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Biomedical subjects

B Möller

Publications and source records attributed to B Möller.

At least 19 recordsLinked to original sources

Optical evaluation of red blood cell geometry using micropipette aspiration.

Although red blood cell (RBC) geometry has been extensively studied by micropipette aspiration, the small size of RBC and pipettes vs. the optical resolution of light microscopy suggests the need to consider potential errors. The present study addressed such difficulties and investigated four specific problems: (1) use of exact equations to calculate RBC membrane area and volume; (2) calibration of the pipette internal diameter (PID); (3) correction for a noncylindrical pipette barrel; (4) diffraction distortion of the RBC image. The observed PID represents a cylinder lens enlargement that can be theoretically derived from the glass/buffer refractive index ratio (1.49/1.33 = 1.12). This enlargement was experimentally confirmed by: (1) studying pipettes bent to allow measurement through the barrel (horizontal) and at the orifice (vertical), with a resulting diameter ratio of 1.12 +/- 0.01; (2) and by replacing the surrounding buffer with immersion oil and hence abolishing the lens phenomenon (ratio = 1.12 +/- 0.02). In addition, use of aspirated oil droplets demonstrated a 3.2 +/- 0.2% error when the PID is focused at a sharp, maximum diameter. The average pipette cone angle was 1.49 +/- 0.09 degrees and varied considerably with pipette pulling procedures; calculated tongue geometry inside the pipette was affected by the noncylindrical pipette barrel. The RBC diffraction error, demonstrated by touching two aspirated cells held by opposing pipettes, was 0.091 +/- 0.002 microns. The PID, cone angle, and diffraction artifacts significantly (p < 0.001) affected calculated RBC geometry (average errors up to 5.4% for area and 9.6% for volume). Two new methods to calculate, rather than directly measure, the PID from images of a single RBC, during either osmotic or pressure manipulation, were evaluated; the osmotic method closely predicted the PID, whereas the pressure method markedly underestimated the PID. Our results thus confirm the need to consider the above-mentioned phenomena when determining RBC geometric parameters via micropipette aspiration.

Algorithms

High level expression of functional full length human thyroid hormone receptor beta 1 in insect cells using a recombinant baculovirus.

We have cloned the human thyroid hormone receptor beta 1 (hThR beta) from the human breast cancer cell line T47D using the PCR technique. A recombinant baculovirus transfer vector pVL1392/hThR beta was constructed and the full length receptor was expressed in the insect cell line Spodoptera frugiperda (Sf9). Approx. 10-15 x 10(6) receptors are expressed/cell which implies a production level of 2.5-4.0 mg hThR beta/l of cell culture. The expressed hThR beta displayed a single class of binding sites for T3 with high affinity. Western blot analysis using a polyclonal antibody indicated that the molecular weight of the baculovirus expressed receptor is approx. 50 kDa. Crude nuclear extract of hThR beta labeled with [125I]T3 sedimented as a 4 S peak on a glycerol gradient. No receptor could be detected in the cytoplasm indicating its proper translocation to the nuclear compartment. An oligonucleotide containing a palindromic thyroid hormone response element is specifically recognized and retarded in a gel-mobility-shift assay in the presence of nuclear extract of Sf9 cells expressing hThR beta. These data suggest that hThR beta expressed in Sf9 cells is functional and displays characteristics virtually indistinguishable from those of the thyroid hormone receptor (ThR) extracted from mammalian cells. Furthermore, the data indicate that the baculovirus expression system is adequate for large-scale production of receptor for detailed structural and functional studies.

Animals

Ursodeoxycholic acid-induced changes of plasma and urinary bile acids in patients with primary biliary cirrhosis.

Ursodeoxycholic acid treatment of patients with primary biliary cirrhosis may lead to relief of pruritus and improvement of biochemical liver tests. The changes in serum and urinary bile acids induced by ursodeoxycholic acid treatment were studied. After 29 patients with primary biliary cirrhosis were treated with ursodeoxycholic acid (750 to 1,000 mg/day) for 6 to 12 mo because of an increase in ursodeoxycholic acid, total plasma bile acids increased from 30.5 +/- 6 mumol/L (mean +/- S.E.M.) to 52.7 +/- 11.7 mumol/L (p less than 0.01). The increase in total plasma bile acids correlated significantly with concentrations of plasma bile acid before treatment (p less than 0.01). The concentrations of endogenous bile acids decreased, mainly because of a decrease of cholic acid. During treatment, glycine conjugation increased and taurine conjugation decreased, whereas sulfation and glucuronidation of bile acids were unchanged. In 10 patients with primary biliary cirrhosis in stages III and IV, urinary excretion of bile acids was also studied. After treatment, ursodeoxycholic acid and its 3-beta isomer and C-1-hydroxylated and C-6-hydroxylated derivatives were also excreted. During treatment, urinary excretion of endogenous bile acids decreased. The increase of ursodeoxycholic acid and the decrease of endogenous bile acids may both be related to the improvement of biochemical liver tests in precirrhotic stages of the disease. In cirrhosis, endogenous bile acids in plasma remained high and changes in liver tests were small.

Bile Acids and Salts

Long-term follow-up of posttransfusion and sporadic chronic hepatitis non-A, non-B and frequency of circulating antibodies to hepatitis C virus (HCV).

The natural course of chronic hepatitis non-A, non-B (HNANB) was documented for 3-20 yr (mean 8 yr) in 86 patients, who attended our special ambulance between 1981 and 1988. Sixty five of the 86 patients (75%) were positive for circulating antibodies against hepatitis C virus (HCV) (anti-HCV). Twenty four patients had chronic posttransfusion (PT)-HNANB (18 anti-HCV-positive; 75%), and 62 patients had sporadic (S)-HNANB (47 anti-HCV-positive; 75%). Twenty nine per cent of patients with chronic PT-HNANB had sustained normalization of aminotransferases after a period up to 5 yr, 55% demonstrated chronic persistent hepatitis (CPH) and 16% progressed to chronic active hepatitis (CAH) with transition to cirrhosis. In the group with chronic S-HNANB, 2% of patients showed remission, 43% had stable CPH and 55% progressed to CAH or cirrhosis. However, development of cirrhotic complications required many years. Transition from CAH to CPH or remission was not observed. The results indicate that 75% of both patients groups with chronic PT- and S-HNANB are infected with the same agent, of which antibodies are detected by the new anti-HCV assay. There was no statistical association between the severity of the disease and the presence of anti-HCV. The different proportions of progressive courses in chronic PT- and S-HNANB might be explained by the patient recruitment.

Blood Transfusion

Liver membrane antibodies (LMA) recognize a 26-kD protein on the hepatocellular surface.

Sera from 82 patients with chronic inflammatory liver diseases and from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Hashimoto's thyroiditis were studied by immunoblotting against purified liver plasma membranes (LPM) and soluble liver protein (SLP) fractions from different species after previous separation by SDS-PAGE. Eighteen of 19 sera with LMA of IgG type in immunofluorescence assay and six LMA-negative sera (three sera from patients with RA) showed antibodies of the IgG or IgM classes against a protein with a molecular weight of 26 kD which was present in LPM and SLP fractions from rats, rabbits, pigs and humans. The reaction with 26-kD liver protein did not correlate with other known autoantibody-antigen systems. All sera were negative in the 26-kD region with liver mitochondria, liver microsomes and soluble proteins of kidney (with one exception), heart and gut from the rat. The 26-kD protein was purified by affinity chromatography on immobilized anti-26-kD protein antibodies from patients, eluted from the 26-kD band of immunoblots. Studies with purified 26-kD liver protein and with SLP as antigens after separation in two-dimensional electrophoresis confirmed that patient serum and experimental rabbit antiserum react with the same protein. Eluted patient antibodies and rabbit antisera showed a linear fluorescence pattern on isolated hepatocytes from rat and rabbit. The data indicate that one of the target antigens of LMA is a species-nonspecific 26-kD protein located on the hepatocellular surface.

Adolescent

Guinea pig maximization test with a polyether impression material.

Adverse reactions to a polyether rubber impression material introduced in the mid-sixties have been reported in the literature. Most of the reports are inconclusive regarding the distinction between allergic and toxic responses. The aim of this study was to assess the allergenic potential of this material using a guinea pig maximization test. Ten guinea pigs in the experimental group were sensitized in two steps. First, an extract of the material was injected intradermally, and 7 days later, the material mixed in petrolatum was applied topically. After another 2 wk test solutions were applied, and the skin response was evaluated by visual inspection. Ten nonsensitized animals served as controls. From the challenge test it was evident that the catalyst as well as the freshly mixed material elicited positive skin reactions interpreted as being delayed hypersensitivity reactions. The findings indicate that the material contained substances which could be classified as strong to extreme sensitizers. Some of the adverse reactions seen in connection with the use of this material might well be related to delayed hypersensitivity reactions.

Allergens

Antibody activity against lipopolysaccharides, lipid A and proteins from Enterobacteriaceae in patients with chronic inflammatory liver diseases.

These studies are concerned with detection of circulating antibodies against various defined enterobacterial antigens in patients with chronic inflammatory liver diseases such as chronic hepatitis type B (n = 46), chronic active hepatitis (CAH) of autoimmune type (n = 10), alcoholic cirrhosis (n = 24) and primary biliary cirrhosis (PBC) (n = 24) as well as in healthy individuals (n = 39). Anti-LPS and anti-lipid A were determined by hemolytic and hemagglutination assay. Immunoblot technique was used to investigate the antibody activity against plasmid encoded proteins from Yersinia enterocolitica. Persistent titers of anti-LPS up to serum dilution 1:32.768 were found with hemolytic and hemagglutination assay in patients with alcoholic cirrhosis or PBC and in healthy control. In contrast nearly 50% of patients with chronic hepatitis B had no hemolytic antibodies against the two LPS E. coli serotypes at the time of liver biopsy. Anti-lipid A was detectable in 58% of patients with alcoholic cirrhosis but in low titers in less than 10% in the other groups (p less than 0.001). Alcoholic cirrhosis was also associated with a high frequency of IgG and IgA antibodies against plasmid encoded proteins from Yersinia enterocolitica. The data indicate that the O-polysaccharides as strong antigens are physiologically exposed to the immune system while lipid A and enterobacterial proteins are solely immunogenic under abnormal conditions.

Adult

Experimental liver membrane antibodies (LMA) and antibodies against "liver specific protein (LSP)"--a comparative in vitro study.

Experimental antisera against the 26 kD rat liver protein--recently defined as a target antigen of LMA--and against "LSP" were tested on tissue sections and isolated hepatocytes from rat as well as with a variety of subcellular fractions as antigens. Anti-26 kD protein resulted in sharp immunofluorescence staining of hepatocellular plasma membranes in liver sections and on isolated hepatocytes, while the antiserum did not react with intracellular structures and was also negative with tissue sections from kidney and heart. Anti-"LSP" stained the plasma membranes of isolated hepatocytes, the cytoplasma of liver and kidney sections as well as the connective tissue of heart sections. In Western blot studies anti-26 kD protein showed a single band at 26 kD when liver plasma membranes and soluble liver protein fractions were used as antigens; a weak reaction was observed with microsomes and soluble kidney protein fractions, but there was no reaction with mitochondria or soluble heart proteins. Anti-"LSP" reacted with various proteins of the subcellular fractions between 16 and 116 kD. The 26 kD protein was found in peak II of Sepharose 6B chromatography of soluble liver protein fractions but was absent in the "LSP" fraction (peak I). We conclude that experimental LMA and anti-"LSP" recognize different epitopes of the hepatocellular plasma membrane.

Animals

Glycoproteins of rat liver plasma membranes: their hepatocellular, intestinal and renal expression in rat, rabbit and human.

Expression of six glycoproteins (Mr = 60,000 (gp 60), 80,000 (gp 80), 110,000 (gp 110), 120,000 (gp 120), 140,000 (gp 140), 160,000 (gp 160)) recently purified from rat liver plasma membranes (LPM) were compared in the liver, small intestine and kidney of the rat, rabbit and human. Immunoblotting studies with monospecific antisera showed that five of the six glycoproteins (gp 60, gp 80, gp 110, gp 120, and gp 140) were expressed not only in LPM of the rat but also in LPM from the rabbit and human with Mr corresponding to those of the glycoproteins isolated from the rat. In contrast, the glycoprotein gp 160 was only detected in rat liver. The same pattern of expression was found by immunofluorescence on isolated hepatocytes from the three species. In rat liver, the glycoproteins were localized primarily either in the bile canalicular domain (gp 80, gp 110, gp 120), or in the sinusoidal domain (gp 60, gp 140), or they were distributed over the whole hepatocellular surface (gp 160). In rat, but not in rabbit or human, the glycoproteins gp 110, gp 120 and gp 140 were also found in the small intestine localized either in the brush border membrane (gp 110, gp 120) or over the whole surface membrane of enterocytes (gp 140). Gp 120 was also detected in the luminal pole of tubular epithelial cells of rats kidney. The data show that LPM of different mammalian species share several common glycoprotein antigens. These glycoproteins, that are also partly expressed in extrahepatic tissues, may represent plasma membrane structures conserved among mammalian species.

Animals

[Long-term treatment of cryptogenic hepatitis C using recombinant interferon alpha].

In a pilot study 15 patients with cryptogenic chronic hepatitis non-A, non-B received human recombinant interferon alpha (rIFNa) at a dosage of 5 million units 3 times per week for periods of up to 4 months, followed by an additional 4-month course of treatment with 2 million units 3 times per week after an observed reduction in serum aminotransferase levels. Ten of the 15 patients demonstrated antibodies to hepatitis C virus (HCV). Pretreatment histological examinations revealed evidence of chronic aggressive hepatitis in 12 patients, 4 with signs of cirrhosis, and chronic persistent hepatitis (CPH) in the remaining 3 cases. Normalization of serum aminotransferase levels was documented in 9 patients (7 anti-HCV-positive), and a significant reduction occurred in 2 additional anti-HCV-positive cases. Follow-up biopsy at 8 months in 7 of the 11 responders documented improved histological findings in every case. Five patients with CAH in the initial study had discrete residual portal inflammation or mesenchymal reaction in the second histological examination. Clinical follow-up is currently at 12 month, and 3 anti-HCV-positive responders have normal aminotransferase levels. The data show that a subset of patients with chronic hepatitis C will demonstrate remission of disease after an 8-month course of treatment with rIFNa.

Adult

Relation between Escherichia coli R(rough)-forms in gut, lipid A in liver, and primary biliary cirrhosis.

Since antimitochondrial antibodies (AMA) specific to primary biliary cirrhosis (PBC) recognise enterobacterial proteins and can be induced by R(rough)-mutants of enterobacteriaceae a study was done to find out the prevalence of enterobacterial R-forms in stool samples of patients with chronic inflammatory liver diseases. Liver biopsy specimens were also examined for lipid A, a common antigenic component of the cell wall in gram-negative bacteria. In all stool samples from the 21 patients with PBC Escherichia coli R-forms constituted up to half of the total amount of E coli. In contrast E coli R-forms were detectable in the stools of only 1 healthy control (n = 20), and in 25% of patients with other cholestatic diseases (n = 10), chronic hepatitis type B (n = 15), type non-A, non-B hepatitis (n = 15), or chronic pancreatitis and fat malabsorption (n = 8). An immunoblot technique showed that E coli R-forms isolated from patients' stools contained PBC-specific AMA-reactive proteins with molecular weights of 70-80 kD and 50 kD. Deposits of lipid A, located primarily in the cytoplasm of hepatocytes, were found in 11 patients with PBC but not in the liver of patients with chronic viral hepatitis. Circulating antibodies against lipid A were found rarely and in low titres. The data support the hypothesis that intestinal enterobacterial R-forms are aetiologically important in PBC and that antigens released from the bacterial cell wall contribute to the pathogenesis of the disease.

Adult

HBcAg expressed on the surface of circulating Dane particles in patients with hepatitis B virus infection without evidence of anti-HBc formation.

Circulating immune complexes composed of HBcAg and anti-HBc have been demonstrated recently in patients with hepatitis B virus replication. After dissociation of immune complexes by chaotropic ions, HBcAg was quantified radioimmunologically. In the present study, we describe 10 patients with hepatitis B virus replication, absent or delayed anti-HBc formation and exposed HBcAg in serum. Four of the 10 patients had acute hepatitis, and six patients had chronic persistent hepatitis. In seven of 10 patients, a secondary immune defect was apparent due to acquired immunodeficiency syndrome, leukemia, histiocytosis X, sarcoidosis or end-stage renal disease. Electron microscopy demonstrated that Dane particles from anti-HBc-negative patients were agglutinated after addition of monoclonal anti-HBc antibodies, whereas Dane particles from anti-HBc-positive sera did not show agglutination. Monoclonal HBsAg-specific antibodies aggregated Dane particles independent of the presence of anti-HBc. Circulating HBcAg was always associated with the Dane particle fraction after density gradient separation. Hepatitis B virus core proteins from patients with and without anti-HBc studied by immunoblotting after sodium dodecyl sulfate-gel electrophoresis showed identical patterns. Hepatocytes from anti-HBc-negative patients were positive for HBcAg but negative for immunoglobulin G by immunofluorescence technique. The data indicate that HBcAg may also be expressed on the surface of Dane particles, where it is commonly masked by anti-HBc.

Acute Disease

Maternal weight, weight gain and birthweight at term in the rural Tanzanian village of Ilula.

In an area-based study in a rural Tanzanian village, the relations of maternal weight and weight gain during pregnancy to birthweight were analysed for 331 term deliveries. The distribution of body-mass index, used as an indicator of maternal nutritional status, was similar to the pattern seen in Sweden, although mean maternal height (156 cm) was 9 cm below that of Swedish women. Mean initial weight measured at week 14 was 53 kg and total pregnancy weight gain was 6 kg. Women weighing greater than or equal to 60 kg in early pregnancy gained less weight (0.16 kg/week) than those weighing less than 50 kg (0.22 kg/week). Birthweight was correlated both with maternal weight in early pregnancy and with weight gain during pregnancy, but only 10% of the variation in birthweight was explained by these maternal factors. Mean maternal weight 24 h postpartum was equal to the weight at 14 weeks of pregnancy, implying, on the average, no net weight gain. Women with a positive net weight gain had heavier babies than women with a negative net weight gain. Maternal anthropometric characteristics are important underlying determinants of intrauterine growth and birthweight, but they explain only a minor part of the variation and are of little value for screening purposes in individual women.

Adult

A prospective area-based study of the outcome of pregnancy in rural Tanzania.

A prospective area-based study on the outcome of pregnancy was carried out in the rural village of Ilula in Tanzania. A coverage of 99% (n = 719) regarding the ultimate outcome for mother and child was achieved, including deliveries that took place in hospital (9%), at the dispensary (67%) and at home (23%). There were four maternal deaths (6/1,000). The mean birth weight for singletons was 3,070 g and the low birth weight (less than 2,500 g) rate 13%. From a gestational age of 37 weeks onwards there was a definite slowing of fetal growth. Perinatal mortality rate was 82 per 1,000 born, half of the deaths occurring in low birth weight babies. Twinning occurred in 3.5% and the mean length of gestation at delivery for these pregnancies was 35.5 weeks. Twins constituted 6.8% of newborns but accounted for 23.0% of perinatal losses, making twin pregnancy a major contributor to perinatal mortality. Post-term pregnancies carried no significant increase in mortality. It is concluded that reliable area-based data on the outcome of pregnancy in Tanzania can be obtained at village level, with good coverage of the study population, by properly instructed and motivated local staff with moderate supervisory support.

Delivery, Obstetric

Biochemical analysis of bovine lens sections obtained by a new sectioning device.

One mm thick layers were reproducibly sliced from the punched-out inner cylinder of bovine lenses. The layers were obtained by a special designed freeze-sectioning device. Biochemical analysis of these layers revealed a detailed picture of the lenticular distribution of the amount of water-insoluble and urea-insoluble fractions. Furthermore, the distribution of the content of glucose, fructose and sorbitol was established. The results clearly show the usefulness of a microsectioning device to obtain layers for subsequent biochemical analysis which may lead to a comprehensive understanding of age- and/or cataract-related alterations within one lens.

Aging