Search PubMed⌕ Search

Biomedical subjects

K Weber

Publications and source records attributed to K Weber.

At least 451 records · Page 25Linked to original sources
PubMed1985

A monoclonal antibody recognizing desmosomes: use in human pathology.

A mouse monoclonal IgG1 antibody that recognizes desmosomes in human tissues has been isolated and characterized. DP1 recognizes desmoplakin I (250 kD) in immunoblots of partially purified desmosome preparations. In immunofluorescence microscopy DP1 reacts with desmosomes in epithelial cells from a variety of human tissues including skin, esophagus, uterus, intestine, and in liver hepatocytes. In axilla skin, the epithelial cells in epidermis, sweat glands, and in the outer hair follicles are strongly stained whereas relatively little staining is seen in the epithelial cells of the apocrine glands. Nonepithelial cells are not stained, although decoration of myocardial desmosomes is seen. In cells in culture DP1 is also specific for desmosomes in epithelial cells. Thus the mouse epidermal line HEL, bovine MBCK cells, as well as the human lines A431, HT29, and HeLa are positively stained by DP1. Desmosomes are retained in tumors of epithelial origin such as adenocarcinoma and squamous cell carcinoma. Thus DP1 should be a useful diagnostic marker in human pathology.

Animals↗
PubMed1985

An ultrastructural and immunohistological study of the rat olfactory epithelium: unique properties of olfactory sensory cells.

The olfactory epithelium contains three cell types: basal cells, supporting cells and sensory neurons. Electron microscopy as well as immunofluorescence microscopy with intermediate-filament antibodies were used to study the rat olfactory epithelium in order to obtain more information about these different cell types and to try to investigate their histogenetic origins. We found mitoses in the basal-cell layer, as well as multiple centrioles and tonofilaments in some basal cells. As revealed by electron microscopy, the supporting cells contained tonofilaments and reacted strongly with antibodies to keratin, in line with their known epithelial nature. When antibodies to other intermediate-filament types were used, i.e. glial fibrillary acidic protein, vimentin, desmin and neurofilaments, no reaction was seen in the cells of the olfactory epithelium, with the exception of occasional staining of a few axons in the subepithelial layer by neurofilament antibodies. In particular, the cell bodies, dendrites and most axons of the sensory neurons were negative for a variety of antibodies against neurofilaments. Olfactory sensory neurons therefore belong to the very few cells in adult animals which seem to lack intermediate filaments. We discuss whether this finding is related to the fact that these cells are also unique among neurons in that they are not permanent cells but constantly turn over.

Animals↗
PubMed1985

Golgi-derived membranes that contain an acylated viral polypeptide are used for vaccinia virus envelopment.

A 37,000-dalton polypeptide (p37K) present on purified extracellular vaccinia virus but absent from intracellular virus particles of classical morphology (G. Hiller et al., J. Virol. 39:903-913, 1981; L. G. Payne, J. Virol. 27:28-37, 1978) was further characterized. The polypeptide was only expressed in infected cells after onset of viral DNA replication. Phase partition experiments showed that it is relatively hydrophobic. Although p37K apparently is not a glycoprotein, in vivo radioisotope labeling detected tightly associated palmitic acid. Antibodies to p37K were used to monitor its distribution within infected cells at the light and electron microscopic levels. After synthesis p37K first accumulated in the Golgi region due to a tight membrane association. During progressing infection p37K-carrying membranes were used to form double-walled envelopes around brick-shaped vaccinia particles. Within these specialized vesicles vaccinia particles were moved through the cytoplasm toward the cell's surface, presumably along cellular routes for certain secretory products. Finally, single enveloped viruses were released into the extracellular space by an exocytotic process.

Amino Acids↗
PubMed1985

Adult norms for the Box and Block Test of manual dexterity.

The Box and Block Test, a test of manual dexterity, has been used by occupational therapists and others to evaluate physically handicapped individuals. Because the test lacked normative data for adults, the results of the test have been interpreted subjectively. The purpose of this study was to develop normative data for adults. Test subjects were 628 Normal adults (310 males and 318 females) from the seven-county Milwaukee area. Data on males and females 20 to 94 years old were divided into 12 age groups. Means, standard deviations, standard error, and low and high scores are reported for each five-year age group. These data will enable clinicians to objectively compare a patient's score to a normal population parameter.

Adult↗
PubMed1985

Microinjection of monoclonal antibodies specific for one intermediate filament protein in cells containing multiple keratins allow insight into the composition of particular 10 nm filaments.

Monoclonal antibodies specific for vimentin (V9), keratin 7 (CK 7) and keratin 18 (CK5) have been microinjected into three human epithelial cell lines: HeLa, MCF-7 and RT-4. The effect of the injection on other keratin polypeptides and vimentin filaments has been observed by double label immunofluorescence and in some instances by immunoelectron microscopy using gold labels of different sizes. Microinjection of V9 into HeLa cells causes the vimentin to collapse into a perinuclear cap leaving the keratin filaments unaffected. Injection of CK5 does not affect the vimentin filaments but disrupts the keratin filaments revealing keratin aggregates similar to those seen in some epithelial cell lines during mitosis. The keratin aggregates obtained after microinjection in HeLa contain the keratins 8 and 18 and probably also other keratins, as no residual keratin filaments are observed with a keratin polyclonal antibody of broad specificity. Aggregates in mitotic HeLa cells contain at least the keratins 7, 8, and 18. In MCF-7 cells keratins 8, 18, and 19 are observed in the aggregates seen 3 h after microinjection which, however, show a different morphology from those seen in HeLa cells. In MCF-7 cells a new keratin filament is built within 6 h after the injection which is composed mainly of keratin 8 and 19. The antibody-complexed keratin 18 remains in spherical aggregates of different size. The results suggest that in HeLa cells vimentin and keratin form independent networks, and that individual 10 nm filaments in epithelial cell lines can contain more than two keratins.

Animals↗
PubMed1985

Desmin is a specific marker for rhabdomyosarcomas of human and rat origin.

Putative human rhabdomyosarcoma (RMS) has been divided into two groups according to desmin content. Twenty-five tumors with histologic features consistent with but not necessarily sufficient to prove a diagnosis of RMS were desmin-positive. More than 95% of the tumor cells were desmin-positive, suggesting a muscle origin and supporting the diagnosis of RMS. Nine tumors for which the preferred first histologic diagnosis was also RMS were desmin-negative. Reexamination of the original histologic slides together with results from intermediate filament typing resulted in a diagnosis other than RMS for all tumors in this second group, and in several instances other tests were used to prove the correctness of the final diagnosis. The results on human material were extended to a rat model system in which RMS was induced by nickel sulfide. Again, all 24 tumors tested were desmin-positive. Vimentin was coexpressed in a varying percentage of tumor cells in RMS of human and rat origin. The results show that desmin is an excellent marker for rhabdomyosarcoma, yielding few if any false-positive or false-negative results in frozen or alcohol-fixed material.

Adolescent↗
PubMed1985

Cytoskeletal proteins at the cholinergic synapse: distribution of desmin, actin, fodrin, neurofilaments, and tubulin in Torpedo electric organ.

Treatment of the electric organ of Torpedo marmorata with Triton X-100 in the presence of 2 mM MgCl2 generated a cytoskeletal fraction in which a 54 kDa polypeptide is a major constituent. This 54 kDa polypeptide accounted for about 8% of the cellular protein when total electric organ tissue was analyzed by two-dimensional gel electrophoresis. Immunoblotting experiments showed that this protein reacts with monoclonal antibodies to desmin, the major intermediate filament protein of avian and mammalian muscle tissue. Negative stain analysis revealed that filaments of about 10 nm diameter are the major structural elements of the electric organ cytoskeleton. In the presence of Ca2+ there was a rapid degradation of the desmin-like protein and intermediate filaments due to a Ca2+-activated protease. Some of the resulting fragments retained antigenic activity against the desmin antibodies. Immunoblotting of membrane fractions enriched in acetylcholine receptor revealed desmin in addition to some actin. A further cytoskeletal component was identified from biochemical and immunological properties as a homologue of the mammalian neurofilament L-polypeptide. Thus Torpedo expresses proteins homologous to the mammalian desmin and neurofilament L-protein which can be detected using immunological approaches. Immunofluorescence microscopy was used to map the location of various cytoskeletal proteins of the cholinergic synapse on paraffin sections and on en face preparations of membranes. Desmin staining was restricted to electrocytes and in en face preparations was seen associated with both the ventral receptor-containing membrane and with the non-innervated dorsal membrane. Antibodies to neurofilament L-protein stained only the axons and not the electrocytes. Staining for fodrin, a non-erythrocyte spectrin, resulted in submembraneous decoration of both the axons and the electrocytes. Axonal staining for neurofilaments and microtubules did not extend into the ends of the nerve terminal arborizations.

Actins↗
PubMed1985

An immunofluorescence study of neurofilament protein expression by developing hippocampal neurons in tissue culture.

We have studied the development of intermediate filament proteins in the neurons found in hippocampal cell cultures using single and double label immunofluorescence with both monoclonal and polyclonal antibodies. Neurons in these cultures are known to differentiate in a manner similar to their counterparts in situ: in particular they develop axonal and dendritic processes which differ from each other in form, in ultrastructure, and in synaptic polarity. During the first days in culture, developing neurons could not be stained with antibodies against any of the neurofilament proteins, although many cells reacted with anti-vimentin. Later in the first week, antibody staining revealed clearly filamentous staining for the L (68 000 daltons) and the M (145 000 daltons) neurofilament subunits, though M reactivity was much stronger at this earlier stage of development. Some neurofilament positive profiles in many cells could also be stained with vimentin, though the vimentin immunoreactivity became progressively less pronounced during further development, and disappeared after about two weeks in culture. Also at about two weeks in vitro we noted the first appearance of neurofilament H protein (200 000 daltons) immunoreactivity, which was localized to a subset of long neurites which could be identified on morphological grounds as axons. These processes lacked staining for microtubule associated protein 2 (MAP2), a dendritic marker. They tended to be close to islands of glial cells, suggesting that H induction may require complex neuron-glial interactions. These results are consistent with the suggestion that H protein immunoreactivity is a marker for axonal outgrowth. In addition to obvious filamentous staining, we were able to localize neurofilament antigens to an interesting class of small ring-like structures, found increasingly frequently as the cultures aged. We also present evidence that tyrosinated alpha-tubulin is present both within dendrites and axons of neurons in these cultures.

Animals↗
PubMed1985

Grip and pinch strength: normative data for adults.

The primary purpose of this study was to establish clinical norms for adults aged 20 to 75+ years on four tests of hand strength. A dynamometer was used to measure grip strength and a pinch gauge to measure tip, key, and palmar pinch. A sample of 310 male and 328 female adults, ages 20 to 94, from the seven-county Milwaukee area were tested using standardized positioning and instructions. Right hand and left hand data were stratified into 12 age groups for both sexes. This stratification provides a means of comparing the score of individual patients to that of normal subjects of the same age and sex. The highest grip strength scores occurred in the 25 to 39 age groups. For tip, key, and palmar pinch the average scores were relatively stable from 20 to 59 years, with a gradual decline from 60 to 79 years. A high correlation was seen between grip strength and age, but a low to moderate correlation between pinch strength and age. The newer pinch gauge used in this study appears to read higher than that used in a previous normative study. Comparison of the average hand strength of right-handed and left-handed subjects showed only minimal differences.

Adult↗
PubMed1985

[Infant hypotonia, obesity, hypogenitalism and oligophrenia--new viewpoints on the etiology and symptoms of Prader-Willi syndrome].

We present four cases of Prader-Willi syndrome. Two of them have an abnormality of a chromosome 15, the other both show different chromosomal abnormalities. Translocations or deletions were found recently in the bands 15q11/12 in about 60% of the cases of Prader-Willi syndrome. The consequences for diagnosis, symptomatology and genetic counselling of the syndrome are discussed.

Child↗
PubMed1984

Chordate muscle actins differ distinctly from invertebrate muscle actins. The evolution of the different vertebrate muscle actins.

A total of 30 actins from various chordate and invertebrate muscle sources were either characterized by full amino acid sequence data or typed by those partial sequences in the NH2-terminal tryptic peptide which are known to be specific markers for different actin isoforms. The results show that most, if not all, invertebrate muscle actins are homologous to each other and to the isoforms recognized as vertebrate cytoplasmic actins. In contrast the actin forms typically found in muscle cells of warm-blooded vertebrates are noticeably different from invertebrate muscle actins and seem to have appeared in evolution already with the origin of chordates. During subsequent vertebrate evolution there has been a high degree of sequence conservation similar or stronger than that seen in histone H4. Urochordates, Cephalochordates and probably also Agnathes express only one type of muscle actin. Two types, a striated muscle-specific form and a smooth muscle form, are already observed in Chondrichthyes and Osteichthyes. Later in evolution, with the origin of reptiles, both muscle actins seem to have duplicated again; the striated muscle type branched into a skeletal- and cardiac-specific form, while the smooth muscle form duplicated into a vascular- and stomach-specific type. These findings support the hypothesis that each of the four muscle actins of warm-blooded vertebrates are coded for by a small number and possibly only one functional gene.

Actins↗
PubMed1984

SDS-PAGE strongly overestimates the molecular masses of the neurofilament proteins.

Direct molecular mass determination of the three porcine neurofilament proteins (H, M and L) was performed in 6 M guanidine-HCl using analytical gel filtration and sedimentation equilibrium centrifugation. The results show that SDS-PAGE strongly overestimates the values of the 'higher molecular mass' components H and M. This discrepancy stems from the carboxyterminal extensions known to have unusual amino acid composition.

Animals↗
PubMed1984

Diagnostic value of intermediate filament antibodies in clinical cytology.

Antibodies to intermediate filament (IF) proteins can distinguish the major tumour groups as shown by results with sectioned human material. In this study we evaluate the use of similar methods in the cytology of human tumors. Smears obtained from fine needle aspiration biopsies were investigated using well characterized antibodies, each specific for only one of the five types of intermediate filaments. Tumor cells of different carcinomas, thymomas, and the epithelial part of pulmonary blastomas were positive with antibodies recognizing cytokeratins. Tumor cells in non-muscle sarcomas, including lymphoma and Ewing's sarcoma, could be specifically identified with antibodies to vimentin. Tumor cells of muscle sarcomas were desmin-positive. Finally, tumor cells in pheochromocytoma and bronchus carcinoid were positive with antibodies specific for neurofilaments. Specimens were also examined in parallel using conventional cytochemical stains, such as May-Grünwald-Giemsa. In addition, in most cases sections of the tumor were examined both by histology and IF typing of frozen sections to confirm the diagnosis made on the cytologic specimens. The results show that IF typing is a valuable diagnostic aid in clinical cytology.

Adolescent↗