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Biomedical subjects

S Andersson

Publications and source records attributed to S Andersson.

At least 91 records · Page 5Linked to original sources

Male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase 3 deficiency. Diagnosis, psychological evaluation, and management.

Ten male pseudohermaphrodites with 17 beta-hydroxysteroid dehydrogenase 3 (17 beta-HSD3) deficiency were evaluated in 1 clinic with an average follow-up of 10.1 years. The diagnoses were made by demonstrating low to normal serum testosterone levels, high androstenedione levels, and high ratios of serum androstenedione to testosterone in the basal state or after treatment with human chorionic gonadotropin. The molecular features of the underlying mutations were identified in all 7 families. Two additional males in the same families are believed to be affected on the basis of history obtained from family members. All of the 46,XY individuals in these families were registered at birth and raised as females (despite the presence of ambiguous genitalia in all or most), and all virilized after the time of expected puberty due to a rise in serum testosterone to or toward the normal male range. The age at diagnosis varied from 4 to 37 years. Ten individuals were studied by the same psychologist, and change of gender role (social sex) from female to male occurred in 3 subjects and in the 2 presumed affected subjects not studied. The individual with the highest serum testosterone level maintained female sexual identity, and in 2 families some of the affected males changed gender role and others did not. Thus, while androgen action plays a role in the process, additional undefined psychological, social, and/or biologic factors must be determinants of gender identity/role behavior. Management of the 7 individuals who chose to maintain female sex roles included castration, clitoroplasty, vaginal enlargement procedures when appropriate, treatment of hirsutism, cricoid cartilage reduction, and estrogen replacement. Three of the 7 are married (2 twice), 1 is involved in a long-term heterosexual relationship, 1 is engaged to be married, and the other 2 are not married and not believed to be sexually active. The 3 subjects who changed gender role behavior to male underwent hypospadias repair, and 1 was given supplemental testosterone therapy. One of these men is divorced, and the other 2 (aged 29 and 35 years) are unmarried. The diagnosis in 8 of these subjects was made after the time of expected puberty; it is unclear whether the functional and social outcomes would have been different if the diagnosis had been made and therapy begun earlier in life.

17-Hydroxysteroid Dehydrogenases↗

Increased leptin concentration in preterm infants of pre-eclamptic mothers.

AIM: To study the effect of maternal pre-eclampsia on cord plasma leptin concentrations in preterm infants. METHODS: Leptin concentration was analysed in cord plasma of 74 preterm infants, gestational age 24 to 32 weeks. Of these, 14 were born to pre-eclamptic mothers, in 10 intrauterine growth retardation (IUGR) was present, and 59 had been exposed antenatally to corticosteroids. RESULTS: The mean (SD) concentration of cord plasma leptin was 1.31 (0.88) microg/l. A significant correlation was found between leptin concentration and gestational age (r = 0.336; p = 0.0037). Leptin levels were higher in infants of pre-eclamptic mothers (p = 0.0007), in those with IUGR (p = 0.0005), and in infants exposed antenatally to corticosteroids (p = 0.02). In multiple regression analysis, leptin was associated with gestational age and maternal pre-eclampsia (both p < 0.05), but not with antenatal corticosteroids. CONCLUSIONS: Increased fetal leptin in maternal pre-eclampsia may reflect a physiological adaptation to fetal stress such as hypoxia.

Birth Weight↗

Markers of collagen metabolism and insulin-like growth factor binding protein-1 in term infants.

AIM: To study the relation between fetal growth and markers of collagen metabolism and insulin-like growth factor binding protein-1 (IGFBP-1) in term infants. METHODS: Cord vein plasma was obtained from 67 term infants of gestational age 37.1-41.7 weeks (39 appropriate for gestational age (AGA), 11 large for gestational age (LGA; relative birth weight >/= 2.0 SD), and 17 small for gestational age (SGA; relative birth weight </= -2.0 SD)) for analysis of markers of metabolism of collagen type I (PICP and ICTP) and III (PIIINP) and of IGFBP-1. RESULTS: Negative correlations existed between gestational age and PICP (r = -0.294, p = 0.0158), ICTP (r = -0.338, p = 0.0052), and PIIINP (r = -0.432, p = 0.0003). These correlations were also found in SGA infants (all p < 0.05). IGFBP-1 showed negative correlations with birth weight and relative birth weight (r = -0.644, p = 0.0001, and r = -0.693, p = 0.0001 respectively) but not with gestational age (p>0.05). CONCLUSIONS: In the term fetus, collagen metabolism is primarily dependent on maturity and not on intrauterine growth status, whereas IGFBP-1 reflects intrauterine growth independently of maturity.

Biomarkers↗

Cyclooxygenase-2 in human perinatal lung.

Cyclooxygenases-1 and -2 are the key enzymes in the conversion of arachidonic acid to prostanoids. Cyclooxygenase-2 (COX-2) takes part both in inflammation and in control of cell growth. COX-2 immunohistochemistry was performed on lung tissues from autopsies, with four groups included: fetuses (n = 4, GA = 16.0 to 32.0 wk), preterm infants (n = 10, GA = 23.0 to 29.9 wk), term infants (n = 6, GA = 38.7 to 42.0 wk), and infants with bronchopulmonary dysplasia (BPD) (n = 4, GA = 28.9 to 30.7 wk). COX-2 staining occurred exclusively in the epithelial cells resembling type II pneumocytes in the alveolae, and in ciliated epithelial cells in the bronchi. In fetuses, moderate intensity alveolar staining was seen in 90-100% cells lining the alveolar epithelium. In preterm infants, high intensity alveolar staining was seen in a scattered pattern. In term infants, the alveolar staining was also scattered, but with a lower proportion of positive cells. In BPD no staining appeared in alveolar epithelial cells. The most intense bronchial staining was found in fetuses and the least intense in term infants; staining was also seen in BPD. COX-2 is present in human perinatal lung from the gestational age of 16 wk, in a changing pattern. We suggest that COX-2 may, in addition to participating in inflammation, also play a developmental role in the perinatal lung.

Bronchi↗

17beta-hydroxysteroid dehydrogenase type 1 and 2 expression in the human fetus.

The present study investigates the expression patterns of 17beta-hydroxysteroid dehydrogenase (17betaHSD) isozymes in human fetal tissues to understand how estrogenic activity is regulated in the human fetus. Using enzyme assay, high 17betaHSD activity was detected in the placenta and liver, and low levels of 17betaHSD activity were also present in the gastrointestinal tract and kidney. After Northern blot analysis, we detected the messenger ribonucleic acid for 17betaHSD type 1 (17betaHSD1) only in the placenta, whereas that for 17betaHSD type 2 (17betaHSD2) was detected in the placenta, liver, gastrointestinal tract, and urinary tract at 20 gestational weeks. In RT-PCR analysis of the messenger ribonucleic acid transcripts, 17betaHSD 1 was predominantly expressed in the placenta, brain, heart, lung, and adrenal, whereas 17betaHSD2 expression was predominantly detected in the liver, gastrointestinal tract, and kidney. In addition, we detected 17betaHSD2 immunoreactive protein in surface epithelial cells of the stomach, absorptive epithelial cells of the small intestine and colon, hepatocytes of the liver, and interstitial cells surrounding the urinary tubules of the renal medulla. 17betaHSD2 in these tissues may be functioning in the prevention of in utero exposure of the fetus to excessive estradiol from the maternal circulation and amniotic fluids.

17-Hydroxysteroid Dehydrogenases↗

3beta-hydroxysteroid dehydrogenase/delta5-->4-isomerase activity associated with the human 17beta-hydroxysteroid dehydrogenase type 2 isoform.

The type 2 isoform of human 17beta-hydroxysteroid dehydrogenase (17betaHSD2) efficiently catalyzes the oxidative metabolism of androgens and estrogens, and it is expressed in a large series of human peripheral tissues. To obtain a better understanding of the regulation of local steroid biosynthesis and metabolism in human tissues, we have established a dual steroidogenic activity of the 17betaHSD2 enzyme after transfection of human 17betaHSD2-transfected human embryonic kidney (293) cells. After transient transfection, the metabolism of testosterone, pregnenolone, and dehydroepiandrosterone (DHEA) in intact transfected 293 cells was evaluated by TLC-based radiometric assays. 17betaHSD2-transfected cells converted 91% of testosterone (1 micromol/L) into androstenedione in a 2-h incubation period. In addition, pregnenolone (1 micromol/L) was converted to progesterone (18.5%), whereas DHEA (1 micromol/L) was metabolized to androstenedione (8.3% conversion) in a 15-h incubation period. The kinetics of the 3beta-hydroxysteroid dehydrogenase (3betaHSD) and 17betaHSD2 activities using cell homogenate protein of stably transfected 293 cells indicated that the catalytic efficiency (apparent catalytic efficiency = maximum velocity/Km) of this 3betaHSD activity is approximately 2000-fold (pregnenolone as substrate) or 3000-fold (DHEA as substrate) weaker than that of 17betaHSD2 activity. It is noteworthy, however, that the apparent catalytic efficiency of the HSD3B2 gene product is only approximately 50-fold higher than that of the 3betaHSD aspect of the 17betaHSD2 gene product. Pregnenolone or DHEA effectively inhibited 17betaHSD2 activity in a noncompetitive fashion. Furthermore, the potent 5alpha-reductase/3betaHSD inhibitor, 17beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5alpha-androstane-3-one , inhibited neither 3betaHSD nor 17betaHSD2 activities. We conclude that human 17betaHSD2 enzyme exhibits 3betaHSD activity. Notwithstanding that this 3betaHSD activity is reduced compared to 17betaHSD oxidative activity, it may account for at least some of the reports of 3betaHSD activity found in human peripheral tissues that express notable amounts of the 17betaHSD2 isozyme as well as in individuals with severe classic 3betaHSD deficiency.

17-Hydroxysteroid Dehydrogenases↗

Molecular characterization of human immunodeficiency virus (HIV)-1 and -2 in individuals from guinea-bissau with single or dual infections: predominance of a distinct HIV-1 subtype A/G recombinant in West Africa.

Guinea-Bissau in West Africa has the highest prevalence of human immunodeficiency virus (HIV)-2 infection in the world, but recently the HIV-1 prevalence increased rapidly with the subsequent appearance of HIV-1 and HIV-2 dual infections. Information about the genetic subtypes of HIV in the region is limited. Therefore, we characterized the env V3 region of HIV-1 and HIV-2 variants through direct DNA sequencing of peripheral blood mononuclear cell samples from 18 individuals with HIV-1 only and 9 individuals with dual infection. Phylogenetic analyses of these new sequences and database sequences from other West African countries showed that all HIV-1 and HIV-2 sequences from singly as well as dually infected individuals, except one, clustered among HIV-1 subtype A and HIV-2 subtype A, respectively. Importantly, a majority of the HIV-1 sequences from Guinea-Bissau and neighbouring countries were closely related with the isolates IbNG, DJ263, and DJ264, which share a common subtype A/G recombination pattern. Analysis of pol gene sequences from selected HIV-1 variants showed that "IbNG-like" viruses in Guinea-Bissau are also recombinant, indicating that the HIV-1 epidemic in Guinea-Bissau and neighbouring countries is dominated by an epidemic spread of a distinct subtype A/G recombinant, which is strikingly similar to the epidemic spread of a subtype A/E recombinant in Southeast Asia. Furthermore, the HIV-1 and HIV-2 variants carried by individuals with dual infection were intermixed with variants from singly infected individuals, indicating that variants involved in dual and single infections have common epidemiological histories.

Adult↗

HPV typing and HPV16 E6-sequence variations in synchronous lesions of cervical squamous-cell carcinoma from Swedish patients.

We microdissected 15 specimens of invasive cervical cancer co-existing with some of its precursors. Out of 15 cases, 10 carried HPV16, 2 HPV31, 1 HPV18 and 2 were HPV-negative. We found 3 HPV16 E6 variants among the 10 cases; one was A --> G in nt 131 (one case) and a second was A --> G in nt 276. The third, T;--> G in nt 350, was common, and was found in 5 of the 10 patients infected by HPV16. The type of HPV and the E6 variant were identical in all lesions within the same patient. Viral DNA present in normal epithelium was identical in type and E6 variant to HPV in the same patient's lesions. Multiple samples from invasive cancers with HPV were consistently positive. The data suggest that the originally infecting HPV, including its variant type in the E6 gene, persists unaltered in the whole series of CIN that precedes invasive cancer. Our data are compatible with an essential role of HPV manifested by persistence of the viral genome during the entire natural life history of cervical cancer. We did not confirm previous data on the specific association of invasive cancer with an HPV E6 variant (G at nt 350 rather than T). The discrepancy may depend on the relatively few cases investigated or selection of a special sub-set with progression from CIN to invasive cancer already manifest.

Adult↗

Estrogen receptor-dependent regulation of sensory neuron survival in developing dorsal root ganglion.

Estrogen is known to influence different functions in brain tissue ranging from neuronal development to plasticity and survival, but the mechanisms involved have not been defined clearly. Previous studies have shown the presence of the two estrogen receptors (ERs), ERalpha and ERbeta, in several brain areas, but less is known about the role of estrogen in the peripheral nervous system. Here we demonstrate that dorsal root ganglion (DRG) neurons express ERalpha and ERbeta during early postnatal development and in culture, and that the ERs localize mainly to neuronal cell nuclei. Studying the role of estrogen in DRG, we observed that low concentrations of 17beta-estradiol increased survival of cultured DRG neurons deprived of nerve growth factor. 17beta-Estradiol up-regulated the expression of the antiapoptotic molecule Bcl-x without affecting that of Bax, suggesting a mechanism by which the hormone counteracted neuronal death. Antiestrogens abolished the action of 17beta-estradiol in the DRG neurons, which demonstrates an involvement of ERs. The results show that estrogen and ERs play an important role in the development and survival of DRG neurons.

Animals↗

High concordance between polymerase chain reaction and antibody testing of specimens from individuals dually infected with HIV types 1 and 2 in Guinea-Bissau, West Africa.

In this study we have evaluated the concordance between serology, using five commercially available antibody assays designed to discriminate between HIV-1 and HIV-2, and the polymerase chain reaction (PCR) for the detection of HIV-1 and HIV-2 dual infection. Thirty-seven HIV-1 and HIV-2 dually reactive serum samples from individuals in Guinea-Bissau with total CD4+ T lymphocyte counts ranging from 9 to 948 x 10(6)/liter were included in the study. All samples were tested by Multispot, Pepti-LAV, and Immunocomb HIV-1 and HIV-2 discriminatory antibody assays. Thirty-two of the 37 samples were also tested by a combination of two HIV type-specific antibody enzyme-linked immunosorbent assays (ELISA; Wellcozyme HIV-1 and Murex HIV-2). Each sample showed dual reactivity in all or any of these assays. A nested PCR based on primer systems in the vif and pol regions of HIV-1 and in the gag and LTR regions of HIV-2 was used to evaluate the serological results. Thirty samples from HIV-1 antibody-positive individuals and 30 samples from HIV-2 antibody-positive individuals were all PCR positive with their corresponding primer systems. The type specificity was 100% for all of the primer systems. The concordance between dual HIV-1 and HIV-2 reactivity on the serological assays and PCR was 77.7% for Multispot, 80% for Pepti-LAV, 81.8% for Immunocomb, and 85.7% for the two ELISAs used in combination. Thus the majority of individuals included in this study appeared to be truly dually infected. The study shows that it is possible, through a careful selection of assays, to reach a high concordance between serological assays and PCR in studying HIV-1 and HIV-2 dual infections.

CD4 Lymphocyte Count↗

Child survival in children born to HIV-2 infected women in Guinea-Bissau, West Africa.

We have retrospectively studied the effect of maternal HIV-2 infection and other risk factors on child survival at a family planning centre in Bissau, Guinea-Bissau. A total of 2109 women were included, and the seroprevalence of HIV-2 was 5.7%. Overall child mortality of all live births (n=5912) reported by the women (standardized for age of the mother) was slightly higher among children of HIV-2 seropositive mothers (16.3%) compared with children of HIV seronegative women (14.6%) (not significant). There was a significant association between low level of maternal education and increased child mortality, but no difference in the level of education was found between HIV-2 seropositive and seronegative women.

Adult↗

Trends and interaction of HIV-1 and HIV-2 in Guinea-Bissau, west Africa: no protection of HIV-2 against HIV-1 infection.

OBJECTIVES: To study trends in the prevalence and incidence of HIV-1 and HIV-2 infections in Guinea-Bissau over the last 7 years, and to evaluate the protective effect of HIV-2 against HIV-1 infection. DESIGN: Prospective follow-up of a cohort of police officers in Guinea-Bissau, and sentinel surveillance of pregnant women in Bissau. METHODS: Participants in the police cohort were tested regularly for antibodies to HIV and Treponema pallidum, and information about sexual risk behaviour and a history of sexually transmitted diseases was obtained. Simultaneously, pregnant women at the maternity wards at the National Hospital in Bissau were screened annually for HIV antibodies. To evaluate changes in prevalence and incidence of HIV in the police cohort, the study period was divided into three time strata with 2-3 years in each stratum. For the evaluation of a protective effect of HIV-2 on subsequent HIV-1 infection, two multivariate Poisson regression models were constructed, adjusting for different selected confounding variables. RESULTS: Between 1990 and 1997, 2637 police officers were included in the cohort study, 90.7% of whom were male. The overall prevalence of HIV-1 was 0.9%, of HIV-2 it was 9.7% and of HIV-1 and HIV-2 dual reactivity it was 0.5%. For pregnant women the prevalence rates were 0.9, 5.5 and 0.2% for HIV-1, HIV-2 and dual reactivity respectively. The prevalence of HIV-1 increased significantly whereas the prevalence of HIV-2 declined significantly during the study period, among both police officers and pregnant women. The total incidence of HIV-1 and HIV-2 was 0.74 and 0.83 per 100 person-years respectively in the police cohort. The incidence of HIV-1 increased slightly from 0.62 to 0.78 per 100 person-years (not significant), whereas the incidence of HIV-2 declined significantly from 0.90 to 0.35 per 100 person-years over the study period. Seven police officers seroconverted from HIV-2 to dual reactivity (1.22 per 100 person-years). The adjusted incidence ratio of acquiring HIV-1 infection among HIV-2-positive subjects compared with HIV-negative subjects was 1.65 [95% confidence interval (CI), 0.73-3.74] and 1.98 (95% CI, 0.80-4.87), depending on the confounding variables included. CONCLUSIONS: Our study shows an increasing prevalence of HIV-1 and a decreasing prevalence of HIV-2 in Guinea-Bissau. The incidence of HIV-2 declined significantly whereas the incidence of HIV-1 was relatively stable over the study period. No protective effect of HIV-2 against subsequent HIV-1 infection was observed, instead HIV-2-positive subjects had a tendency towards higher risk of acquiring HIV-1 infection compared with seronegative subjects.

Africa↗

Oxidative inactivation of surfactants.

Reactive oxygen species (ROS) may play an important role in the chronic pulmonary morbidity of preterm infants. We therefore studied the magnitude and mechanisms of oxidative inactivation of a natural lung surfactant (NLS) and of two surfactants used for treatment of respiratory distress syndrome, beractant and KL4 surfactant (KL4). Incubation with Fenton reagents, 2-4 mM peroxynitrite (ONOO-) or 0.5 mM hypochlorous acid (OCl-), resulted in an increased minimum surface tension (MST) of all surfactants; the order of effect on MST was beractant > KL4 > NLS. After incubation with Fenton reagents, NLS contained a higher concentration of conjugated dienes (p < 0.01) but lower concentration of malondialdehyde (p < 0.001) than beractant. Protein carbonyl concentrations after treatment with Fenton reagents were higher in NLS and KL4 than in beractant (p < 0. 05). Surface area cycling for 24 h with 2 mM ONOO- or 0.5 mM OCl- caused both beractant and KL4 to increase the proportion of light subtypes from 8-10% to 26-29%; with Fenton reagents, there was disappearance of the light subtype and formation of ultraheavy subtype 74-91% with poor MST. Natural and therapeutic surfactants differ markedly in their sensitivity to ROS, which may be important for surfactants in therapeutic use because oxidative inactivation may limit their effect. Oxidation of natural surfactant may result in reduced function and contribute to chronic lung disease.

Animals↗

Apathy and depressed mood in acquired brain damage: relationship to lesion localization and psychophysiological reactivity.

BACKGROUND: Apathy is a frequent neurobehavioural sequel in patients with acquired brain damage and it may seriously affect outcome of rehabilitation. METHODS: Patients with traumatic brain injury, cerebrovascular insults and hypoxic brain injury, categorized into four lesion localization groups: left hemisphere damage (LHD); right hemisphere damage (RHD); bilateral hemispheric damage (BHD); and subcortical damage (SCD) were assessed with the Apathy Evaluation Scale (AES) and Montgomery and Asberg Depression Rating Scale (MADRS). Heart rate and electrodermal activity were recorded in an experimental situation that exposed the patients to mental stressors in order to measure psychophysiological reactivity. RESULTS: Significant differences in level of apathy were found between diagnostic groups as well as between localization subgroups. SCD and RHD patients displayed most apathy. Factor analysis of MADRS revealed a three-factor solution; depressed mood, somatic symptoms and negative symptoms. Apathy was significantly correlated with negative symptoms in all localization subgroups, except among the BHD patients. Apathy was not correlated with depressed mood or somatic symptoms. Moreover, apathy was significantly correlated with heart rate reactivity, but not with electrodermal reactivity. CONCLUSION: Apathy is common, its severity depending on diagnosis and localization of lesion. Apathy and depression in brain damaged patients share common features, but may be differentiated. The significant relationship between apathy and heart rate may provide a psychophysiological correlation of the disengagement, lack of interest and absence of emotional responsivity typically seen in apathy. The results have implications for the theoretical understanding of apathy and related negative symptoms, and for rehabilitation practice.

Adolescent↗

Comparative evaluation of 14 immunoassays for detection of antibodies to the human T-lymphotropic virus types I and II using panels of sera from Sweden and West Africa.

BACKGROUND: A new generation of assays for the detection of human T-lymphotropic virus types I and II (HTLV-I/II) antibodies has been released. These assays incorporate HTLV-I- and HTLV-II-specific antigens, and some are based on new assay principles. Comparative evaluation data that include these new as well as previous assays are limited. STUDY DESIGN AND METHODS: Fourteen HTLV antibody assays were evaluated by using well-characterized panels of sera from Guinea-Bissau, West Africa, and Sweden. The sera included 127 HTLV-I-positive and 62 HTLV-II-positive specimens, as well as 919 consecutive negative samples. RESULTS: The sensitivity for HTLV-I was 100 percent for all assays, except one, which repeatedly missed one sample. The sensitivity for HTLV-II varied between 86 percent and 100 percent. In general, new-generation assays incorporating HTLV-II-specific antigens, and some of which are based on new assay principles, had a higher sensitivity for HTLV-II than previous assays, which mainly are based on HTLV-I antigens. The specificity was generally higher for new assays than for the previous versions. Testing of Swedish blood donor sera gave higher specificities (94-100%) than did that of African specimens (90-99.7%). Most assays had low delta values (DVs), although there was a tendency toward increased DVs for the new generation of assays. Only two of the new generation of assays came close to a combination of high sensitivity for both HTLV-I and HTLV-II, high specificity, positive and negative predictive values, and high DVs. CONCLUSION: The sensitivity for HTLV-I was generally high and appears to have improved for HTLV-II with the introduction of a new generation of assays incorporating HTLV-II-specific antigens. However, some assays still give false-negative results on HTLV-II-positive specimens. The specificities and the DVs were generally higher for the new assays than for the previous versions.

Africa, Western↗