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Biomedical subjects

R Rudolph

Publications and source records attributed to R Rudolph.

At least 127 records · Page 7Linked to original sources
PubMed1989

[A modification of the ABC method (avidin-biotin-peroxidase complex) for the detection of viral antigens in coronavirus infections in cats (FIP) and parvovirus type 2 infections in dogs].

A modified ABC-method (avidin-biotin-peroxidase complex) is established to demonstrate viral antigens in paraffin sections of tissues of coronavirus (FIP) infected cats and parvovirus type 2 infected dogs using monoclonal antibodies. The pros and cons and potential sources of error are described and discussed.

Animals↗
PubMed1989

Comparative growth dynamics and actin concentration between cultured human myofibroblasts from granulating wounds and dermal fibroblasts from normal skin.

The normal contraction of open wounds and many forms of pathologic contracture are related by the presence of a contractile fibroblast known as a myofibroblast. The function of this cell has been postulated as a result of previous pharmacological, immunological, and biochemical testing on strips of contracted connective tissue. The purpose of this study was to develop a specific assay that could measure the concentration of one contractile element (actin) within cultured myofibroblasts isolated from a contracting wound and in normal fibroblasts from uninjured dermis. Rates of growth and actin concentration through 15 days of culture were compared among populations of paired control fibroblasts from normal dermis and granulating wound myofibroblasts from three patients. Growth curves showed that myofibroblasts always grew slower than fibroblasts. An enzyme-linked immunosorbent assay showed that actin concentration was generally greater in mass cultures of granulating wound myofibroblasts than in fibroblasts from uninjured dermis. During exponential growth (1-6 days) the average actin concentration among myofibroblast lines ranged from 24 to 62 pg/cell. Average actin levels among control fibroblasts ranged from 3 to 47 pg/cell during the same interval. After 15 days of culture, actin concentration peaked twice. The first actin peak occurred within the period of exponential growth. At confluency, cellular actin levels dropped. Superconfluent cultures exhibited a second actin peak that displayed an irregular pattern of actin concentration. The latter observation suggested an artifact that might be the result of three-dimensional matrix of cells that altered points of cell adhesion and produced an irregular pattern of actin concentration. These data show that the phenotype of increased actin in cultured myofibroblasts was carried over by myofibroblasts from contracted skin wounds to culture. Because of a higher concentration of actin in myofibroblasts than in undifferentiated fibroblasts, these data suggest that the differentiation process of myofibroblasts may be associated with an increased availability of monomeric actin for filament synthesis. This study demonstrates that the use of tissue culture and our enzyme-linked immunosorbent assay will be a useful method to study factors affecting myofibroblast phenotypic modulation. Future studies should be directed toward developing procedures for isolation of pure populations of myofibroblasts as well as extracellular matrices that would maintain the morphology of both differentiated myofibroblasts and normal undifferentiated fibroblasts.

Actins↗
PubMed1989

Pneumoperitoneum and an acute abdominal condition caused by spontaneous perforation of a pyometra in an elderly woman: a case report.

Pyometra, a collection of purulent material in the uterus, is an uncommon gynecologic entity. Spontaneous perforation of the uterus is an infrequent complication of pyometra, most often the result of malignant conditions in the uterus. We report the case of an elderly woman who had an acute abdominal condition and pneumoperitoneum due to a ruptured pyometra resulting from a degenerative and infected leiomyoma. Although uterine disease is a rare cause of an acute abdominal condition and pneumoperitoneum in the elderly, a perforated pyometra must be considered in the differential diagnosis.

Abdomen, Acute↗
PubMed1988

[Cotton thread method for measuring tear secretion, suitable for soft contact lens wearers (method no. 3)].

Two methods of measuring lacrimation with a cotton thread and fluorescein have been described hitherto. Method 3 is intended for testing lacrimal flow in wearers of soft contact lenses. Fluorescent paper can be used to facilitate the measuring procedure. The method has been shown to be reliable in numerous control tests on subjects with normal eyes and in comparisons with the authors' methods 1 and 2. With the test, values of less than 5 mm indicate severe lacrimal deficiencies.

Adolescent↗
PubMed1988

Slowed growth of cultured fibroblasts from human radiation wounds.

To study radiation effect separate from the microcirculation, fibroblasts were cultured from four patients with radiation wounds. Cells could be grown from irradiated tissue near the ulcer and from control normal tissue, but no cells could be cultured from the ulcers. The ability of radiation-treated fibroblasts to attach to the substrate and form colonies was less than that of unirradiated cells. Irradiated skin fibroblasts from the four patients had significantly longer mean generation times than did control cells. During log-phase growth (1 to 9 days), the population doublings of damaged cells were significantly reduced compared to colonies from normal cells. These data suggest a permanent intrinsic radiation effect on fibroblasts or a selective ablation of faster-growing fibroblast subpopulations that is not dependent on decreased blood supply.

Aged↗
PubMed1988

Evaluation of an enzyme-linked immunosorbent assay to actin in cultured fibroblasts.

The amount of actin in cultured human skin fibroblasts was determined by an enzyme-linked immunosorbent assay. Absorbance values (OD), resulting from specific binding of an antiactin monoclonal antibody to intracellular actin, were converted to cell concentrations (pg/cell) from an actin standard curve. Actin concentration for cultured human skin fibroblasts by this technique was estimated to be 55.5 picograms/cell and constituted approximately 3.9% of the total cellular protein. This assay procedure offers the following advantages: (1) It is time efficient, can be completed in 2-3 hours; (2) cells are unaltered except for membrane permeabilization; (3) the sensitivity is equal to or greater than previous procedures involving gel electrophoresis; and (4) the assay is easy and inexpensive to perform.

Actins↗
PubMed1987

Proteolytic dimers of porcine muscle lactate dehydrogenase: characterization, folding, and reconstitution of the truncated and nicked polypeptide chain.

Lactate dehydrogenase from porcine skeletal muscle is a "dimer of dimers" that is stabilized in its tetrameric state by an N-terminal "arm" of approximately 20 amino acid residues. Due to the low dissociation constant of the tetramer, the dimer is inaccessible to direct analysis. Limited proteolysis during reconstitution (after dissociation at pH 2.3) yields stable "dimers". As suggested by affinity chromatography, these inactive dimers contain the dinucleotide fold of native LDH. In the presence of structure-making ions, approximately 40% activity is restored in the dimeric state [Girg, R., Jaenicke, R., & Rudolph, R. (1983) Biochem. Int. 7, 443-444]. The cleavage yields about equal amounts of three fragments, F 34, F 21, and F 14 (Mr 33.5K, 21.4K, and 13.5K, respectively). F 34 represents the intact chain lacking the N-terminal 10-11 amino acid residues; its C-terminus is heterogeneous, varying in the range between residues 326 +/- 5. F 21 contains residues 11/12 to 200 +/- 3; F 14 is a mixture of three subfragments: residues 11/12 to approximately 133, 38 to approximately 163, and 208 to approximately 327. After solubilization in 6 M guanidine hydrochloride, F 34 can be reconstituted to partially active dimers. Reactivation is determined by slow subunit refolding with subsequent diffusion-controlled dimerization, in accordance with the monomer-dimer transition in the reconstitution mechanism of the intact tetramer. Reconstitution of F 21 and F 14 is concentration dependent and leads to partially active "nicked dimers", indicating that separate domains are able to reassociate correctly to yield the native subunit arrangement.

Amino Acid Sequence↗
PubMed1987

Etiology and treatment of chemotherapeutic agent extravasation injuries: a review.

While extravasation from intravenous (IV) lines is common and usually benign, leakage of certain drugs can cause severe skin ulceration. These ulcerogenic drugs can be conveniently divided into two categories, depending on whether they bind to DNA. Chemotherapeutic agents such as doxorubicin, which bind to DNA, are especially prone to cause severe extravasation skin ulcers. These ulcers are often chronic and progressive. Neither clinical nor experimental studies have shown an antidote to doxorubicin extravasation, which is best prevented by careful technique. If extravasation is suspected, the infusion should be immediately stopped. In the event of extravasation, elevation and ice are the currently recommended treatment. While small ulcerations may on occasion heal, large ulcerations require surgical excision for relief of pain and salvage of underlying tissues.

Antineoplastic Agents↗
PubMed1987

Wide spread scars, hypertrophic scars, and keloids.

Patients with a wide scar may complain of having a "keloid," yet have a hypertrophic or a wide spread scar. The plastic surgeon should make the appropriate clinical diagnosis, because therapy varies depending on the condition present. A wide spread scar is best treated with excision and closure. A buried dermal flap may help to prevent recurrence, which is nevertheless likely to some degree. A hypertrophic scar can be distinguished from a keloid on clinical grounds. Although both may be red, nodular, and itchy, the keloid overgrows the original wound boundary and is much more likely to recur after surgical excision. Nonsurgical treatment of hypertrophic scars and keloids is similar, using repeated intralesional injections of Kenalog 40 mg per cc and sustained pressure on the lesion when possible. Surgical treatment differs for hypertrophic scars or keloids. Scar excision and closure, and selective Z-plasty, may be used in hypertrophic scars. In keloids, aggressive surgery is usually avoided, unless the lesion has a narrow pedicle. Surgery of keloids should be accompanied by intra- and postoperative Kenalog-40 injections, and on occasion by sustained pressure. Very large keloids may be resistant to medical management, and too aggressive for surgery owing to a high likelihood of recurrence. These difficult lesions serve as the impetus for continued biochemical and tissue culture research, seeking a biochemical means of control keloids.

Adult↗
PubMed1986

Dissociation and in vitro reconstitution of bovine liver uridine diphosphoglucose dehydrogenase. The paired subunit nature of the enzyme.

Uridine diphosphoglucose dehydrogenase (EC 1.1.1.22: UDPglucose dehydrogenase) at pH 5.5-7.8 is a stable homohexamer of 305 +/- 7 kDa that does not undergo concentration-dependent dissociation at enzyme concentrations greater than 5 micrograms/mL. Chemical cross-linking of the native enzyme at varying glutaraldehyde concentrations yields dimers, tetramers, and hexamers; at greater than 2% (w/v) glutaraldehyde, plateau values of 21% monomers, 16% dimers, 5% tetramers, and 58% hexamers are obtained. Dissociation at acid pH (pH 2.3) or in 4-6 M guanidine hydrochloride leads to inactive monomers (Mr 52,000). Denaturation at increasing guanidine hydrochloride concentration reveals separable unfolding steps suggesting the typical domain structure of dehydrogenases holds for the present enzyme. At greater than 4 M guanidine hydrochloride complete randomization of the polypeptide chains is observed after 10-min denaturation. Reconstitution of the native hexamer after dissociation/denaturation has been monitored by reactivation and glutaraldehyde fixation. The kinetics may be described in terms of a sequential uni-bimolecular model, governed by rate-determining folding and association steps at the monomer level. Trimeric intermediates do not appear in significant amounts. Reactivation is found to parallel hexamer formation. Structural changes during reconstitution (monitored by circular dichroism) are characterized by complex kinetics, indicating the rapid formation of "structured monomers" (with most of the native secondary structure) followed by slow "reshuffling" prior to subunit association. The final product of reconstitution is indistinguishable from the initial native enzyme.

Animals↗
PubMed1986

Reassociation of dimeric cytoplasmic malate dehydrogenase is determined by slow and very slow folding reactions.

Malate dehydrogenase occurs in virtually all eucaryotic cells in mitochondrial and cytoplasmic forms, both of which are composed of two identical subunits. The reactivation of the mitochondrial isoenzyme has been the subject of previous studies [Jaenicke, R., Rudolph, R., & Heider, I. (1979) Biochemistry 18, 1217-1223]. In the present study, the reconstitution of cytoplasmic malate dehydrogenase from porcine heart after denaturation by guanidine hydrochloride has been determined. The enzyme is denatured by greater than 1.2 M guanidine hydrochloride; upon reconstitution, approximately 60% of the initial native enzyme can be recovered. The kinetics of reconstitution after maximum unfolding by 6 M guanidine hydrochloride were analyzed by fluorescence, far-ultraviolet circular dichroism, chemical cross-linking with glutaraldehyde, and activity measurements. After fast folding into structured intermediates (less than 1 min), formation of native enzyme is governed by two parallel slow and very slow first-order folding reactions (k1 = 1.3 X 10(-3) S-1 and k2 = 7 X 10(-5) S-1 at 20 degrees C). The rate constant of the association step following the slow folding reaction (determined by k1) must be greater than 10(6) M-1 S-1. The energy of activation of the slow folding step is of the order of 9 +/- 1 kcal/mol; the apparent rate constant of the parallel very slow folding reaction is virtually temperature independent. The intermediates of reassociation must be enzymatically inactive, since reactivation strictly parallels the formation of native dimers. Upon acid dissociation (pH 2.3), approximately 35% of the native helicity is preserved, as determined by circular dichroism.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

(11; 14) translocation in three boys with acute lymphoblastic leukemia of T-cell immunophenotype.

Three boys, 12, 15 and 5 years old are presented with acute lymphoblastic leukemia resp. Non-Hodgkin's lymphoma with leukemic transformation. Blast cells could be characterized as being of T-cell origin. Hand mirror variant was the predominant morphologic feature of the blast cells in two patients. Chromosome analysis of the leukemic blast cells revealed a pseudodiploid (modal chromosome number = 46) karyotype in two patients and a pseudotetraploid (modal chromosome number = 92) in one patient. A chromosome translocation (11; 14) with breakpoints at (p 13; q 13) (within the human T-cell receptor alpha chain locus!) was found in the leukemic cells of all three cases plus an additional t (7; 9) (q 22; p 13) in one patient.

Adolescent↗