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Biomedical subjects

W Becker

Publications and source records attributed to W Becker.

At least 109 records · Page 6Linked to original sources
PubMed1995

Comparative assessment of saccadic eye movements, psychomotor and cognitive performance in schizophrenics, their first-degree relatives and control subjects.

This study is aimed at detecting biological markers for schizophrenia. For this purpose, a total of 70 subjects (21 schizophrenic patients, 27 first-degree relatives and 22 controls) performed a series of tests assessing various attentional, psychomotor and cognitive functions and saccadic eye movements. The schizophrenics performed significantly poorer than both high-risk and control subjects in most of the tests demanding attention, concentration and psychomotor speed (d2 concentration test, reaction times and Stroop test of perceptual interference) as well as cognition (Wechsler intelligence scales). On the other hand, these tests did not differentiate between the high-risk and control subjects. This distinction, however, could be made by two other parameters: hypometria score of saccadic eye movements and ratio of verbal to performance intelligence scores. Both parameters were significantly increased in both the schizophrenic and the high-risk group, distinguishing both from the control group. The relevance of these findings in indicating a schizophrenic disposition is discussed.

Adult↗
PubMed1995

Uptake and interconversion of plasma unesterified n-3 polyunsaturated fatty acids by the GI tract of rats.

The origin of the linoleic [18:2(n-6)], arachidonic [20:4(n-6)], and docosahexaenoic acid [22:6(n-3)] of the mucosal phospholipids in the gastrointestinal (GI) tract is not known. This study examines whether stomach, small intestine, and colon take up and desaturate-elongate unesterified polyunsaturated fatty acids (PUFA) from blood. Albumin-bound unesterified alpha-[14C]linolenate [18:3(n-3)] and [3H]eicosapentaenoate [20:5(n-3)] were injected intravenously. After 10 min, 1 h, and 18 h, radioactivity of tissue lipids and the degree of interconversion of the 3H-labeled and 14C-labeled fatty acids were determined. After 10 min, the lipids of the gastrointestinal tract contained 3.6% of the 14C (0.5% in stomach, 2.7% in small intestine, and 0.4% in colon) and 4.9% of the 3H (0.6% in stomach, 3.6% in small intestine, and 0.7% in colon). Both fatty acids were acylated mainly into phospholipids, both in liver and gastrointestinal tract. Although the proportions of radioactivity found in desaturation-elongation products increased with time, 15% of the 14C in the liver, 6% in the stomach, 8% in the small intestine, and 11% in the colon were in 20:5 already after 10 min. A rapid interconversion of 18:3 thus occurred both in the liver and in the gastrointestinal tract. In all tissues examined, interconversion of [3H]20:5 to [3H]22:5 also occurred. Interconversion of unesterified PUFA taken up from blood may be an important source of eicosanoid precursors in the gastrointestinal tract.

Animals↗
PubMed1995

Human demineralized freeze-dried bone: inadequate induced bone formation in athymic mice. A preliminary report.

The purpose of this study was to test the osteoinductive properties of demineralized freeze-dried bone (DFDBA) randomly purchased from four commercial bone banks. Twenty-five (25) milligrams of bone from each of the banks was implanted into the hindquarter muscles of athymic mice. Two samples from each of the banks were compared with samples from the other banks. A total of 16 implants were grafted into 8 mice. Two additional mice served as controls. One mouse received an implantation of deactived human cortical bone matrix (DBM) (negative control). The other mouse received an implant of human bone morphogenetic protein/non-collagenous proteins (hBMP/NCP) infused to surface demineralized human cortical bone (positive control). At 21 days the mice were killed, the hindquarters were photographed, and the tissues were prepared for histologic evaluation. Of the 16 commercial DFDBA implants, 12 were available for histologic evaluation. There was no radiographic evidence of bone formation for the DFDBA implanted mice or the DBM implants. Small bone ossicles were scarcely visible in the hindquarters of the mouse which received the hBMP/NCP infused bone. Histomorphometric analysis was used to determine the percentage of new and dead bone. The bone was measured in pixels. The predominant histologic feature of the DFDBA implants was non-vital bone chips with minimal amounts of new bone. The average amount of non-vital bone ranged from 78.4% to 92.5%. There was no evidence of bone formation for the DBM implants. The average amount of bone for the mouse which received hBMP/NCP was 96%. The results of this pilot study indicate that commercially-available DFDBA induced clinically insignificant amounts of bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Eye stabilization by vestibulo-ocular reflex (VOR) and optokinetic reflex (OKR) in macaque monkey: which helps which?

VOR-OKR interaction was studied in macaque monkey in the frequency domain, using various vestibular-visual stimulus combinations in the horizontal plane. At low stimulus frequencies (< 0.1 Hz), the eyes were always stabilized on the optokinetic pattern, irrespective of whether the head, the pattern, or both were rotated. At higher frequencies, the gain of the OKR attenuated, and concomitantly the eyes became increasingly stabilized in space. These findings show that the VOR becomes functionally relevant only at high frequencies. It compensates for the limited bandwidth of the OKR, thereby improving vision provided the pattern to be fixated is stationary in space.

Animals↗
PubMed1995

Prolactin-producing pituitary tumor: resistance to dopamine agonist therapy. Case report.

A 14-year-old girl presented with a rapidly growing, invasive prolactin-producing pituitary tumor that failed to respond to dopamine agonist medication. Histological, immunocytochemical, and ultrastructural studies of the surgically removed tissue revealed a pleomorphic, chromophobic, or slightly acidophilic pituitary tumor that was immunoreactive for prolactin and that, according to electron microscopy, consisted of atypical lactotrophs showing no evidence of cell shrinkage. In situ hybridization demonstrated large amounts of prolactin messenger ribonucleic acid (mRNA), moderate amounts of estrogen receptor mRNA and dopamine (D2) receptor mRNA, and an absence of growth hormone mRNA in the tumor cells. Because D2 receptor mRNA was present in the tumor, causes other than D2 receptor loss may have been responsible for the resistance of the lactotrophs to dopamine agonist administration.

Adenoma↗
PubMed1995

Somatostatin receptor expression in the thyroid demonstrated with 111In-octreotide scintigraphy.

Neuroendocrine tumors with somatostatin receptor expression may be localized by 111In-octreotide scintigraphy. This study examines those thyroid conditions where 111In-octreotide uptake could be observed also in the thyroid gland. 26 consecutive patients who underwent 111In-octreotide scintigraphy for tumor localization were additionally examined for thyroid disease by sonography and 99mTc-pertechnetate scintigraphy. 12 of these patients had no significant thyroid uptake and had an euthyroid normal-sized thyroid gland 14 patients with 111In thyroid uptakes had endemic goiters, two of them with thyroid autonomy and one with Graves' disease. Thus, 111In-octreotide thyroid uptake was predominantly seen in patients with endemic goiter with or without thyroid autonomy.

Adult↗
PubMed1995

[Complete nutrition and social assistance].

Additional supplementary benefits for nutrition are provided by social legislation; they are based on recommendations which have to be reconsidered in general as regards contents and quantities. The practice of assessment by Public Health Offices has no standardized regulations. Surveys have indicated that the recommendations are based on low-price calculations. The fundamental basis of supplementary benefits cannot guarantee healthy nutrition and therefore ignores the aim of prevention which had originally been included in social legislation.

Cost-Benefit Analysis↗
PubMed1995

Rat adjuvant arthritis: imaging with technetium-99m-anti-CD4 Fab' fragments.

UNLABELLED: The abundance of CD4 molecules on inflammatory cells in the synovial membrane renders anti-CD4 monoclonal antibodies (MAbs) or their fragments very promising for specific imaging of arthritic joints. METHODS: Joint uptake and body distribution of a 99mTc-labeled Fab', derived from the anti-rat CD4 MAb W3/25 (IgG1), were investigated following intravenous injection in normal and adjuvant arthritic rats. An isotype-matched Fab' (anti-human nonspecific crossreacting antigen-90) was used as control. RESULTS: A 14-hr sequential pinhole scan of the ankle joints revealed that both the anti-CD4 and the control Fab' accumulated to a higher degree in arthritic than in normal ankle joints; however, accumulation of the anti-CD4 Fab' in arthritic joints exceeded that of the control Fab' (approximate to 1.6 fold). Preferential joint accumulation of anti-CD4 Fab' was confirmed by whole-body scans at 14 hr and by direct well counter measurements of tissue samples at 16 hr following injection. Unlike the control Fab', the anti-CD4 Fab' preferentially accumulated in the liver and lymph nodes, organs rich in CD4-positive cells, as observed by direct tissue measurements. CONCLUSION: Despite its monovalency, the anti-CD4 Fab' retains the in vivo selectivity for CD4-positive cell-rich tissues, previously reported for the complete anti-CD4 MAb, and improves imaging of inflamed joints in experimental adjuvant arthritis.

Animals↗
PubMed1995

99mTc-trimethyl-BrIDA scintigraphy in HIV-related cholangiopathy.

A HIV-infected 37-year-old man with diffuse mid-abdominal pain and elevated liver enzymes was sequentially studied by sonography, computed tomography (CT), 99mTc-trimethyl-BrIDA scintigraphy and endoscopic retrograde cholangiopancreatography (ERCP). CT and sonography did not lead to a final diagnosis. Cholescintigraphy showed signs of cholecystitis and sclerosing cholangitis with intra- and extrahepatic bile duct dilatation. These findings could be confirmed by ERCP, rendering HIV-associated cholepathy probable. Cytomegalovirus infection was demonstrated by polymerase chain reaction from bile fluid and the presence of cryptosporidia infection in a histology specimen isolated by ERCP. Therefore, biliary scintigraphy seems promising for screening for HIV-associated cholangio- and cholecystopathy, being less invasive and less bothering for the patient than ERCP.

Adult↗
PubMed1994

[Neonatal hyperthyroidism in non-diagnosed Basedow's disease of the mother. Problems of diagnosis and therapy illustrated by a case history].

A male preterm infant (born at 34 weeks, birth weight 2130 g) developed jaundice (total bilirubin 7.4 mg/dl), hepatosplenomegaly, thrombocytopenia (82,000/microliters) and a raised C-reactive protein (1.2 mg/dl). Although sepsis was suspected, no organism was demonstrated. When the mother visited the child for the first time after 2 weeks, she had florid hyperthyroidism. This explained many of the child's clinical features (poor weight gain, tachycardia, exophthalmos). Both mother and child had raised TSH receptor antibodies (mother: 684.6 U/l; 54.1 U/l, normal < 15 U/l), an increased free T4 and a suppressed TSH. Because of the tachycardia, the child was treated with propranolol (1 mg/kg.d for 5 weeks). He was also initially given Lugol's solution (25 mg iodide/kg.d for 1 week) and then propylthiouracil (7 mg/kg.d) because of the increasing total T3. L-Thyroxine replacement was subsequently required for a period of 2.5 weeks because of treatment-related hypothyroidism. Since stopping treatment (at 12 weeks of age), the child has developed normally.--Neonatal hyperthyroidism due to transplacental transfer of TSH receptor antibodies associated with maternal Graves' disease is a rare self-limiting condition. However, it may pose considerable danger to the child both in utero and postnatally (with a mortality if untreated of up to 20%). Interdisciplinary cooperation is essential.

Adult↗
PubMed1994

Molecular cloning of a protein serine/threonine phosphatase containing a putative regulatory tetratricopeptide repeat domain.

Two novel protein serine/threonine phosphatases were cloned from a rat fat cell library with probes generated by a polymerase chain reaction-based cloning approach. One of these cDNAs encoded a protein presumably representing the rat homologue of PPV from Drosophila (75% identity of amino acids). The other novel cDNA encoded a protein phosphatase of 499 amino acids and was designated PPT. Its catalytic domain contains motifs typical for protein phosphatases but is only distantly related with PP1, PP2A, and PP2B (38-42% identical amino acids). When expressed in Escherichia coli, the catalytic domain of PPT exhibited protein phosphatase activity (dephosphorylation of phosphorylase a) that was inhibitable by okadaic acid. As a unique feature among other members of this gene family, PPT has an amino-terminal extension of 200 amino acids harboring three tandemly arranged tetratricopeptide repeat (TPR) motifs. This domain has previously been found in other proteins involved in the regulation of RNA synthesis or mitosis. mRNA of PPT was predominantly found in brain and, in lower levels, in testis, but was nearly undetectable in spleen, lung, skeletal muscle, kidney, and liver. It is suggested that the TPR domain of PPT may be involved in the regulation of the function of this novel protein phosphatase.

3T3 Cells↗
PubMed1994

JIP60, a methyl jasmonate-induced ribosome-inactivating protein involved in plant stress reactions.

Plant tissues treated with the naturally occurring cyclopentanone compound methyl jasmonate or exposed to stress causing in planta jasmonate accumulation express distinctive proteins and, concomitantly, reduce the synthesis of most preexisting proteins. One of the recently identified jasmonate-induced proteins, designated JIP60, in barley is a ribosome-inactivating protein that cleaves polysomes of both animal and plant origin into their ribosomal subunits. By attacking foreign and self ribosomes, respectively, JIP60 appears to be both a defense protein and a potent regulator of protein synthesis in stressed plant tissues.

Acetates↗
PubMed1994

Substitution of conserved tyrosine residues in helix 4 (Y143) and 7 (Y293) affects the activity, but not IAPS-forskolin binding, of the glucose transporter GLUT4.

Six tyrosine residues (Y28, Y143, Y292, Y293, Y308, Y432(1)) which are conserved in all mammalian glucose transporters were substituted for phenylalanine by site-directed mutagenesis, and mutant glucose transporters were transiently expressed in COS-7 cells. Glucose transport activity as assessed by reconstitution of the solubilized transporters into lecithin liposomes was reduced by 70% in the mutant Y143F and appeared to be abolished in Y293F, but was not affected by substitution of Y28, Y292, Y308 and Y432. In contrast, covalent binding of the photolabel 125IAPS-forskolin was normal in all mutants. Stable expression of the mutants Y143F, Y293F, and Y292F in LTK cells yielded identical results. These data indicate that only two of the 6 conserved helical tyrosine residues, located in helices 4 and 7, are essential for full activity, but not for IAPS-forskolin binding of the GLUT4.

Affinity Labels↗
PubMed1994

Cloning of two novel ADP-ribosylation factor-like proteins and characterization of their differential expression in 3T3-L1 cells.

A polymerase chain reaction-based cloning approach was employed in order to identify ADP-ribosylation factors (ARF) in murine 3T3-L1 cells and to study their expression before and after differentiation of cells to the adipocyte-like phenotype. Partial sequences comprising the effector domains of ARF were amplified with degenerate primers and cloned. Five of these sequences were identified as murine homologues of known human ADP-ribosylation factors (ARF 1, 2, 4, 5, and 6). In addition, partial sequences of two previously unknown isoforms were found, and complete cDNA clones were isolated from a rat fat cell library and were sequenced. Both sequences harbor a putative myristoylation site in position 2, the known consensus sequences presumably involved in GTP binding and hydrolysis, and lack cysteine residues in the C terminus. Their amino acid sequences share a 56 and 41% identity, respectively, with human ARF 1. Based on a comparison with the known ARF isoforms, the first clone appears to represent the mammalian homologue of a known sequence from Drosophila (dARL 1, 79% identity) and was therefore designated rARL 1. The second clone resembled none of the known ARF-like proteins and was designated rARL 4. mRNA of ARL 4 was undetectable in the fibroblasts but abundant in the adipocyte-like phenotype, its expression starting on day 6 of the differentiation. In contrast, ARF 1, 2, and 5 were unaltered by differentiation of the 3T3-L1 cells; mRNA levels of ARF 6, and also of ARL 1 and ARF 4, were reduced after differentiation. It is suggested that the function of ARL 4 is related to the adipocyte-like phenotype of 3T3-L1 cells.

3T3 Cells↗