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M Berger

Publications and source records attributed to M Berger.

At least 361 records · Page 20Linked to original sources
PubMed1994

Secretory vesicles are the intracellular reservoir of complement receptor 1 in human neutrophils.

The subcellular localization of complement receptor 1 (CR1) was investigated in human neutrophils. CR1 was located exclusively in the light membrane fractions containing secretory vesicles and plasma membranes in Percoll density gradients of unperturbed neutrophils. Separation of plasma membranes from secretory vesicles by high-voltage free-flow electrophoresis of the light membranes from the Percoll gradient revealed that more than 80% of the CR1 was located intracellularly in secretory vesicles. After weak stimulation of neutrophils, the increase in CR1 surface expression closely paralleled both surface increase of known secretory vesicle membrane Ags and the release of matrix proteins from secretory vesicles. More potent stimulation of the neutrophils did not enhance CR1 surface expression further, in agreement with the lack of CR1 in granules as demonstrated on Percoll gradient. CR3 (Mac-1), which has been shown to be located both in secretory vesicles and in neutrophil granules, was up-regulated in parallel with CR1 after weak stimuli, whereas a profound increase of CR3 was observed after more potent stimuli in accordance with granule mobilization. These results identify secretory vesicles as the reservoir of CR1, which translocates to the plasma membrane after weak stimulation, and underscore the functional significance of this recently identified organelle.

Cytoplasmic Granules↗
PubMed1994

In vivo production of human factor VII in mice after intrasplenic implantation of primary fibroblasts transfected by receptor-mediated, adenovirus-augmented gene delivery.

Hemophilia A is caused by defects in the factor VIII gene. This results in life-threatening hemorrhages and severe arthropathies. Today, hemophiliacs are treated with human blood-derived factor VIII. In the future, it may be possible to use gene therapy to avoid long-term complications of conventional therapy and to improve the quality of life. However, initial gene therapy models using retroviral vectors and nonviral gene transfer techniques to introduce factor VIII gene constructs have been hampered by low expression levels of factor VIII. We show here that high expression levels of the B-domain-deleted human factor VIII in primary mouse fibroblasts and myoblasts are obtained by using receptor-mediated, adenovirus-augmented gene delivery (transferrinfection). We demonstrate that, presumably owing to the high molecular weight of factor VIII or its metabolic instability, secretion into the blood and attainment of therapeutic in vivo levels of factor VIII is achieved only if transfected autologous primary fibroblasts or myoblasts are delivered to the liver or spleen, but not if myoblasts are implanted into muscle, a strategy known to be successful for factor IX delivery.

Adenoviridae↗
PubMed1994

Changes of beta-amyloid precursor protein splice patterns in brain cell aggregate cultures.

The splice pattern of beta-amyloid precursor protein (beta-APP) has been studied in a variety of neuronal and glial cells and in brain cell aggregate cultures by the polymerase chain reaction (PCR). The brain-typical pattern, in which beta-APP695 is the dominant form, has been found only in aggregate cultures but not in any of the other cell types including neuronal cell lines. Selective elimination of glial cells from aggregates resulted in increased quantities of beta-APP695, whereas removal of neurons led to a reduction of beta-APP695 and to an elevation of beta-APP751 and beta-APP770. This shift of splice pattern was not observed in cocultures of the neuronal cell line PC 12 with primary astrocytes combined in a variety of cellular ratios. Blood serum, which is an essential component of these cultures, tested on aggregates, did not reduce the amount of beta-APP695 or have any marked effects on splice patterns generally. From these results it is concluded that investigations on brain-typical splicing of beta-APP require primary neurons. Neuronal cell lines may be no suitable model systems. Splicing events favoring production of beta-APP695 may mark an important, very early step of amyloid formation in the brain.

Amyloid beta-Protein Precursor↗
PubMed1994

Malondialdehyde measurement in urine.

Malondialdehyde (MDA) is an end product of lipid peroxidation and is a frequently measured index of these processes. The thiobarbituric acid (TBA) test is commonly used to measured MDA, but its specificity is questionable due to the presence of interfering chromogens. Wade and van Rij described in 1988 a method which removes these chromogens by HPLC. However, the sensitivity and the resolution of this method was not adequate for measurements of MDA in urine. We have improved this method by replacing TBA with diethylthiobarbituric acid (DETBA). The less polar MDA-DETBA complexes were isolated on Bakerbond cartridges and quantified by HPLC without interference. MDA was detectable using a fluorescence or ultraviolet detector at picomole levels. This technique was applied to urine samples obtained from ten burns patients on different days following their hospitalization. Urinary MDA in burns patients was very high and reached 18.6 mumol/mmol creatinine in one patient compared with a mean value of 0.23 mumol/mmol creatinine in healthy controls. Maximum MDA levels were attained on the third day for the majority of patients and remained, on average, much higher than normal even after 20 days. Using this method, picomole quantities of MDA can be easily and specifically detected in urine samples. This method is useful for assessing an oxidative stress.

Burns↗
PubMed1994

T cell subsets involved in lethal graft-versus-host disease directed to immunodominant minor histocompatibility antigens.

T cell responses to multiple minor histocompatibility antigens are governed by the complex phenomenon of immunodominance, as demonstrated clearly in the generation of CTL in the C57BL/6By (B6) anti-BALB.B strain combination. Immunodominance has also been found in lethal graft-versus-host disease (GVHD) responses directed to BALB.B minor histocompatibility antigens, after transplantation of B6 T cells and T cell-depleted bone marrow to irradiated (825 cGy) recipients of either the BALB.B or CXB recombinant inbred strains. However, previous results indicated that the hierarchy of immunodominance in GVHD differed from that predicted from the in vitro CTL studies. Lethal GVHD was observed in BALB.B, CXBE, CXBI, and CXBJ recipients, but not in CXBG and CXBK recipients, the latter 2 strains expressing immunodominant antigens for CTL generation. A major hypothesis to account for these discordant observations is that GVHD reflected the activity of CD4+, but not CD8+, T cell subsets, in contrast to only the in vitro cytolytic potential of CD8+ T cells. Therefore, the current study was undertaken to assess the GVHD potential of both T cell subsets in the B6-->BALB.B, CXBE, CXBI, and CXBJ strain combinations and to analyze the early GVHD responses in the B6-->CXBG and CXBK strains. The results indicate that lethal GVHD responses in the B6-->BALB.B combination can be mediated by either CD4+ T cells or CD4-dependent CD8+ T cells; a similar observation was made with the B6-->CXBI strain combination. Lethal GVHD in the B6-->CXBE strain combination is mediated only by CD4-dependent CD8+ T cells, whereas GVHD in the B6-->CXBJ combination involves either CD4+ T cells alone or CD4-independent CD8+ T cells. In the B6-->CXBG and CXBK recipients, which do not develop lethal GVHD, the early phases of a GVHD response was detected with involvement of both CD4+ and CD8+ T cells. These results indicate that CD8+ T cells are active at some level in all of the strain combinations tested, that CD4+ T cells do not account for the GVHD immunodominant response in the CXBE recipients, and that the failure to obtain extensive clinical disease in the CXBG and CXBK strains is not due to a lack of a graft-versus-host response.

Animals↗
PubMed1994

Deficient total cell content of CR3 (CD11b) in neonatal neutrophils.

Neonatal neutrophils (PMN) show a well-documented defect in chemotaxis that is associated with several abnormalities of PMN structure and function, including deficient surface expression of CR3 (CD11b), a critical adhesion molecule, on chemoattractant-activated PMN. After activation of PMN with additional stimuli including calcium ionophores, we also found deficient surface CR3 (but normal CR1) expression on neonatal PMN suggesting that abnormal signaling mechanisms are not likely to explain the deficient CR3 expression on activated neonatal PMN. Therefore, we hypothesized that deficient surface expression of CR3 on stimulated neonatal neutrophils is caused by a deficiency in total cell content of CR3. We tested this hypothesis using three different methods to compare the total quantity of CR3 in neonatal versus adult PMN. Western blotting of serial twofold dilutions of PMN lysates from five adult and neonatal pairs, using a monoclonal antibody (MoAb) against CR3 (21PM19C), consistently showed diminished CR3 content in neonatal PMN. A sandwich enzyme-linked immunosorbent assay, in which the CR3 heterodimers in PMN lysates were captured by MoAb to the beta-chain, CD18 (R15.7), then detected with a biotinylated MoAb to the alpha-chain, CD11b (anti-Mac-1), showed that neonatal PMN lysates contain about 66% of adult PMN levels of CR3 (P < 0.03; n = 6). PMN fixed with paraformaldehyde and permeabilized with saponin were studied by immunofluorescence flow cytometry to determine total (surface plus intracellular) CR3 content using phycoerythrin-conjugated MoAb to CR3 (anti-Leu15). Mean total cell CR3 content (in relative fluorescence units) was 58 +/- 14 for adult PMN and 27 +/- 6 for neonatal PMN (n = 5; P = 0.013). In each method, total cell content of CR1 was equivalent for neonatal versus adult PMN. We conclude that neonatal PMN are markedly deficient in total cell CR3 content compared with adult PMN. This result provides a primary explanation for deficient CR3 surface expression on activated neonatal PMN that, in turn, may be important in the chemotactic defect of these cells.

Adult↗
PubMed1994

Effect of insulin concentration, subcutaneous fat thickness and skin temperature on subcutaneous insulin absorption in healthy subjects.

Subcutaneous insulin absorption kinetics were assessed in 50 healthy study subjects (21 female, 29 male; age 26 +/- 3 years, BMI 22.5 +/- 1.8 kg/m2; mean +/- SD) during 45 min after periumbilical injection of soluble human U40- or U100-insulin (0.15 IU/kg). Subcutaneous fat thickness was measured by ultrasound, and skin temperature at the injection site was registered. Serum insulin concentrations increased within 30 min from basal values of 37 +/- 15 to 140 +/- 46 pmol/l after U40-insulin and from 36 +/- 10 to 116 +/- 37 pmol/l after U100-insulin (p < 0.001). After 45 min serum insulin concentrations were 164 +/- 43 pmol/l with U40-insulin and 128 +/- 35 pmol/l with U100-insulin (p < 0.001). Decline in blood glucose levels and suppression of C-peptide were comparable. The serum insulin levels reached 30 and 45 min after U40- and U100-insulin injection were positively correlated with skin temperature (p < 0.0008), and negatively correlated with subcutaneous fat thickness (p < 0.009). In conclusion, the lower insulin concentration of U40-insulin, higher skin temperature, and a thinner subcutaneous fat tissue at the injection site are associated with accelerated and enhanced subcutaneous insulin absorption.

Absorption↗
PubMed1994

Comparative dose-related time-action profiles of glibenclamide and a new non-sulphonylurea drug, AG-EE 623 ZW, during euglycaemic clamp in healthy subjects.

Insulin and glucose responses to glibenclamide were studied in comparison to a novel non-sulphonylurea drug (AG) by means of the euglycaemic clamp technique. Nine fasting male subjects were connected to a Biostator and 1.75, 3.5 or 7.0 mg glibenclamide or 1.0, 2.0 or 4.0 mg AG were given and blood glucose concentrations were clamped at 10% below basal values. Glucose infusion rates were registered over 10 h after administration of the tablet. Maximal glucose infusion rates after glibenclamide were 40% higher compared to AG (1.75 vs 1.0 mg, 3.5 vs 2.0 mg, 7.0 vs 4.0 mg, respectively) and were reached after 3-3.5 h for all doses. After glibenclamide, area under the glucose infusion curves and maximal incremental serum insulin responses were higher by 25-40% and by 30% compared to AG when low, medium and high doses of each drug were tested. However, a linear dose relationship was obtained for both drugs when the glucose infusion rate was plotted against the area under the insulin curve. In fact, both drugs were equipotent on a molecular weight basis. The hypoglycaemic index of both drugs (integrated glucose infusion rate divided by integrated insulin release) expressed per mumol of drug revealed a dose-dependent and parallel inverse curvilinear relation to increasing doses. This methodological approach allowed us to quantify and compare the metabolic effects of oral hypoglycaemic agents under standardised experimental conditions.

Administration, Oral↗
PubMed1994

Basic fibroblast growth factor and fibroblast growth factor receptor I are implicated in the growth of human astrocytomas.

Malignant astrocytomas are highly invasive, vascular neoplasms that comprise the majority of nervous system tumors in humans. A strong association has previously been made between malignancy in human astrocytic tumors and increased expression of certain fibroblast growth factor (FGF) family members, including basic and acidic FGF. The influence of endogenous basic FGF on glioblastoma cell growth in vitro was evaluated using basic FGF-specific antisense oligonucleotides. These studies indicated that human glioblastoma cell growth in vitro, can be inhibited by suppressing basic FGF expression. Human astrocytomas also exhibited changes in FGF receptor (FGFR) expression during the course of their progression from a benign to a malignant phenotype. FGFR2 (bek) expression was abundant in normal white matter and in all low grade astrocytomas, but was not observed in glioblastomas. Conversely, FGFR1 (flg) expression was absent or barely detectable in normal white matter, but was significantly elevated in glioblastomas. Glioblastomas also expressed an alternatively spliced form of FGFR1 containing two immunoglobulin-like disulfide loops (FGFR1 beta), whereas normal human adult and fetal brain expressed a form of the receptor containing three immunoglobulin-like disulfide loops (FGFR1 alpha). Intermediate grades of astrocytic tumors exhibited a gradual loss of FGFR2 and a shift in expression from FGFR1 alpha to FGFR1 beta as they progressed from a benign to a malignant phenotype. The underlying cytogenetic changes that contribute to these alterations are not entirely understood, but abnormalities in the p53 tumor suppressor gene may influence expression of bFGF as well as the FGFR. These results suggest that alterations in FGFR signal transduction pathways may play a critical role in the malignant progression of astrocytic tumors.

Astrocytes↗
PubMed1994

Decreased agonist-stimulated Ca2+ response in neutrophils from patients under chronic lithium therapy.

The agonist-stimulated increase in the intracellular concentration of free Ca2+ ([Ca2+]i) was determined in neutrophils from patients under chronic lithium therapy and a control group of age- and sex-matched healthy drug-free subjects. Cells were stimulated with the chemotactic peptide formylmethionylleucylphenylalanin (fMLP) and the Ca2+ concentrations measured with the fluorescent Ca2+ indicator Fura-2. The Ca2+ response to stimulation with fMLP was significantly attenuated in neutrophils from patients chronically treated with lithium. The data suggest that lithium treatment inhibits the inositol phospholipid second messenger generating system in human cells and support the results of earlier inositol phosphate measurements in fMLP-stimulated neutrophils.

Adult↗
PubMed1994

Sleep EEG of patients with obsessive-compulsive disorder.

Twenty-two patients suffering from an obsessive and compulsive disorder (OCD) according to DSM-III-R were investigated by polysomnographic sleep EEG recordings under drug-free conditions and compared to age- and sex-matched healthy controls. Sleep efficiency was significantly lower and wake % SPT was significantly increased in the patient group compared to healthy subjects. Sleep architecture did not differ among the two samples. Especially REM sleep measures, in particular, REM latency did not differ among the groups. No positive correlation was found between sleep variables and rating inventories for obsession and compulsions (Y-BOCS), depression (Hamilton) and anxiety (CAS). A secondary depression did not influence sleep EEG variables. The results of this study contradict the assumption that OCD patients show REM sleep and slow wave sleep abnormalities similar to those shown by patients with primary depression.

Adult↗
PubMed1994

Sleep in depression: the influence of age, gender and diagnostic subtype on baseline sleep and the cholinergic REM induction test with RS 86.

One hundred and eight healthy controls and 178 patients with a major depressive disorder according to DSM-III were investigated in the sleep laboratory after a 7-day drug wash-out period. Subsamples of 36 healthy controls and 56 patients additionally took part in the cholinergic rapid eye movement (REM) sleep induction test with RS 86. Data analysis revealed that age exerted powerful influences on sleep in control subjects and depressed patients. Sleep efficiency and amount of slow wave sleep (SWS) decreased with age, whereas the number of awakenings, early morning awakening, and amounts of wake time and stage 1 increased with age. REM latency was negatively correlated with age only in the group of patients with a major depression. Statistical analysis revealed group differences for almost all parameters of sleep continuity with disturbed indices in the depressed group. Differences in SWS were not detected. REM latency and REM density were altered in depression compared to healthy subjects. Sex differences existed for the amounts of stage 1 and SWS. The cholinergic REM induction test resulted in a significantly more pronounced induction of REM sleep in depressed patients compared with healthy controls, provoking sleep onset REM periods as well in those depressed patients showing baseline REM latencies in the normal range. Depressed patients with or without melancholia (according to DSM-III) did not differ from each other, either concerning baseline sleep or with respect to the results of the cholinergic REM induction test. The results stress the importance of age when comparing sleep patterns of healthy controls with those of depressed patients. Furthermore they underline the usefulness of the cholinergic REM induction test for differentiating depressed patients from healthy controls and support the reciprocal interaction model of nonREM-REM regulation and the cholinergic-aminergic imbalance hypothesis of affective disorders.

Adolescent↗
PubMed1994

Treatment of primary insomnia with trimipramine: an alternative to benzodiazepine hypnotics?

A group of 19 middle aged patients suffering from primary insomnia according to the DSM-III-R were treated in a single-blind study with trimipramine, a sedating antidepressant. A total of 15 patients completed the study protocol and were evaluated. The present pilot study aimed at investigating the sleep-inducing properties of trimipramine, and at clarifying the question of whether short- or long-term rebound insomnia occurs after discontinuation of this drug. At four measurement points, i.e. under baseline conditions, under treatment and 4 and 14 days after drug discontinuation, sleep was recorded with an ambulatory-electroencephalogram (EEG) monitoring device in the patient's home environment. Simultaneously, psychometric tests were applied to measure withdrawal symptoms, subjective sleep quality and well-being during daytime. Trimipramine at a mean dose of 166 +/- 48 mg led to a significant increase in sleep efficiency, total sleep time, and stage 2% sleep-period time (SPT), whereas a significant decrease in wake time and stage 1% SPT was noted. Insomniac patients reported an improvement in subjectively perceived sleep quality following trimipramine. Additionally, an improvement in well-being during the daytime occurred. Negative side effects were limited to dry mouth due to the anticholinergic properties of the drug. Discontinuation of trimipramine did not provoke either short- or long-term rebound insomnia in objective and subjective sleep measurements considering mean values of the whole sample, although a subgroup of patients did display total sleep times below baseline values during short- and long-term withdrawal, but generally without a concomitant worsening of sleep quality according to the sleep questionnaire.

Adult↗
PubMed1994

Effectiveness and cost-benefit analysis of intensive treatment and teaching programmes for type 1 (insulin-dependent) diabetes mellitus in Moscow--blood glucose versus urine glucose self-monitoring.

In a prospective controlled trial the effects of a 5-day in-patient treatment and teaching programme for Type 1 (insulin-dependent) diabetes mellitus on metabolic control and health care costs were studied in Moscow. Two different intervention programmes were compared, one based upon urine glucose self-monitoring (UGSM, n = 61) and one using blood glucose self-monitoring (BGSM, n = 60). Follow-up was 2 years. A control group (n = 60) continued the standard treatment of the Moscow diabetes centre and was followed-up for 1 year. Costs and benefits with respect to hospitalizations and lost productivity (according to average wage) were measured in November 1992 rubles (Rb.), with respect to imported drugs and test strips in 1992 German marks (DM). In the intervention groups there were significant decreases of HbA1 values [UGSM: 12.5% before, 9.4% after 1 year, 9.2% after 2 years (p < 0.0001); BGSM: 12.6% before, 9.3% after 1 year, 9.2% after 2 years (p < 0.0001) compared to no change in the control group (12.2% before, 12.3% after 1 year)], and of the frequency of ketoacidosis. The frequency of severe hypoglycaemia was comparable between the UGSM (10 cases during 2 years), BGSM (10 cases during 2 years), and the control group (8 cases during 1 year).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Cholinergic neurotransmission, REM sleep and depression.

It is known from animal experiments that the regulation of REM and Non-REM sleep is governed by cholinergic and serotonergic/adrenergic neurons in the brain stem. Cholinergic neurons in the gigantocellular field of the tegmentum seem to be responsible for the triggering and maintenance of REM sleep. These findings are of special interest for interpreting abnormalities of REM sleep in depression. Psychiatric sleep research in the last two decades has demonstrated that an early onset of REM sleep and heightened REM density frequently occurs in patients suffering from depression. Extrapolating from animal data on REM sleep regulation, the premature onset of REM sleep in depression may be interpreted as the consequence of a central nervous cholinergic overactivity or muscarinic supersensitivity. In our experimental work we have tested assumptions of the so-called reciprocal interaction model of NonREM and REM sleep by cholinergic/anticholinergic stimulation strategies of sleep in healthy subjects. Furthermore, the impact of cholinergic stimulation on sleep in depression, healthy control subjects and other psychopathological conditions was investigated. These studies demonstrated that the most pronounced REM sleep response to cholinergic stimulation occurred in depression.

Adolescent↗
PubMed1994

Rat microglial interleukin-3.

Interleukin-3 (IL-3, multi-CSF) is a growth factor for a variety of hematopoietic progenitor cells. Recently, microglial cells, the resident macrophages of the central nervous system (CNS) have been shown to proliferate in the presence of IL-3 both in vivo and in culture. Data obtained from cultured astrocytes gave rise to the hypothesis that astrocytes synthesize the microglial growth factor. This is the first report identifying rat microglial cells themselves as a source of IL-3. Culture media conditioned by isolated microglia enhanced microglial proliferation above fresh media controls. IL-3 polypeptide was detected in both conditioned media (CM) and in microglial cells by Western blotting and immunoprecipitation. Furthermore, anti-IL-3 antibodies were able to inhibit microglial proliferation induced by conditioned media. mRNAIL-3 was present in single microglial cells as revealed by in situ hybridization. Total RNA prepared from purified microglia yielded a single PCR amplification product. Identity of the PCR product was confirmed by Southern blot hybridization using a cDNAIL-3 probe and by DNA sequencing. Expression of mRNAIL-3 was observed in both absence and presence of lipopolysaccharide, a bacterial endotoxin, that commonly induces expression of inflammatory cytokines and inhibits microglial proliferation. It is concluded that IL-3 expression in ensuring the recruitment of enhanced numbers of immunocompetent cells at sites of lesion. In the light of weak immune reactions in the brain, it is hypothesized that the expression of a characteristic T cell feature in monocyte-derived microglia may be a partial compensation of T cell functions in brain lesions.

Animals↗