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Biomedical subjects

K Gruber

Publications and source records attributed to K Gruber.

At least 19 recordsLinked to original sources
PubMed1997

Chorionic villi or trophoblastic tissue in uterine samples of four women with ectopic pregnancies.

The diagnosis of early ectopic pregnancy remains challenging for the gynecologist. Although early detection of a suspected pregnancy has been facilitated by quantitative beta human chorionic gonadotropin studies and ultrasonography, a patient subgroup remains with an ambiguous presentation. In this group of patients, the clinician must rely on microscopic examination of products of conception in a uterine curettage specimen to rule out the presence of an extrauterine pregnancy. The presence of an implantation site, chorionic villi, or trophoblastic tissue in uterine curettage samples is conventionally held as definitive evidence of an intrauterine pregnancy. We present a series of four cases that challenge this convention. In these cases, chorionic villi or an implantation site were identified in uterine samples of pregnant women who each ultimately proved to have an ectopic pregnancy. If clinical suspicion is high, the finding of either chorionic villi or an implantation site should not preclude further workup of a possible ectopic pregnancy. In cases where only a few villi or a single chorionic villus are identified, other signs of intrauterine implantation such as intermediate trophoblastic cells, hyalinized vessels, and a fibrinoid matrix should be sought to establish firmly the diagnosis of an intrauterine pregnancy.

Adult↗
PubMed1995

The human replacement histone H3.3B gene (H3F3B).

H3.3 is a replacement histone subtype that is encoded by two replication-independent genes termed H3.3A and H3.3B, respectively. We have isolated a fullsize H3.3 cDNA clone from an oligo(dT)-primed human testicular cDNA library. Subsequently, the corresponding gene was isolated from a human cosmid library and was identified as the H3.3B gene. It was the only histone gene on this 42-kb cosmid clone. The gene structure shows characteristic features of an H3.3 gene. First, it contains an intron of about 0.5 kb in the 5' untranslated region and two smaller introns within the coding gene portion. Second, no histone gene-specific dyad symmetry element was found in the 3' untranslated region, but three putative polyadenylation signals were detected downstream of the gene. The corresponding transcripts were detected by Northern blot analysis using poly(A)+ RNA from testis and from the HEK293 tumor cell line. The newly discovered human H3.3B gene (HGMW-approved symbol H3F3B) was mapped by fluorescence in situ hybridization to the telomeric region of chromosome 17 (17q25). This localization of the H3.3B gene and its solitary arrangement contrast with the majority of the replication-dependent histone genes, which form a large cluster on chromosome 6 and a second cluster on chromosome 1.

Amino Acid Sequence↗
PubMed1994

[Angiomyolipoma of the kidney. Value of diagnosis in acute hemorrhage].

We report about a severe retroperitoneal bleeding of a ruptured angiomyolipoma of kidney. Despite of maximal diagnostic effort including CT and angiography it was not possible to find the exact diagnosis preoperative. The extensive bleeding did not allow to resect only the tumor, nephrectomy was necessary.

Adult↗
PubMed1993

[Brush biopsy as a new examination method of the upper respiratory tract in cattle and swine].

Several techniques of cytobrush sampling were developed for morphological examination of upper respiratory tract epithelium in cattle and swine. These techniques were evaluated in 30 cattle and swine each, with an age of two weeks to nine years and three weeks to four years respectively. Optimal anatomical locations for sampling were determined. Three cytobrushes of different shapes were constructed to optimize sampling in animals of different ages. Two out of four cytobrush sampling techniques developed provided sufficient cellular material and worked well under field conditions. Rinsing with 0.9% saline largely eliminated mucus and other interfering substances.

Animals↗
PubMed1992

Evidence for an S-layer protein pool in the peptidoglycan of Bacillus stearothermophilus.

Intact cells of Bacillus stearothermophilus PV72 revealed, after conventional thin-sectioning procedures, the typical cell wall profile of S-layer-carrying gram-positive eubacteria consisting of a ca. 10-nm-thick peptidoglycan-containing layer and a ca. 10-nm-thick S layer. Cell wall preparations obtained by breaking the cells and removing the cytoplasmic membrane by treatment with Triton X-100 revealed a triple-layer structure, with an additional S layer on the inner surface of the peptidoglycan. This profile is characteristic for cell wall preparations of many S-layer-carrying gram-positive eubacteria. Among several variants of strain PV72 obtained upon single colony isolation, we investigated the variant PV72 86-I, which does not exhibit an inner S layer on isolated cell walls but instead possesses a profile identical to that observed for intact cells. In the course of a controlled mild autolysis of isolated cell walls, S-layer subunits were released from the peptidoglycan of the variant and assembled into an additional S layer on the inner surface of the walls, leading to a three-layer cell wall profile as observed for cell wall preparations of the parent strain. In comparison to conventionally processed bacteria, freeze-substituted cells of strain PV72 and the variant strain revealed in thin sections a ca. 18-nm-wide electron-dense peptidoglycan-containing layer closely associated with the S layer. The demonstration of a pool of S-layer subunits in such a thin peptidoglycan layer in an amount at least sufficient for generating one coherent lattice on the cell surface indicated that the subunits must have occupied much of the free space in the wall fabric of both the parent strain and the variant. It can even be speculated that the rate of synthesis and translation of the S-layer protein is influenced by the packing density of the S-layer subunits in the periplasm of the cell wall delineated by the outer S layer and the cytoplasmic membrane. Our data indicate that the matrix of the rigid wall layer inhibits the assembly of the S-layer subunits which are in transit to the outside.

Cell Wall↗
PubMed1992

Technique-dependent variations in cerebral microvessel blood volumes and hematocrits in the rat.

To quantitate small parenchymal microvessel blood volumes in the brain, the distribution spaces of radiolabeled red blood cells (RBC) and serum albumin (RISA) were assessed in rats by different methods of tissue sampling and radioassay. Three minutes after intravenous administration of 55Fe-RBCs and/or 125I-RISA, the rats were decapitated. The brain was either immediately frozen within the skull and later removed (head-frozen group) or rapidly removed from the skull and then frozen (brain-frozen group). Radioactivity was measured either by liquid scintillation counting of tissue pieces, which contained pial plus large and small parenchymal microvessels, or by quantitative autoradiography (QAR) of tissue sections, which indicated small parenchymal microvessel blood only. In 12 of 15 areas, the RISA, RBC, and blood volumes determined by liquid scintillation counting of head-frozen tissue pieces were equal to or greater than those of brain-frozen tissue; this indicated less than or equal to 25% greater blood retention in pial and parenchymal microvessels with head freezing. At the parenchymal microvessel level (QAR assay), the distribution volumes of RBCs, RISA, and blood were similar with the two freezing techniques; hence with QAR either freezing procedure can be used to assess small parenchymal microvessel blood volumes.

Animals↗
PubMed1992

[Surgery for pseudarthrosis of the scaphoid bone performed in Hungary 1988].

Authors analyse, based on an all-round inquiry, the operations performed for pseudarthrosis of the scaphoid in 1988. It was found that 344 of 472 operations were reconstructive, 128 palliative. The single types of operation are briefly described. They hint at the fact that the operative treatment of scaphoid pseudarthrosis in Hungary is carried out mostly in Centers.

Carpal Bones↗
PubMed1992

The technique of taking brush biopsies of the nasal mucosa for electron microscopy.

Patients suffering from symptoms suggestive of a disorder of mucociliary clearance should be subjected to electron microscopic examination of the ciliated respiratory epithelium. Provided that all crucial points regarding technique and storage are adhered to, brush biopsy of the nasal mucosa is a reliable method facilitating the electron microscopical diagnosis of primary disorders of the ciliated epithelium.

Biopsy↗
PubMed1991

Influence of an S-layer on surface properties of Bacillus stearothermophilus.

Various aspects of surface properties of the S-layer-carrying Bacillus stearothermophilus PV72 and of an S-layer-deficient mutant (strain PV72/T5) have been tested by adsorption assays on solid surfaces, electrostatic interaction chromatography and hydrophobic interaction chromatography. The adsorption assays have shown that cell adhesion of the S-layer-carrying strain was less influenced by environmental changes than it was with the S-layer-deficient mutant. Electrostatic interaction chromatography indicated that both strains have positively and negatively charged groups exposed on the cell surface but the S-layer-carrying strain reveals more positively charged groups than does the S-layer-deficient mutant. Hydrophobic interaction chromatography showed that both strains have a hydrophilic surface but that the hydrophilic properties are more pronounced with the strain lacking an S-layer.

Bacterial Adhesion↗
PubMed1991

The effects of chronic serum sickness on albumin distribution and glucose utilization in rat brain.

The level of cerebrospinal fluid (CSF) protein is elevated in diseases and disease models that are associated with circulating immune complexes such as serum sickness. Circulatory immune complexes are known to deposit in the basal lamina of fenestrated capillaries and may, as a result, affect both capillary bed and parenchymal function. Since the brain has both fenestrated and unfenestrated capillaries and immune complexes deposit to a varying extent in the fenestrated capillaries in chronic serum sickness, cerebral capillary permeability to protein may be altered in some brain areas and lead to the elevation of CSF proteins. In addition various other cerebrovascular and metabolic functions may also be affected by this condition. In this study either radio-iodinated serum albumin (RISA) or 2-[14C]deoxyglucose (14C-2DG) was intravenously injected into control Wistar rats and Wistar rats with chronic serum sickness; subsequently the tissue levels of radioactivity were measured by quantitative autoradiography in 4 brain areas with fenestrated capillaries and 11 brain areas with unfenestrated capillaries. The 2-min distribution of RISA, which demarcates the volume of circulating plasma in perfused microvessels and is generally proportional to local plasma flow, was the same in control and experimental rats. The passage of RISA from blood into brain over 30 min was negligible in both groups; thus cerebral capillary permeability to albumin was not detectably increased in any of these 15 brain areas by chronic serum sickness. The rate of local cerebral glucose utilization, an indicator of local metabolic and neural activity, was calculated from the 14C-2DG data and was virtually identical in control and experimental rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1990

Quantitative autoradiographic assessment of 55Fe-RBC distribution in rat brain.

A simple in vivo technique of labeling erythrocytes (RBCs) with 55Fe was developed for quantitative autoradiography (QAR). This procedure involved injecting 5-6 ml of [55Fe]ferrous citrate solution (1 mCi/ml) intraperitoneally into donor rats. The number of labeled RBCs reached a maximum at around 7 days and declined very slowly thereafter. Labeled RBCs were harvested from donor rats and used for RBC volume measurement in awake rats. Brain radioactivity was assayed by QAR, which yielded spatial resolution of greater than 50 microns. Tight nearly irreversible binding of 55Fe to RBCs was found in vivo and in vitro. More than 99.5% of the 55Fe in the blood of donor rats was bound to RBCs. Because of this, labeled blood can be taken from donors and injected into recipients without further preparation. The tissue absorption of 55Fe emissions was the same in gray and white matter. Microvascular RBC volumes measured with 55Fe-labeled RBCs agreed with those assayed with 51Cr-labeled RBCs for many, but not all, brain areas. In conclusion, 55Fe-RBCs can be readily prepared by this technique and accurately quantitated in brain tissue by QAR.

Animals↗
PubMed1989

Genetic studies on nucleolus organizer regions (NORs) in cattle.

Experimentally produced monozygotic twins, natural opposite sex blood chimeras (freemartins), and several pedigrees were used to evaluate the genetic influences on the nucleolus organizer region (NOR) patterns in cattle. In monozygotic twins, the NOR patterns of both twins are extremely similar. In chimeras, NOR patterns of genetically identical, peripheral blood lymphocytes (PBL) from the two partners resemble each other. In contrast, genetically different PBL (sib organ) differ significantly in the same environment. A high heritability of the individual NOR patterns is also demonstrated in our 23 pedigrees. In conclusion, our data demonstrate that variation in NOR expression is predominantly due to genetic factors.

Animals↗
PubMed1988

Localized insertion of new S-layer during growth of Bacillus stearothermophilus strains.

Bacillus stearothermophilus strains PV 72 and ATCC 12980 carry a crystalline surface layer (S-layer) with hexagonal (p6) and oblique (p2) symmetry, respectively. Sites of insertions of new subunits into the regular lattice during cell growth have been determined by the indirect fluorescent antibody technique and the protein A/colloidal gold technique. During S-layer growth on both bacillus strains the following common features were noted: 1. shedding of intact S-layer or turnover of individual subunits was not seen; 2. new S-layer was deposited in helically-arranged bands over the cylindrical surface of the cell at a pitch angle related to the orientation of the lattice vectors of the crystalline array; 3. little or no S-layer was inserted into pre-existing S-layer at the poles, and 4. septal regions and, subsequently, newly formed cell poles were covered with new S-layer protein.

Bacterial Proteins↗
PubMed1988

Structural and functional variations in capillary systems within the brain.

The major hypothesis of this study is that there are differences among brain areas in capillary bed structure and function. Three general differences between circumventricular organ and non-CVO capillary beds were found. First, the PS products for AIB were about 300 times greater in CVO capillaries than in non-CVO (blood-brain barrier) capillaries. Second, the frequency of endothelial cell fenestrations was much greater in CVO capillaries than in non-CVO capillaries and the fenestrae may be structural modifications of endothelial cells that permit ready passage of solutes such as AIB. Third, the frequency of mitochondria was greater in BBB capillaries than in CVO capillaries; this high metabolic potential of BBB capillaries may be associated, in part, with "carrier-mediated" transport of various solutes between plasma and cerebral interstitial fluid. Capillary bed differences among all (i.e., both CVO and non-CVO) brain structures were also observed. Among these differences are: rate of blood flow, mean transit time of albumin, capillary volume and surface area, perfused microvessel blood volume, apparent percentage of perfused capillaries, PS products for AIB, and frequency within the endothelium of vesicular profiles.

Aminoisobutyric Acids↗
PubMed1987

Forebrain and brainstem afferents to the arcuate nucleus in the rat: potential pathways for the modulation of hypophyseal secretions.

Doxorubicin, an anti-oncogenic agent, was used as a retrograde marker to identify arcuate nucleus afferent projections. Injections of this tracer into the arcuate nucleus indicated that the subfornical organ, the organum vasculosum of the lamina terminalis, the nucleus raphe dorsalis and median raphe send projections to the arcuate nucleus. Immunocytochemical procedures were used to demonstrate that the raphe projections to the arcuate nucleus are serotoninergic. This anatomical investigation provides evidence that neural pathways exist between forebrain body fluid and mineral nuclei, mesencephalic serotonin nuclei and the arcuate nuclei.

Afferent Pathways↗
PubMed1987

Glycocalyceal bodies--a marker for different epithelial cell types in human airways.

The surface epithelium of the mucosa of the nose, sinus maxillaris, trachea and bronchi of the human respiratory tract has been investigated with respect to surface differentiations, glycocalyx and glycocalyceal bodies. The luminal surface mainly is formed by ciliated, undifferentiated, and secretory cells; occasionally metaplastic epithelial regions, composed of flattened squamous cells are found. Ciliated cells as well as differentiating progenitor cells, recognizable by branched, microvillus-like surface differentiations - 'cytofila' which on mature ciliated cells are interposed between the cilia, exhibit a delicate glycocalyx. On the contrary, secretory, undifferentiated, and metaplastic squamous cells possess unbranched microvilli of different length and diameter, and exhibit a prominent glycocalyx of varying, individual expression. These latter cell types, in healthy control persons as well as in patients suffering from different diseases, showed glycocalyceal bodies. By means of the high number of investigated samples, more than 350, the occurrence and distribution of glycocalyceal bodies could be defined more exactly: in all investigated regions of the human respiratory tract--nose, sinus maxillaris, trachea, and bronchi--glycocalyceal bodies were found at the apical surface of undifferentiated cells, secretory cells, and metaplastic squamous cells; ciliated cells and their differentiating progenitor cells never showed glycocalyceal bodies; glycocalyceal bodies were found likewise in healthy control persons as well as in patients suffering from different diseases of the airways.

Cell Differentiation↗