rate of ectopic pregnancies varies with age. Among young women falling rates of chlamydial infection have been accompanied by an immediate reduction in the rate of ectopic pregnancy.

Adolescent↗

PubMed1998

The prognosis of idiopathic choroidal neovascularization in persons younger than 50 years of age.

OBJECTIVE: To examine the prognosis of idiopathic choroidal neovascular membranes in patients younger than 50 years of age at the time of diagnosis. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Eighteen consecutive patients from a university clinic (20 eyes) with idiopathic choroidal neovascularization in the macular area. All patients diagnosed between 1979 and 1996 were included; follow-up time varied from 5 to 187 months (mean, 55 months). INTERVENTION: Treatment was conservative. All patients were informed about argon laser photocoagulation, but in the majority of cases, patients were not encouraged to undergo such treatment. Treatment was given on patient's request. MAIN OUTCOME MEASURES: The dimensions of the choroidal neovascular membrane and its distance to the foveola were determined by computerized image analysis and their correlation with final visual acuity determined. RESULTS: Fifteen (75%) of the 20 eyes retained a visual acuity of 20/60 or better. In ten eyes (50%), acuity was 20/25 or better. Six eyes had been treated with laser photocoagulation; only one had a membrane located 200 microns or more from the foveola at the time of treatment. The outcome for treated eyes was no better than for untreated eyes, although the two groups were not directly comparable. In no eye did an initially juxtafoveal or extrafoveal membrane continue to grow under the foveola. CONCLUSIONS: The prognosis of idiopathic choroidal neovascularization was much better than reported previously for eyes with choroidal membranes associated with age-related macular degeneration. A conservative treatment regimen should be considered. The authors have no reason to believe that laser photocoagulation would have improved the outcome in the nontreated eyes.

Adult↗

PubMed1998

Synthesis, in vivo rhesus monkey biodistribution and in vitro evaluation of a 11C-labelled potent aromatase inhibitor: [N-methyl-11C]vorozole.

[N-methyl-11C]Vorozole, a high-affinity aromatase-binding radiotracer, was synthesized through N-methylation of the corresponding nor-vorozole derivative using [11C]methyl iodide. [N-methyl-11C]Vorozole was obtained in 53-56% radiochemical yield based on [11C]methyl iodide within 40 min of the end of radionuclide production. The final formulation was >98% radiochemically pure and had a specific radioactivity of 10-143 GBq/micromol. In vitro, [N-methyl-11C]vorozole displayed high and specific binding to aromatase-rich human placenta. [N-methyl-11C]Vorozole binding to other tissues was lower and less specific. The dissociation constant measured was in the low nM range (Kd 1.7 nM), consistent with published Ki values for vorozole. Biodistribution studies in rhesus monkeys showed high liver uptake, which reached a constant level of 20% of the injected dose after 10 min, and an otherwise relatively even distribution of radioactivity. Pretreatment with vorozole only caused minor alterations of the biodistribution of the tracer.

Animals↗

PubMed1998

Fluorescein angiography of the iris in the management of eyes with central retinal vein occlusion.

PURPOSE: To study fluorescein angiography of the iris as a means of identifying eyes at risk for developing secondary glaucoma after central retinal vein occlusion. METHODS: Fluorescein angiography of the iris was performed with a scanning laser ophthalmoscope in 27 patients (27 eyes). Individual images were by computer, determining relative areas of fluorescein staining and leakage. RESULTS: The best predictor of secondary glaucoma was the relative area showing staining. Neither relative area of leakage nor presence of iris rubeosis, age, or initial visual acuity were effective means of predicting which eyes would develop secondary glaucoma. This occurred in six eyes; all were treated with argon laser photocoagulation. No eye was enucleated. CONCLUSION: Iris angiography can identify eyes at risk for secondary glaucoma but specificity is poor. The often recommended regime to perform laser photocoagulation in all eyes with iris neovascularisations was challenged.

Adult↗

PubMed1998

Open angle glaucoma and non-central retinal vein occlusion--the chicken or the egg?

PURPOSE: To determine whether non-central retinal vein occlusion (nCRVO) or open angle glaucoma (OAG) is the primary event in eyes suffering from both diseases. METHODS: The study has two parts. The first is a retrospective survey of a clinical glaucoma database. In eyes with OAG and nCRVO, the temporal relationship between the conditions was determined when possible. The second part is a ten-year follow-up study of eyes with isolated nCRVO. RESULTS: Study 1: Among 576 OAG patients, 25 (4.3%) had nCRVO. In all eyes except one, OAG occurred before nCRVO. Almost without exception a vein on the optic disk or at the disk margin was occluded. Study 2: Most eyes with isolated nCRVO had an occluded vein at a retinal artery-vein crossing. Only one of 34 patients had developed OAG after ten years. CONCLUSIONS: This study suggests that OAG in most eyes is the primary event. nCRVO had different characteristics in eyes with OAG compared to eyes without OAG.

Adult↗

PubMed1998

Scanning laser ophthalmoscopy as a tool for detecting atrophy of the central retinal nerve fibre layer in Leber's hereditary optic neuropathy.

PURPOSE: To study the central retinal nerve fibre layer with scanning laser ophthalmoscopy (SLO) in subjects with Leber's hereditary optic neuropathy (LHON), a disease primarily affecting retinal nerve fibres in the macular area. METHODS: SLO was performed using combinations of laser wavelengths and aperture settings in subjects with LHON and in age-matched normal controls. RESULTS: Six subjects with LHON were examined. The reduction of central retinal nerve fibre layer was clearly demonstrated on the SLO images. Consistent findings were abnormal visibility and apparent broadening of perifoveal blood vessels. In all six normal controls the temporal nerve fibre raphe could be demonstrated. CONCLUSIONS: SLO imaging is an easy way of depicting the central retinal nerve fibre layer, requiring no special photographic skills. The demonstration of nerve fibre reduction is valuable in the early diagnosis of LHON.

Adolescent↗

PubMed1998

Preoperative measurements of macular hole with scanning laser ophthalmoscopy. Correlation with functional outcome.

PURPOSE: To measure the dimensions of macular holes before surgery and compare them with the functional outcome. METHODS: A prospective study of ten consecutive patients scheduled for macular hole surgery. Macular holes were imaged with scanning laser ophthalmoscopy with different laser wavelengths. Computerized image analyses were used to measure the size of the hole and the surrounding rim. RESULTS: Eyes were referred to three different groups preoperatively according to visual function. Measurements of the longest diameter and the area of the macular hole were found to correlate well with visual function tested before and after surgery. All holes closed after one operation. Eighty per cent of eyes improved two or more lines on the distance visual chart and all patients but one could read a newspaper six months after surgery. CONCLUSION: Preoperative size of macular hole can be used as a predictor of the functional outcome of macular hole surgery.

Aged↗

PubMed1998

Falloposcopy in conjunction with laparoscopy: possibilities and limitations.

Falloposcopy is a transvaginal microendoscopic technique to explore the human Fallopian tube from the uterotubal ostium to the fimbrial end. Falloposcopy provides a unique possibility to visualize endotubal disease and may be used therapeutically for removal of debris and for cutting down filmy intraluminal adhesions. To assess the clinical performance of falloposcopy as part of an infertility investigation, a total of 43 women scheduled for laparoscopy as part of an investigation of infertility had a falloposcopy performed in conjunction with the laparoscopy. All women were investigated at Danderyd Hospital, Stockholm and Akademiska Hospital, Uppsala, during 1995 and 1996. Images from the endosalpinx were obtained in 26 of 43 women (60.5%). In 10 women (23.3%), it was possible to obtain images from both tubes. No images were of sufficient quality to describe the entire tubal mucosa in detail. Falloposcopy represents a unique tool for visualization of endotubal disease and may provide a valuable instrument for in-vivo exploration of tubal physiology. However, certain technical problems limit the usefulness of this method in routine clinical practice. These technical problems have to be solved before falloposcopy can achieve a central position in investigation and treatment of tubal disease.

Adult↗

PubMed1998

Haplotypes comprising subtypes of the DQB1*06 allele direct the antibody response after immunisation with hepatitis B surface antigen.

Two HLA class II haplotypes, HLA-[DQB1*0602; DQA1*0102; DR15] and HLA-[DQB1*0603; DQA1*0103; DRB1*1301] were found to be less common in 52 nonresponders compared with 68 responders, P<0.025 and P<0.05 respectively, after vaccination with hepatitis B surface antigen (HBsAg). Another haplotype, HLA-[DQB1*0604; DQA1*0102; DRB1*1302], had a significantly higher frequency in the nonresponders (P<0.005). The nonresponders and responders were nonsmoking, healthy individuals with an antibody concentration of <10 IU/l and >100 IU/l respectively. The three haplotypes comprise either of three different DQB1*06 subtypes. Two of the seven amino acids that differ between the two responder alleles DQB1*0602 and *0603 and the nonresponder allele *0604 are located in the peptide-binding groove of the DQB1 molecule. In addition to this finding, amino acid 86 in the DRB1 molecule seems to determine the response against HBsAg. DRB1*1301 and DR15 in the responder haplotypes have a Val at this position while the nonresponder haplotype has a Gly. These results suggest a role for both the DQB1*06 alleles and the DRB1 alleles *1301, *1302 and DR15 to direct either a response or a nonresponse against HBsAg. Sixteen HLA class II genotypes were found to be shared by 25 nonresponders and 32 responders. This finding of HLA-identical nonresponders and responders indicates an influence of other genetic factors in addition to the HLA system in the response to HBsAg.

Adult↗

PubMed1998

Sex steroid receptors in human myometrium and fibroids: changes during the menstrual cycle and gonadotropin-releasing hormone treatment.

The content of estrogen and progesterone receptors (ER, PR) is higher in fibroid tissue than in homologous myometrium, and both receptors seem to be regulated by the levels of circulating sex steroids. Myometrial and fibroid tissues were recovered from women undergoing gynecological operations during different phases of the menstrual cycle and during treatment with an analogue of GnRH (GnRHa). Contents of ER and PR in the tissue cytosol were determined by enzyme immunoassay. The ER levels were significantly higher in fibroid tissue than in homologous myometrium in all the endocrine conditions. During the secretory phase, when luteal progesterone production is prominent, the ER levels in the myometrium and fibroids were lower than during the proliferative phase. During GnRHa treatment, the ER levels in both tissues were similar to those in the proliferative phase but significantly higher than in the secretory phase. The PR levels were also significantly higher in fibroids than in myometrium in all the different endocrine conditions. In both tissues, the PR levels were lower in the secretory phase and during GnRHa treatment, compared with the proliferative phase. Our data suggest that, in these categories of women, both ER and PR are overexpressed in fibroid tissue. Apparently, high progesterone levels down-regulate the ER in both fibroids and myometrium, whereas estrogen mediates the up-regulation of the PR during the proliferative phase. Increased knowledge about the mechanisms by which sex steroids regulate their own receptors in uterine tissues might provide a basis for development of new treatment strategies for women with fibroid disease.

Adult↗

PubMed1997

[Growth factors in the uterus are surveyed].

The central localisation of the uterus in the female body may be seen as reflecting its central function in human reproduction, though in rare cases pregnancy may be established even in the absence of uterus. The sex steroids are largely responsible for the central regulation of uterine function, and recent productive research has shown the significance of peptide growth factors for various physiological functions, including the development and repair of the endometrium during the menstrual cycle, as well as the adaptation and growth of the organ during pregnancy. The possible involvement of angiogenic peptides in endometrial neovascularisation is discussed, as is the significance of proto-oncogenes and growth factors for the development of uterine fibroids. Further development in this field may have a variety of clinical implications, including the possibility of promoting or inhibiting implantation by manipulation of endometrial angiogenesis.

Angiogenesis Inducing Agents↗

PubMed1997

A comparison of myogenic and endothelial properties of myometrial and omental resistance vessels in late pregnancy.

OBJECTIVE: Our purpose was to compare myometrial and omental resistance arteries from term pregnant women with respect to myogenic behavior in the presence or absence of a nitric oxide synthase inhibitor and to compare distensibility and acetylcholine-mediated dilatation in these vessels. STUDY DESIGN: Intramyometrial (n = 17) and omental (n = 14) resistance arteries from term normal pregnant women were studied in a pressurized arteriograph system. Myogenic tone was evaluated during increments in intraluminal pressure from 20 to 120 mm Hg with and without inhibition of nitric oxide synthase. Endothelium-dependent relaxation was assessed by evaluating the response to acetylcholine (10(-6) mol/L) in arteries pressurized at 70 mm Hg. RESULTS: Myogenic tone was greater at all pressure steps in the myometrial than in the omental arteries (p < 0.05). Inhibition of nitric oxide synthase with N(omega)-nitro-L-arginine had no influence on myogenic tone in either group. Relaxation to acetylcholine was greater in myometrial (18% +/- 4%) compared with omental vessels (7% +/- 2%, p < 0.05). The passive distensibility (Ca++-free solution and in the presence of papaverine) of arteries from the myometrium and the omentum was similar. CONCLUSION: Normal pregnancy is associated with different mechanical properties of resistance vessels from the two vascular beds studied. Basal nitric oxide release does not modify myogenic tone, at least under no-flow conditions. Acetylcholine-induced relaxation is greater in myometrial than in omental arteries.

Acetylcholine↗

PubMed1997

Lipoprotein(a) and HLA-DRB1 and -DQB1 genes in coronary artery disease.

In some respects, atherosclerosis resembles autoimmune disease. Since many autoimmune diseases are associated with certain histocompatibility leukocyte antigen (HLA) class II alleles, we have looked for a similar HLA association with atherosclerosis. In the first phase, genomic typing was performed in 52 men with coronary artery disease. In the second phase, 50 men with early onset (before 50 years of age) coronary artery disease were studied. 12 DRB1 and 4 DQB1 alleles were determined by restriction fragment length polymorphism analysis. No significant difference in frequency of the examined alleles was observed in any of the patient groups compared to healthy controls. The plasma level of lipoprotein(a) (Lp(a)) is considered an important risk factor for early coronary heart disease. A linkage between inherited high levels of Lp(a) and certain HLA class II genotypes has been suggested. In the present study, Lp(a) levels were measured in men with early onset of coronary artery disease. 11 (23%) Study patients and 3 (7%) control subjects had Lp(a) levels above 450 mg/l. However, no correlation between high Lp(a) levels and certain HLA genotypes was found. Summarized, these findings indicate that atherosclerosis, especially early onset coronary atherosclerosis, is not a disease associated with particular HLA alleles.

Adult↗