Biomedical subjects

S Werner

Publications and source records attributed to S Werner.

At least 217 records · Page 12Linked to original sources

PubMed1990

Primary structure, in vitro expression and import into mitochondria of a 29/21-kDa subunit of complex I from Neurospora crassa.

A full-length cDNA clone coding for a cytoplasmically-synthesized subunit of complex I from Neurospora crassa (apparent molecular mass of 29 kDa) was isolated. DNA sequencing revealed an open reading frame coding for a protein containing 201 amino acids. A molecular mass of 21323 Da was calculated. The precursor polypeptide was efficiently expressed in vitro and imported into isolated mitochondria. It is synthesized without a cleavable signal sequence and needs a membrane potential in order to bind to the mitochondrial membranes.

Amino Acid Sequence↗

PubMed1990

Cultured Kaposi's sarcoma-derived cells express functional PDGF A-type and B-type receptors.

We have investigated the role of platelet-derived growth factor (PDGF) for the growth of cultured Kaposi's sarcoma (KS)-derived cells. They were found to bind 125I-PDGF-AA and 125I-PDGF-BB in a manner which is consistent with the presence of both PDGF A-type and PDGF B-type receptors. Furthermore, KS cells responded mitogenically to both PDGF homodimers. This shows that KS cells have functional A- and B-type PDGF receptors, suggesting an important role of PDGF for the growth of KS cells in vitro. In addition we found that KS cells produce PDGF-A chain mRNA in response to PDGF stimulation. This suggests that a PDGF-induced autocrine stimulation involving PDGF-AA which could amplify the response to PDGF occurs in these cells.

Binding, Competitive↗

PubMed1990

Short-term effects of early suckling and touch of the nipple on maternal behaviour.

The objective was to evaluate the effects of suckling within 30 min after birth when skin-to-skin body contact for mothers and infants was held constant in both cases (n = 32) and control groups (n = 25). Mother-infant interaction during breast-feeding, infants' time spent in nursery and different aspects of breast-feeding were evaluated. Prolactin and gastrin were measured in maternal serum before and after breast-feeding on day 4 post partum. The aim to evaluate effects of early post delivery suckling failed since only six of the 32 case infants did suck at this time. In spite of this, we found three significant differences among cases and controls. In the case group where all infants had touched or licked the areola and nipple, the mothers left the infants in the nursery for a significantly shorter time and significantly more mothers talked to their infants during the short breast-feeding observation. Median gastrin levels were significantly lower in cases than in controls both before (P less than 0.01) and after (P less than 0.03) breast-feeding. In conclusion, the infant's early touch of the mother's areola and nipple seemed to have positively influenced the mother/infant relationship during the first four days after birth. It was also associated with lower maternal gastrin levels which suggests that maternal neuroendocrine functions were also influenced. Ten months after birth, we found no differences between cases and controls.

Adolescent↗

PubMed1990

Measurement of progressive cerebral ventriculomegaly in infants after grades III and IV intraventricular hemorrhages.

To develop guidelines that might help predict prospectively which infants with severe intraventricular hemorrhage (IVH) would require intervention, we obtained serial cranial sonograms to measure the rate of growth of cerebral ventricular volumes in 48 preterm infants with and without IVH. The infants were divided into three groups: (1) those with no IVH (22 infants), (2) those with IVH with acute ventricular dilation (13 infants), and (3) those with IVH with progressive ventricular dilation requiring intervention (13 infants). The decision to intervene because of progressive ventricular dilation was based on clinical criteria and the subjective assessment of increasing ventricular size on weekly cranial sonograms. The rate of cerebral ventricular volume growth in infants with IVH who needed intervention was greater (4.2 +/- 3.3 ml/day) than that in infants without IVH (0.0 +/- 0.1 ml/day; p less than 0.001) and in infants with IVH and acute ventricular dilation (0.0 +/- 0.2 ml/day; p less than 0.001). Using these data, we generated guidelines for predicting prospectively which infants with IVH and ventricular dilation will need intervention for posthemorrhagic hydrocephalus. The guidelines were then confirmed prospectively in 10 infants.

Cerebral Hemorrhage↗

PubMed1990

Localization of the MEN1 gene to a small region within chromosome 11q13 by deletion mapping in tumors.

The gene for multiple endocrine neoplasia type 1 (MEN1), an inherited predisposition to neuroendocrine neoplasm of the parathyroid glands, the pancreatic islet parenchyma, and the anterior pituitary gland, was recently mapped to chromosome 11q13 based on genetic linkage in families. We now show that the pathogenesis of MEN1-associated parathyroid lesions involves unmasking of a recessive mutation at the disease locus and that sporadic primary hyperparathyroidism shares the same mechanisms. By examination of allele losses in MEN1-associated lesions, we could define deletions of chromosome 11 and map the MEN1 locus to a small region within chromosome band 11q13, telomeric to the PYGM locus. In contrast, a low incidence of deletions involving the MEN1 gene was found in sporadic pituitary adenomas.

Adenoma↗

PubMed1990

Invasive migration of epidemic Kaposi's sarcoma cells in vitro.

Kaposi's sarcoma (KS) is a low grade malignant neoplasm which shows invasive growth and often occurs in immunosuppressed patients with the Acquired Immune Deficiency Syndrome (AIDS; epidemic KS). It is also found in elderly men where it is usually limited to the skin (classic KS). The present study investigated the chemotaxis and invasive migration of epidemic KS cells in vitro and compared them to cells grown from classic KS lesions and to fibroblasts. Epidemic KS cells demonstrated invasive migration through reconstituted basement membrane (Matrigel) as well as through interstitial connective tissue (collagen I) in early passages, whereas fibroblasts did not invade either barrier. Epidemic KS cells in late passages did not show any invasive migration. Following pretreatment with tumour necrosis factor alpha (TNF-alpha) there was no enhanced migration through the Matrigel and collagen I for epidemic KS cells, whereas classic KS cells showed an increased migration through the type I collagen barrier.

Basement Membrane↗

PubMed1990

The growth hormone, prolactin and TSH response to TRH and L-dopa in patients with hyperprolactinaemia and a normal-sized sella turcica may denote a pituitary adenoma.

Forty-one patients with hyperprolactinaemia and suspected prolactinomas were studied. Growth hormone (GH) and thyrotropin (TSH) secretory patterns after thyrotropin releasing hormone (TRH) were affected in the majority of patients. The disturbances were observed regardless of tumour size as indicated by the radiological sella size. In patients with hyperprolactinaemia and normal-sized sella turcica, an abnormal GH and TSH response to TRH can be helpful in the diagnosis of a microadenoma. The hyperprolactinaemia per se and its effect on dopaminergic hypothalamic neurones may be the cause of the GH and TSH response. By contrast, many patients with macroprolactinomas showed insufficient GH secretory capacity.

Adult↗

PubMed1990

Short term treatment of acromegaly with the somatostatin analog octreotide: the first double-blind randomized placebo-controlled study on its effects.

Several studies suggest that the somatostatin analog octreotide, or SMS 201-995, may effectively reduce GH hypersecretion. However, no double blind, placebo-controlled study has substantiated these findings. We present the results of a randomized double blind 14-day clinical trial with octreotide in 20 patients with acromegaly. The drug was given sc every 8 h and to the initial dose (50 micrograms) was added another 50 micrograms every other day up to 200 micrograms. GH levels, calculated as the mean values of 12 observations at hourly intervals during 0700-1800 h, and insulin-like growth factor-I (IGF-I) levels were significantly reduced during octreotide treatment. Responses varied from a reduction of 97% of the basal mean GH level to no significant reduction in 2 of 10 patients. There was a good correlation between the reduction of GH and IGF-I levels. The main side-effects were gastrointestinal and well tolerated. We found a spontaneous variation of daily mean GH and IGF-I levels (at 0700 h) in the placebo group, ranging from approximately 150% to 50% of the GH and 120% to 80% of the IGF-I levels noted on day 0. In patients treated with octreotide, the occurrence of GH rises between administration times suggests that it may be desirable to give octreotide every 6 h in some patients.

Acromegaly↗

PubMed1990

Characterization of dimeric forms of human pituitary growth hormone by bioassay, radioreceptor assay, and radioimmunoassay.

Seven highly purified dimeric forms of human pituitary growth hormone, composed of the monomeric forms 20 K hGH, 22 K hGH and 24 K hGH linked together by noncovalent or covalent bonds, have been characterized by an in vitro bioassay (the Nb2 assay), a radioreceptor assay and a radioimmunoassay. Considerable differences in the ability to displace labelled recombinant hGH were observed in the radioreceptor assay. The seven dimeric forms varied over a range between 22 K hGH (most effective) and 20 K hGH. The three covalently-linked dimeric forms had nearly identical affinity constants. The mitogenic action of all but one of the hGH dimers in the Nb2 assay was in the same mutual order as the receptor binding activity in the radioreceptor assay. In the RIA, all dose-response curves were parallel except for those obtained with 20 K hGH and with the dimeric form (20 K-20 K)hGH. In this assay, dimeric variants of the constituents 22 K hGH and 24 K hGH were approximately twice as active as 22 K hGH on a molar basis, suggesting about the same affinity between the antibodies and each of the monomeric forms. Determination of the amino acid compositions of the dimeric forms provided support for their content of monomeric constituents as established earlier by electrophoretic analysis.

Amino Acids↗

PubMed1990

Steroid profile in urine: a useful tool in the diagnosis and follow up of adrenocortical carcinoma.

The urinary steroid profile was determined in 24 patients with adrenocortical carcinoma. Seventeen of the patients had Cushing's syndrome, virilization or feminization, and 7 had no signs of endocrine disease. Seven of the 11 patients still alive are free of disease, after a follow-up period of 5-75 months. The steroid profile varied widely between the patients with adrenocortical carcinoma. Patients with Cushing's syndrome had increased levels of cortisol metabolites and those with virilism had raised excretion of androgen metabolites. Six of the patients with adrenocortical carcinoma showed normal values of these metabolites. In 23 of the 24 patients the excretion of 3 beta-hydroxy-5-ene steroids and/or metabolites of cortisol precursors, such as tetrahydro-11-deoxycortisol, were significantly increased, compared with healthy controls or patients with adrenal adenomas. These findings suggest a relative deficit or low activity of 3 beta-hydroxysteroid dehydrogenase/delta isomerase and/or 11 beta-hydroxylase in tumour tissue. In the single patient where the steroid profile failed to indicate malignancy, hypercortisolism was seen and the tumour mass was small. The steroid excretion normalized after radical surgery and decreased in patients responding to chemotherapy. During recurred disease the metabolites of 3 beta-hydroxy-5-ene steroids and/or cortisol precursors increased, but in some patients the excretory pattern then was different from that seen before treatment.

Adrenal Cortex Neoplasms↗

PubMed1990

Monoclonal antibodies reveal circulating growth hormone of high molecular weight not detectable by conventional assays.

A radioimmunoassay based on a monoclonal antibody. Mc-ab 1, which was raised against growth hormone but cross-reacted with human placental lactogen yielded higher GH immunoreactivity levels in serum than one based on a polyclonal antiserum. This discrepancy was noted in subjects with normal GH secretion as well as in patients with GH insufficiency. To characterize this GH immunoreactivity detected by Mc-ab 1, affinity purification and molecular sieve chromatography of serum were performed. High molecular weight proteins with GH immunoreactivity were found with both techniques. These proteins were associated with carbohydrates. Affinity cross-linking showed specific binding of radiolabelled GH to high molecular weight proteins in the serum. After fractionation of serum, the GH immunoreactivity became detectable by the polyclonal antiserum assay as well as by an immunoradiometric assay. GH immunoreactive material with an approximate mass of 80 kD was subjected to isoelectric focusing. When GH immunoreactive fractions at pH 5 were re-chromatographed, GH immunoreactivity was recovered in the elution volume corresponding to monomeric GH. Our results show that sera from normal subjects as well as from patients with deficient GH secretion contain notable amounts of high molecular weight GH which is undetectable by antibodies generally used for GH measurements, but which can be revealed after fractionation of serum.

Acromegaly↗

PubMed1990

Oxytocin and prolactin levels in breast-feeding women. Correlation with milk yield and duration of breast-feeding.

The aim of the present study was to examine suckling-related plasma levels of oxytocin and prolactin in early and established lactation and to correlate hormone profiles to success of lactation performance. Fifty-five primiparous women participated in the study. From each, 18 blood samples were drawn in connection with breast-feeding on day 4 post partum and after 3-4 months. Oxytocin and prolactin levels were determined with radio-immunoassay. Basal levels of both hormones were significantly higher 4 days post partum than 3-4 months later and after weaning. Basal prolactin levels fell significantly within 24 h of weaning. Oxytocin and prolactin levels rose in response to breast-feeding--an effect which persisted during the lactation period. The suckling-induced release of prolactin--but not that of oxytocin--was related to basal hormone levels. Basal as well as stimulated oxytocin levels obtained 4 days and 3-4 months post partum correlated significantly, indicating that each woman has an individual, characteristic level of this hormone. Milk yield did not correlate with oxytocin or prolactin levels, but prolactin levels recorded 3-4 months post partum did correlate with the remaining period of breast-feeding. In addition, mothers who breast-fed exclusively 3-4 months post partum had significantly higher oxytocin and prolactin levels than those who gave supplementary feed. There was a significant correlation between oxytocin levels at 4 days and birth weight of the infant.

Adult↗

PubMed1990

[Studies on the oral health status of elderly and old people in a rural district].

There is reported on an epidemiological study to estimate the gerostomatological treatment need by examining in a rural district all people older than 55 years. The studies were carried out in compliance with the WHO-Basic Methods for oral health services. The results demonstrate that the oral health status of the old people is determined by loss of teeth and its functional consequences. Caries, diseases of the oral mucosa and TMJ-disorders are unimportant in the epidemiological point of view. The condition of porsthetic treatment is quantitative satisfactory in the age-groups up to 75 years.

Aged↗

PubMed1989

Cells derived from sporadic and AIDS-related Kaposi's sarcoma reveal identical cytochemical and molecular properties in vitro.

We have established 40 cell cultures from biopsies of 5 patients with sporadic Kaposi's sarcoma (KS) and compared them with cell cultures derived from KS biopsies of AIDS patients. Immunocytochemical staining of sporadic KS cells revealed the same endothelial cell markers as those expressed on AIDS-KS cells, indicating that both types of KS might be of endothelial cell origin. In contrast to clinical features, in vitro growth properties showed no differences. KS cells of both types reveal a low degree of malignancy but can be distinguished from fibroblasts by a higher passage number in low serum concentrations and a more pronounced dependence on platelet-derived growth factor (PDGF). The DNA of 12 cell lines of both types of KS was negative for genomic equivalents of hepatitis B virus (HBV), cytomegalovirus (CMV) and, in the case of AIDS-KS, for human immunodeficiency virus (HIV). No rearrangements or amplifications of several oncogenes, often involved in human tumors, were detected. The expression of these oncogenes by sporadic and AIDS-KS cells, as analyzed by Northern blotting, was comparable to that of normal dermal fibroblasts from the same patients. Our results indicate that the 2 types of Kaposi's sarcoma possess identical cytochemical and molecular properties. They are probably weakly malignant neoplasms of endothelial cell origin, and paracrine growth stimulation appears to be important for their maintenance and progression.

Acquired Immunodeficiency Syndrome↗

PubMed1989

Photoaffinity labelling of mitochondrial NADH: ubiquinone reductase with pethidine analogues.

1. Chemically reactive derivatives of pethidine analogues--novel potent inhibitors of the mitochondrial NADH: ubiquinone reductase (complex I)--were synthesized. 2. Dose-response curves of these components revealed that the photoactivatable aryl azido derivative has retained most of the inhibitory activity displayed by the parent substance. After introduction of a radioactive iodine isotope into the molecule, it was used as a probe for the localization of the inhibitor binding polypeptides within complex I. 3. Photolysis of the radiolabelled derivative bound to isolated complex I both from Neurospora crassa and beef heart resulted in a covalent incorporation of the inhibitor into 6-7 individual subunits of the enzyme. Essentially the same labelling patterns were obtained, when whole mitochondrial membranes were incubated with the reactive derivative. 4. Applying a double isotope labelling technique, the inhibitor-binding polypeptides in N. crassa were identified as mitochondrially synthesized constituents of complex I (ND gene products). In the beef heart enzyme the ND-1 product was detected to be among the polypeptides reacting with the inhibitor. 5. Competition experiments employing either NADH or decylbenzoquinone (DB), together with the pethidine analogue, showed that both enzyme substrates interfere specifically with the inhibitor binding to complex I.

Affinity Labels↗

PubMed1989

Assembly kinetics and identification of precursor proteins of complex I from Neurospora crassa.

Complex I from Neurospora crassa was fractionated using chaotropic agents and various chromatographic techniques. Several subunits were isolated. Polyclonal antibodies directed against the holocomplex or individual subunits were raised in rabbits, and employed to analyse the composition and assembly of this respiratory chain enzyme in vivo. N. crassa cells were pulse-labelled with radioactive amino acids. The time course of incorporation of radioactivity into complex-I polypeptides was studied by immunoprecipitation. The labelling kinetics of whole complex I was found to be similar to that of cytochrome oxidase, displaying a half-maximal labelling time of 10 min. Newly synthesized individual polypeptide subunits (about 23 species) assembled into the holoenzyme at markedly different rates. Two mitochondrially synthesized proteins, a 29-kDa polypeptide (the ND-1 gene product) and a 12-kDa polypeptide were the fastest components to appear in the enzyme. We estimate that the precursor pool sizes of all components range between 1-25% of the amounts present in the final complex. Precursors of polypeptides of complex I were synthesized in an heterologous cell-free system and immunoprecipitated with subunit specific antibodies. Six isolated precursors were compared with the corresponding mature proteins. It appears that four subunits (apparent molecular masses of 22, 25, 31 and 33 kDa) are initially synthesized as larger-molecular-mass precursors. Two subunits (apparent molecular masses of 12.5 and 14 kDa) are made with the same size as their mature forms.

Enzyme Precursors↗

PubMed1989

Cytochemical and molecular properties of simian virus 40 transformed Kaposi's sarcoma-derived cells: evidence for the secretion of a member of the fibroblast growth factor family.

Contact-inhibited Kaposi's sarcoma-derived cells (KS cells) were transfected with Simian Virus 40 (SV40) DNA. Transformed cells (SV-KSC) were selected for their capacity to form foci on monolayers of the low-malignant KS cells. Isolated SV-KSC foci were found to contain integrated SV40 DNA sequences and to express SV40 large T-antigen. Several differentiation properties of KS cells are retained in the SV40 transformants, e.g., expression of vimentin and the endothelial cell marker BMA 120. In contrast to the maternal KS cells, SV-KSC are capable of growing in platelet-derived growth factor (PDGF)-depleted platelet-poor-plasma serum (PPPS) and in soft agar. However, they are not tumorigenic in nude mice. Expression of the oncogenes c-myc, c-N-ras, c-Ha-ras, and p53 is significantly elevated in SV-KSC, whereas c-fos and c-erb B expression is comparable to that of KS cells and fibroblasts. Conditioned medium from SV-KSC can substitute for PDGF when PDGF-dependent, nontransformed KS cells are grown in PPPS. Biochemical analysis of the SV-KSC supernatant and PDGF A and B mRNA expression analysis provide evidence that the mitogenic activity is not due to a PDGF-like growth factor. On the other hand, there is evidence to indicate that the SV-KSC mitogen is a member of the fibroblast growth factor family. SV-KSC represent an interesting model system for the study of different degrees of malignancy of cultured mesenchymal cells and especially provide an important source for the isolation of a potent growth factor for KS cells and other mesenchymal cells in vitro.

Cell Line, Transformed↗

PubMed1989

Acute antidepressant effect of lithium is associated with fluctuation of calcium and magnesium in plasma. A double-blind study on the antidepressant effect of lithium and clomipramine.

In a double-blind study on 22 patients with major depressive disorder the effects of lithium and clomipramine on signs and symptoms and on calcium and magnesium in plasma were compared. Ratings of antidepressant and side effects were performed by 2 psychiatrists at the end of a placebo period of 5-7 days and after treatment for 2 and 4 weeks. Psychopathology was rated by 15 reported and 4 observed items from the Comprehensive Psychopathological Rating Scale (CPRS). Eleven items present in 72-100% of the patients were used to evaluate the effect of the two drugs. After 2 weeks of treatment the rated scores dropped for more than half of the CPRS items. After 4 weeks the scores for all but one item were reduced in both groups. The sums of scores were significantly reduced after 2 weeks in both groups and after 4 weeks global scores were reduced as well. The drugs had notable and similar antidepressant effects. Lithium treatment was associated with fluctuations in calcium and magnesium levels in plasma not seen during clomipramine treatment. Serum prolactin increased during clomipramine treatment but was unaffected by lithium treatment. No correlations were found between the sum of rating scores and blood levels of drugs, prolactin, calcium or magnesium.

Adult↗